Progress 10/01/18 to 09/30/19

Outputs
Progress Report Objectives (from AD-416): The overall objective of this project is to enhance the value of sugarcane, sweet sorghum, and energy beets, and their major commercial products sugar, biofuel and bioproducts, by improving postharvest quality and processing. Specific objectives are: 1. Develop commercially-viable technologies that reduce or eliminate undesirable effects of starch and color on sugar processing/refining efficiency and end-product quality. 2. Develop commercially-viable technologies that reduce or eliminate undesirable effects of high viscosity on sugar processing/refining efficiency and end-product quality. 3. Develop commercially-viable technologies to increase the stability and lengthen storage of sugar feedstocks for the manufacture of sugars, advanced biofuels, and bioproducts. 4. Develop commercially-viable technologies for the biorefining of sugar crop feedstocks into advanced biofuels and bioproducts. 5. Identify and characterize field sugar crop quality traits that affect sugar crop refining/biorefining efficiency and end-product quality, and collaborate with plant breeders in the development of new cultivars/ hybrids to optimize desirable quality traits. 6. Develop, in collaboration with commercial partners, technologies to improve the efficiency and profitability of U.S. sugar manufacturing and enable the commercial production of marketable products from residues (e. g., bagasse, trash) and by-product streams (e.g., low purity juices) associated with postharvest sugar crop processing. Please see Project Plan for all listed Sub-objectives. Approach (from AD-416): There are currently two major trends in the U.S. with respect to sugar crops: (1) the manufacture of higher quality raw sugar for supply to sugar refineries, and (2) the production of biofuels and bioproducts at new, flexible biorefineries. In recent years, mostly because of the increased harvesting of green sugarcane with leaves and tops, higher concentrations of starches and color have tended to occur. Some U.S. sugar refiners have placed a penalty for high starch concentrations in raw sugar. The occurrence of larger concentrations of insoluble starch in downstream factory products have exacerbated viscosity problems and reduced the efficiency of amylase enzymes to control starch. In close collaboration with industrial partners ARS scientists will develop new enzyme systems and other commercially viable technologies to control starch, viscosity, and color in factory and refinery streams, while also developing a method for measuring both insoluble and soluble starch in sugar products at the factory and refinery. Stable, storable, easily transportable, and available year-round supplies of sugar crop feedstocks, including sweet sorghum and energy beets, are needed for the conversion of sugars into substitute biofuels and bioproducts normally manufactured from fossil products. In close collaboration with industrial partners, ARS scientists will develop commercially-viable technologies for the extraction, stabilization, concentration, and fermentation of juices and syrups from sweet sorghum and energy beet feedstocks that will enable the deployment, growth, and profitability of new commercial biorefineries. Commercially-viable technologies will also be developed that are crucial to mitigate cultivar, seasonal, and environmental quality variations on feedstock performance. This is the final report for Project 6054-41000-110-00D, Developing Technologies that Enable Growth and Profitability in the Commercial Conversion of Sugarcane, Sweet Sorghum, and Energy Beets into Sugar, Advanced Biofuels, and Bioproducts. The replacement project, Improved Conversion of Sugar Crops into Food, Biofuels, Biochemicals, and Bioproducts, is currently under review and has not yet been assigned a Project Number. Progress was made on the project objectives, all of which fall under National Program 306, Component 1 (Foods), Component 2 (Non-Foods), and Component 3 (Biorefining). Progress on this project focuses on: Problem Statement 1A; define, measure, and preserve/enhance/reduce attributes that impact quality and marketability; Problem Statement 1C; new and improved food processing technologies; Problem Statement 2B; Enable technologies for (1) expanding market applications of existing biobased products, and (2) producing new marketable non-food biobased products derived from agricultural products and byproducts, and estimate the potential economic value of the new products; Problem Statement 2C; collaborate with breeders and production researchers in the development of both new cultivars/hybrids and new production practices/systems that optimize the quality and production traits of crop-derived products and byproducts for conversion into non- food biobased products; Problem Statement 3A; technologies for producing advanced biofuels (including biodiesel), or other marketable biobased products; Problem Statement 3B; technologies that reduce risks and increase profitability in existing industrial biorefineries; and Problem Statement 3C; accurately estimate the economic value of biochemical, thermolysis conversion technologies. In support of the objectives in general, the advantages of high performance analytical tools in the raw sugar factory were reviewed after four years of use and published in an industry-relevant journal so that other potential users may evaluate the benefits when troubleshooting and monitoring factory performance. In support of Objective 1, a detailed study of the various international methods for measuring total starch content in raw sugars was completed and the conclusions were published. Some of the most important findings were that current starch methods used in the sugar industry are negatively affected by natural cane and processing colorants, which often masks some measurements. Because existing industrial methods all use potato starch-based standards as references, the majority of the methods⿿ results seem interchangeable. Using the USDA Starch Research Method as a reference method, applied to factory raw sugars, ARS researchers in New Orleans, Louisiana, were able to clearly identify that a sample⿿s color affected the accuracy and precision of industrial methods of measurement currently in use. Methods that omitted a color corrective step were especially skewed. In addition, when compared, the methods are not mathematically equitable. The final findings on the development of an industrial method to measure starch in sugar products (e.g. juice, syrup, mud, and raw sugar) were published in an industry-relevant journal. Also in support of Objective 1 and Agreement 6054-41000-110-11S, the color reduction in raw sugar juice by potassium permanganate was investigated. Results show that the chemical selectivity of permanganate acts to oxidize color-inducing constituents (e.g., phenolics) while being unreactive with the desired sucrose components in the sugar cane juice. In addition, during reactions the permanganate is converted to solid phase products (called oxidation states) that can be readily removed by existing clarification steps within the sugar refining process stream. In support of Objective 3, investigation continued into the impact of storage (for more than a month) of sweet sorghum syrups prior to fermentation to fuels and chemicals. The results show that fermentation to biofuel ethanol was possible with syrups that had been stored for ten weeks under a thin layer of oil; however, syrups with 30% solids demonstrated substantial sugar degradation while little degradation occurred in syrups with 50% solids. In support of Objective 4, the study of the inhibitory effects on bioethanol production by aconitic acid (present in sweet sorghum juice and syrups) was completed. Aconitic acid has, in the past, been identified as a potential fermentation inhibitor. It was conclusively shown that aconitic acid negatively impacts fermentation rates of bioethanol-producing yeast and that the impact was pH dependent. During normal fermentation conditions, when pH levels were above 3.5, inhibition was insignificant. The final conclusions, based on study results, were published in an industry-relevant journal. Also in support of Objective 4, bacterial strains of Bacillus subtilis have been demonstrated to produce acetoin, a flavoring additive in the food industry and a precursor for industrial chemicals, using sugar beet and sweet sorghum syrups as the primary nutrient source. These strains underwent intermediate scale up for ultimate production and purification at commercial volumes. In support of Objective 5, we developed and published new statistical methods for field observation extraction and interpretation of information related to pest density and damage to sweet sorghum caused by sugarcane aphids. Also in support of Objective 5, the quality and processing attributes of sweet sorghum commercial hybrids and cultivars for the suitability of large-scale production of bioproducts in biorefineries were finalized. Two commercial sweet sorghum hybrids 105 and 106, later and earlier maturing, respectively, were compared to a popular Top 76-6 cultivar, for agronomic, quality, and processing attributes at two maturity stages. Overall, the hybrids processed similarly to the cultivar and had the additional advantages of having low starch and no side stalks. In support of Objective 6, we investigated the benefits of using a soil amendment combining biochar, worm castings and sugarcane bagasse compost products to improve soil quality. Worm castings can contribute beneficial microbes as well as physico-chemical enhancements to the soil. And compost produced from sugarcane bagasse byproducts may also be a potential soil enhancer. The texture of the worm castings and sugarcane bagasse compost was not ideal for even dispersal onto fields, however, the addition of biochar improved the texture without affecting the beneficial qualities of the worm castings. Microbial populations of the blends were found to contain taxonomic groups that contribute to plant health and did not contain human pathogens. Results indicate that blends containing 50% or less biochar will allow maintenance of beneficial microbes in stored samples. Also in support of Objective 6, we investigated the benefits of using biochar made from sugarcane bagasse as an amendment for soil-less growing media for the production of bean, squash and melon seedlings. As amendments to the soil-less growing media, the biochar functioned very well, especially at the 25% and 75% amendment levels. Even 100% biochar performed as well as the commercial soil-less growing media. Biochar mixture combinations compared favorably to the commercial media with low bulk densities and high water holding capacities. Future research is needed to evaluate these biochars for the production of additional plant species. Also in support of Objective 6, ARS researchers in New Orleans, Louisiana, developed a method of detecting biochar carbon by fluorescence and near-infrared-based chemometrics which proved to be a rapid, easy and inexpensive method to measure the amount of stable carbon stocks in agricultural soils. This method can be used to validate carbon stocks in diverse soil types in the presence of different soil amendments across the United States, allowing growers, land managers, and policy makers to quantify the carbon stocks on farms. The work was completed and the findings were published at the conclusion of the study. Also in support of Objective 6, ARS researchers in New Orleans, Louisiana, studied how compacting and ensiling impacts the stabilization of sweet sorghum bagasse. Greater bagasse stabilization translates into additional usage options, including novel applications. Bagasse stored for later use can be used as fuel, animal bedding and animal feed. Increased stability was obtained with inexpensive methods using commercially-available compactors and wrapping materials. The work was completed and the findings were published in an industry relevant journal. This work received the 2018 Southern Regional Research Center Technology Transfer Award. Accomplishments 01 Improved sugar processing. Raw sugar factories in Louisiana continue to experiment with additives to improve processing and sugar quality but microbial contamination continues to be problematic. ARS researchers in New Orleans, Louisiana, over the last three sugarcane harvesting seasons, have worked with a private company, testing a product (normally used for wastewater treatment) in the control of microbial contamination. During the last three seasons, five sugarcane factories in Louisiana applied the compound sodium permanganate to mill tandems and other factory locations. All of the participating factories recorded cleaner equipment, longer periods between required shut downs and cleaning due to contamination, reduced chemical cleaning costs, reduced use of expensive enzymes, and improved purity of sugarcane juice. After the second season of positive results, based on joint research, the private company launched a new product for the raw sugar industry. The established increase in sugar purity (or decreased loss of purity) was small but significant in terms of value. If this finding is verified in the upcoming harvesting season, it would potentially mean that a single factory would produce 2.1 million more pounds of sugar in a season which translates to $525,000 more revenue in a season. 02 Better and more efficient sugar processing. Processing sugar cane with high levels of trash such as brown and green leaves, weeds, soil and roots detrimentally impacts numerous factory operations and quality parameters of sugarcane juice processing. ARS researchers in New Orleans, Louisiana, conducted several factory trials at a local Louisiana mill that is co-located with a prototype mechanical detrasher. The studies revealed that processing efficiency improved relative to the amount of trash removed. The detrasher removed in excess of 50% of incoming trash material which allowed for higher recoverable sugar yields and stabilized variations in trash amounts providing a more consistent product for processing. The increase in processing efficiency represents a reduction of more than five days in the processing season, leading to several hundred thousand dollars in savings. In addition, the trash material, together with the bagasse (crushed sugarcane refuse), can be used to produce biochar which has applications from fuel to soil amendment and remediation. 03 Omics fingerprinting and machine-learning tools enabling a phytochemical-targeted breeding to restrict the use of pesticides, and to prevent the future outbreak of pesticide resistant strains. Since the outbreak in 2013, sugarcane aphid has become a perennial pest of sorghum production in the U.S. Although resistant varieties are available commercially and through germplasm gene banks, underlying mechanisms causing the aphid resistance are largely unknown. ARS scientists in New Orleans, Louisiana, developed advanced data mining methods to quantitatively trace target phytochemicals in a complex mixture of chemicals composing the sorghum stalk juice. Because the method is sensitive to naturally fluorescent chemicals, portable sensors could be deployed to expedite the breeding. Combined with the hyperspectral camera offering chemical fingerprints in each pixel of an image, fluorescence sensors will save time and labor costs associated with traditional visual scoring and post-harvest quality assurance/ control. 04 Selective, low-cost and user-friendly electrochemical method to rapidly classify sorghum cultivars for food and biobased products. Recently, sorghum production for the consumer food industry has drastically grown in the U.S. This market trend originates from the health-promoting properties of antioxidants in sorghum. ARS scientists in New Orleans, Louisiana, developed electrochemical methods selective to antioxidants, while ⿿masking⿝ other chemicals. The method quantitatively measures different free radical quenchers engaging in reversible redox chemistry. The developed method identified a specific subgroup of antioxidants as the putative electron-shuttling defense phytochemical in a pest resistant sorghum cultivar. 05 Spreading information about sugar. In support of overall project objectives and under advice from stakeholders, ARS researchers in New Orleans, Louisiana, authored a book chapter on the history of sugars and sweeteners, as well as a college level text book chapter on carbohydrates and the industrial production of sugars. To further educate readers, a review journal article on the positive aspects of cane sugar and sugarcane derived products in food and nutrition was also published. Educating the public and students of science advances the knowledge that ARS generates. Informing readers about the critical need for sugar by human cells for proper function and the multitude of uses for sugars, other than sweetening, ensures the public⿿s knowledge of the relevance of ARS research programs.

Impacts
(N/A)

Publications

• Uchimiya, M., Franzluebbers, A.J., Liu, Z., Lamb, M.C., Sorensen, R.B. 2019. Detection of biochar carbon by fluorescence and near-infrared-based chemometrics. Aquatic Geochemistry Journal. 24:345-361.
• Klasson, K.T. 2019. The inhibitory effects of aconitic acid on bioethanol production. Sugar Tech. 20(1):88-94.
• Cole, M.R., Eggleston, G. 2019. Development of a new industrial method to measure starch in sugar products. International Sugar Journal. 121(1442) :122-132.
• Uchimiya, M., Knoll, J.E. 2019. Rapid data analytics to relate sugarcane aphid [(Melanaphis sacchari (Zehntner)] population and damage on sorghum (Sorghum bicolor (L.) Moench). Scientific Reports. 9:370.
• Ming, L., Wang,, Y., Liu, M., Liu, Q., Xie, Z., Li, Z., Uchimiya, M., Chen, Y. 2019. Three-year field observation of biochar-mediated changes in soil organic carbon and microbial activity. Journal of Environmental Quality.
• Webber III, C.L., White Jr, P.M., Gu, M., Spaunhorst, D.J., Lima, I.M., Petrie, E.C. 2018. Sugarcane and pine biochar as amendments for greenhouse growing media for the production of bean (Phaseolus vulgaris L.) seedlings. Journal of Agricultural Science. 10(4):58-68.
• Eggleston, G., Stewart, D., Aponte, F., Montes, B., Boone, S., Verret, C. 2018. How to use and interpret the results from a high performance liquid chromatography system at a sugarcane factory. International Sugar Journal. 120(1431):210-217.
• Eggleston, G., Wartelle, L., Zatlokovicz III, J., Petrie, E., Cole, M., St Cyr, E. 2018. Quality attributes of sweet sorghum for the large-scale production of bioproducts: A 1-year comparison of commercial hybrids and a cultivar. Sugar Tech. 20(3):347-356.
• Eggleston, G., Wartelle, L., Zatlokovicz III, J., Petrie, E., Cole, M., St Cyr, E., 2018. Processing attributes and performance of sweet sorghum biomass for large-scale biorefineries: A 1-year comparison of commercial hybrids and a cultivar. Sugar Tech. 20(3):336-346.
• Eggleston, G. 2018. Positive aspects of cane sugar and sugarcane derived products in food and nutrition. Journal of Agricultural and Food Chemistry. 66:4007-4012.
• Eggleston, G., Triplett, A. 2017. Formation of polyphenol-denatured protein flocs in alcohol beverages sweetened with refined cane sugars. Journal of Agricultural and Food Chemistry. 65:9703-9714.
• Eggleston, G., Finley, J.W. deMan, J.M. 2018. Carbohydrates. In: deMan, J., Finley, J., Hurst, J., Lee, C.Y., editors. Principles of Food Chemistry, Food Science Text Series. 4th edition. New York, NY: Springer International Publishing. p. 165-229.
• Cole, M., Eggleston, G. 2018. Comparison of international methods for the determination of total starch in raw sugars: Part II. Food Chemistry. 246:99-107.
• Wright, M.S., Lima, I.M., Powell, R., Bigner, R.L. 2018. Effect of compacting and ensiling on stabilization of sweet sorghum bagasse. Sugar Tech. 20(3):357-363.
• Webber III C.L., White Jr, P.M., Spaunhorst, D.J., Lima, I.M., Petrie, E.C. 2018. Sugarcane biochar as an amendment for greenhouse growing media for the production of cucurbit seedlings. Journal of Agricultural Science. 10(2):104-115.
• Wang, Y., Tang, D., Zhang, X., Uchimiya, S.M., Yuan, X., Li, M., Chen, Y. 2018. Effects of soil amendments on cadmium transfer along the lettuce- snail food chain: Influence of chemical speciation. Science of the Total Environment. 649:801-807.
• Fang, Y., Ellis, A., Uchimiya, M., Strathmann, T.J. 2019. Selective oxidation of color-inducing constituents in raw sugar cane juice with potassium permanganate. Food Chemistry. 298:125036.
• Eggleston, G. 2019. History of sugar and sweeteners. In: Orna, M.V., Eggleston, G., Bopp, A.F., editors. Chemistry's Role in Food Production and Sustainability: Past and Present. ACS Symposium Series. Washington, DC: ACS Publications. 1314:63-74.

Progress 10/01/17 to 09/30/18

Outputs
Progress Report Objectives (from AD-416): The overall objective of this project is to enhance the value of sugarcane, sweet sorghum, and energy beets, and their major commercial products sugar, biofuel and bioproducts, by improving postharvest quality and processing. Specific objectives are: 1. Develop commercially-viable technologies that reduce or eliminate undesirable effects of starch and color on sugar processing/refining efficiency and end-product quality. 2. Develop commercially-viable technologies that reduce or eliminate undesirable effects of high viscosity on sugar processing/refining efficiency and end-product quality. 3. Develop commercially-viable technologies to increase the stability and lengthen storage of sugar feedstocks for the manufacture of sugars, advanced biofuels, and bioproducts. 4. Develop commercially-viable technologies for the biorefining of sugar crop feedstocks into advanced biofuels and bioproducts. 5. Identify and characterize field sugar crop quality traits that affect sugar crop refining/biorefining efficiency and end-product quality, and collaborate with plant breeders in the development of new cultivars/ hybrids to optimize desirable quality traits. 6. Develop, in collaboration with commercial partners, technologies to improve the efficiency and profitability of U.S. sugar manufacturing and enable the commercial production of marketable products from residues (e. g., bagasse, trash) and by-product streams (e.g., low purity juices) associated with postharvest sugar crop processing. Please see Project Plan for all listed Sub-objectives. Approach (from AD-416): There are currently two major trends in the U.S. with respect to sugar crops: (1) the manufacture of higher quality raw sugar for supply to sugar refineries, and (2) the production of biofuels and bioproducts at new, flexible biorefineries. In recent years, mostly because of the increased harvesting of green sugarcane with leaves and tops, higher concentrations of starches and color have tended to occur. Some U.S. sugar refiners have placed a penalty for high starch concentrations in raw sugar. The occurrence of larger concentrations of insoluble starch in downstream factory products have exacerbated viscosity problems and reduced the efficiency of amylase enzymes to control starch. In close collaboration with industrial partners ARS scientists will develop new enzyme systems and other commercially viable technologies to control starch, viscosity, and color in factory and refinery streams, while also developing a method for measuring both insoluble and soluble starch in sugar products at the factory and refinery. Stable, storable, easily transportable, and available year-round supplies of sugar crop feedstocks, including sweet sorghum and energy beets, are needed for the conversion of sugars into substitute biofuels and bioproducts normally manufactured from fossil products. In close collaboration with industrial partners, ARS scientists will develop commercially-viable technologies for the extraction, stabilization, concentration, and fermentation of juices and syrups from sweet sorghum and energy beet feedstocks that will enable the deployment, growth, and profitability of new commercial biorefineries. Commercially-viable technologies will also be developed that are crucial to mitigate cultivar, seasonal, and environmental quality variations on feedstock performance. Progress was made on all six objectives and their sub-objectives, all of which fall under National Program 306, Component 1 (Foods) and Components 2 (Non-Foods). Progress on this project focuses on Problem 1A; define, measure, and preserve/enhance/reduce attributes that impact quality and marketability; Problem 1C; new and improved food processing technologies; Problem 2B; Enable technologies for (1) expanding market applications of existing biobased products, and (2) producing new marketable non-food biobased products derived from agricultural products and byproducts, and estimate the potential economic value of the new products; and Problem 2C; collaborate with breeders and production researchers in the development of both new cultivars/hybrids and new production practices/systems that optimize the quality and production traits of crop-derived products and byproducts for conversion into non-food biobased products. In support of Objective 1, pilot studies were performed to remove residual amylase enzyme (from starch removal) and color using powdered activated carbons (PAC). The PAC removed significant amount of amylase from the sugar refinery liquor. Removal was dependent on PAC dose and retention time. PAC also removed color compounds. PAC preferentially removed natural sugar cane derived colorants better than process degradation colorants. Additional benefit from using PAC was a significant reduction of floating particles. Also in support of Objective 1, in collaboration with Colorado School of Mines in Golden, Colorado, and a sugar refinery, several chemicals were investigated for bleaching of sugars to remove color and make white sugar. Effectiveness of permanganate as a bleaching agent strongly depended on the starting sugar stream (raw sugar juice at the sugar mill or dissolved raw sugar at the sugar refinery), temperature, and the presence of coagulants. While permanganate removed over 90% color (measured at neutral pH) in raw sugar juice, no color removal was observed in dissolved raw sugar from the sugar refinery even at 20-fold higher permanganate loading. In support of Objective 2, high viscosity sugar streams were identified at the raw sugar factories. Subsequently, commercial enzymes were also identified that could possibly lower the viscosity. In support of Objective 3, storage of sweet sorghum syrups continued to investigate impact of storage (for more than a month) before fermentation to fuels and chemicals. Previous work had focused on storage of solutions with high sugar concentrations (60-80%) which showed little sugar degradation with time. The current work is focusing on lower concentration of sugars (approximately 30%) which represent a level that can be achieved at a lower cost as energy-intensive evaporation can be reduced. The syrups were monitored for stability of sugars. Also in support of Objective 3, stability of stored sweet sorghum bagasse (to be used as feed or animal bedding) continue to be monitored. While initial experiments only targeted a 30-day storage period, the materials have been continuously monitored longer than 30 days for weight loss and degradation. Only low degradation rates have been noted from these extended periods in the compressed bagasse materials. In support of Objective 4, it was shown that all the desired products (ethanol, butanol, acetoin, etc.) could be produced by microorganisms from sugar crops syrups in small scale (1 cup size) and larger scale fermenters (6 cup size). Sweet sorghum syrup from a biorefinery was transferred to a commercial collaborator that confirmed the results with their industrial microorganisms. Nutrient availability was found important in all of the fermentations and it was proven that the sweet sorghum and beet syrups contained some, but not all, necessary nutrients for the microbes. Most notably, nitrogen was lacking as a nutrient. A starchy sweet sorghum biorefinery products stream (sludge from clarification) was shown to improve fermentation yields when acetone and butanol were produced by bacteria without the addition of enzymes to break down the starch. In support of Objective 5, the sweet sorghum crop injuries during the growth season and the relationship to infestation of sugarcane aphids (small insects that attach sugarcane and sweet sorghum) were reviewed for the 2015 and 2016 seasons. Early season aphid population correlated to greater damage at a later growth stage. Sweet sorghum cultivars sustained less damage in 2016 planting year (compared to 2015), when higher concentrations of aconitic acid (a natural organic acid in sweet sorghum and sugarcane plants) and polyphenol (also a natural product in the sweet sorghum plant) accumulated in the stem. It is possible that these secondary (sugar being the primary) products serve as defense against aphids in the sweet sorghum plant. Advanced statistical techniques were used that could handle the large variability in the data to evaluate the information for further use. Also in support of Objective 5, methods were developed to calibrate and predict organic acids and polyphenolics in sweet sorghum juice based on light absorbance of ultraviolet and visible light. Over 24 different sweet sorghum types were included in the study with wide difference in juice composition. Of different varieties investigated, one accumulated as much as 6-fold higher aconitic acid and polyphenol-like products. Because aconitic acid is an important chemical feedstock, advanced statistical techniques were employed to predict its concentration in sweet sorghum juice, along with solids content and total sugar concentration. Non-sugar products (dissolved salts and carboxylates) accumulated in juice at the expense of fermentable sugars. Additionally, in support of Objective 5, a characterization method called cyclic voltammetry to rapidly classify sweet sorghum fermentable sugar feedstocks was investigated. The method characterizes the reactivity of the materials in a fashion that allows for types of chemicals present in the feedstocks to be identified. And these chemical types were correlated to plant health and cultivar types. For example, taller plants paralleled greater accumulation of organic carbon products, while lodged (fallen) plants had less of these products. In support of Objective 6, last tandem and crusher juice samples were collected during 2017 harvesting season from 10 Louisiana sugar cane factories. Total phenolic content was high while the sugars content was low in last tandem-crusher juice samples, suggesting that the phenolics act differently than sugar in the processing. The juices could be fermented by bacteria to produce acetone, butanol, and ethanol. Also in support of Objective 6, biochar produced by a local sugarcane mill were applied with a commercial spreader in sugarcane plots as soil amendment in 2015. Plant cane (first year) was harvested and both cane yield and sugar yield with biochar treated plots were found to be slightly greater than those for the control (no biochar treatment). First year stubble (first year after planting cane) was due to be harvested in the fall of 2017, but crop was damaged due to snow storm before harvesting. Another study was initiated to determine effects of biochar treatment in sugarcane plots with and without addition of a microbial liquid formulation produced from the fermentation of naturally occurring microorganisms. Additionally, in support of Objective 6, the fourth and final year field study was completed during 2017 harvest season. Sugar cane was grown on soils amended (single application prior to planting) with various treatments containing either biochar from bagasse, biochar from leafy residue, and fly ash (residue from factory boilers). The three soil treatments were tested either alone (just biochar or fly ash) or as mixtures of biochar with fly ash and at two application rates. All treatments were compared to controls (no treatment). It was shown that all the amendments improved the crop yield. In greenhouse studies, it was also shown that the ratooning (sprouting) ability of sugar cane improved with the addition of biochar to the soil. In support of overall project objectives and under a stakeholder agreement, sweet sorghum syrups, corn syrup, agave nectar, maple syrup, rice syrup, and other sweeteners were analyzed for protein, fat, carbohydrate, ash, mineral content, anti-oxidant activity, and other factors to determine the potential for introducing sweet sorghum syrup as a liquid sweetener and nutritional food ingredient. Sweet sorghum syrup was found to contain high levels of magnesium, potassium, and calcium. It also contained significant levels of anti-oxidant compounds. Accomplishments 01 Stabilization of sweet sorghum bagasse for use as animal bedding. The majority of sweet sorghum bagasse is underutilized because more is produced than can be practically reapplied to fields as a soil amendment. Unused bagasse accumulates, taking up valuable space in a processing facility. ARS researchers in New Orleans, Louisiana, tested a portable inexpensive trash compactor for compacting bagasse. With no addition of chemicals or microbes the natural conditions of the compressed bales permitted ensiling and stabilization after 30 days storage under ambient conditions. The stakeholder scaled the process up and is now selling ensiled bagasse as animal bedding to a horse breeder. 02 Sweet sorghum syrup as nutrient-rich sweetener. Many sugar syrups such as corn syrup, maple syrup, etc. can be used as food sweetener but often they are low in nutritional value. ARS researchers in New Orleans, Louisiana, determined the nutritional content of a large number of commercial syrups as well as sweet sorghum syrups. It was found that sweet sorghum syrup contained twice as much protein as other syrups. It also contained high levels of potassium, magnesium, and iron; all of which are important from a nutritional standpoint. Anti-oxidant activity was also high in the sweet sorghum syrups. These results are valuable as they set the stage for the introduction of sweet sorghum syrup as a commercial liquid sweetener. The results were transferred to key stakeholders, who now use it as information to promote sweet sorghum syrup as a sweetener. 03 Using liquid permanganate to prevent degradation of sugarcane juice results in significant savings for raw sugar factories. The presence of microorganisms in sugarcane juice degrades sugar, producing gummy- like substances that interfere with processing, require additional chemical usage, and increase maintenance. ARS researchers in New Orleans, Louisiana, in collaboration with a private company and with the help of raw sugar factory staff, used liquid permanganate as a processing aid. The techniques, which were tested at full scale, resulted in lower levels of microbes, improved clarification, reduced chemicals usage, and increased sugar yield. 04 Removal of color from sugar beet extract remaining after betaine recovery. Betaine is an amino acid used as a food supplement and it is recovered from sugar beet molasses at some sugar beet refineries. Once the betaine is recovered, the remaining liquid is called beet extract and is dark in color. ARS researchers in New Orleans, Louisiana, determined the powdered active carbon dosage and operating conditions required to remove 50% of the color, as had been targeted by the stakeholder. These results are important as it allows the beet extract to be cleaned and the resulting liquid can be processed to produce additional sugar, thus improving overall sugar recovery. The results were shared with the stakeholder who will consider implementing the process. 05 Monitoring aphid population and crop injury impacting sweet sorghum. The recent outbreak of sugarcane aphids reportedly caused several billion dollars of losses in sorghum production, and several millions of dollars in additional expenses for insecticides. ARS researchers in New Orleans, Louisiana, utilized advanced statistical tools to describe the aphid population and damage timecourses (from planting to harvest), relationships between aphid population and crop damage, and influence of crop varieties and environmental factors on aphid population and damage. Developed statistical tools can be incorporated into the integrated pest management and best management practice against sugarcane aphids. 06 Pilot scale removal of impurities from sugar refinery liquor by powdered activated carbon. Sugar refineries (where they are making white granulated sugar) must remove color whether they are naturally derived or process formed. In addition, it is desired to remove the enzyme amylase that often enters the refinery in the raw sugar from a raw sugar mill. ARS researchers in New Orleans, Louisiana, used powdered active carbon to remove both color and residual amylase enzyme. Sixty four to 100% of the enzyme was removed and 55% of the colored compounds were removed, resulting in a significantly cleaner liquor. This finding is important as the sugar industry has a desire to produce ultra-pure products for special applications. The results were shared with key stakeholders at meetings and with information that would allow further scale-up. 07 Utilization of sweet sorghum biorefinery byproducts for solvent and biofuel production. In the production of sweet sorghum syrup, the juice is first cleaned by a process called clarification. The clarification uses lime and generates a low-value byproduct called mud that is rich in solids, starch, and sugars. ARS researchers in New Orleans, Louisiana, used this material to make acetone and butanol by fermentation with results twice as good when compared to processed sugars. The compounds represent important industrial solvents, can be use as biofuels, or can be used as chemical building blocks for other chemicals. The relative high product concentration will reduce the cost of recovery and may advance the technology faster. 08 Chemical and remote sensing techniques to evaluate sweet sorghum quality. Sweet sorghum is grown for production of liquid sweeteners and generation of inexpensive sugars for biofuel and biochemical production. It is also possible that valuable co-products could be developed to support the sweet sorghum refinery. ARS researchers in New Orleans, Louisiana, evaluated 24 different sweet sorghum varieties and developed methods to calibrate and predict the concentrations of chemicals in sweet sorghum that could serve as building blocks for advance biobased chemicals. The developed chemical and remote sensing methods could replace time-consuming visual scoring in the field by breeders.

Impacts
(N/A)

Publications

• Klasson, K.T., Qureshi, N., Powell, R., Heckemeyer, M., Eggleston, G. 2018. Fermentation of sweet sorghum syrup to butanol in the presence of natural nutrients and inhibitors. Sugar Tech. 20(3):224-234.
• Qureshi, N., Klasson, K.T., Saha, B.C., Liu, S. 2018. Butanol production from sweet sorghum bagasse (SSB) with high solids content: part I � comparison of liquid hot water pretreatment with dilute sulfuric acid. Biotechnology Progress. 34(4):960-966. doi: 10.1002/btpr.2639.
• Qureshi, N., Klasson, K.T., Saha, B.C., Liu, S. 2018. High solid fed-batch butanol fermentation with simultaneous product recovery: part II - process integration. Biotechnology Progress. 34(4):967-972. doi: 10.1002/btpr.2643.
• Eggleston, G., Legendre, B., Godshall, M.A. 2017. Sugar and other sweeteners. In: Kent, J.A., editor. Handbook of Industrial Chemistry and Biotechnology. 13th edition. New York, NY: Springer International Publishing. pp. 933-978.
• Lima, I.M., White Jr, M. 2017. Sugarcane bagasse and leaf residue biochars as soil amendment for increased sugar and cane yields. International Sugar Journal. 119(1421):382-390.
• Lima, I.M., Bigner, R.L., Wright, M.S. 2017. Conversion of sweet sorghum bagasse into value-added biochar. Sugar Tech. 19(5):553-561.
• Wright, M., Lima, I., Bigner, R. 2017. Stability and use of sweet sorghum bagasse. Sugar Tech. 19(5):451-457.
• Eggleston, G., Montes, B., Heckemeyer, M., Triplett, A., Stewart, D., Lima, I., Cole, M. 2017. Problems, control, and opportunity of starch in the large scale processing of sugarcane and sweet sorghum. International Sugar Journal. 119:624-633.
• Eggleston, G., Boone, S., Triplett, A., Heckemeyer, M., Powell, R., Wright, M., 2018. Preliminary study on the use of inexpensive, unsaturated vegetable oils as surface sealants in the long- and short-term storage of syrup feedstocks from sweet sorghum. Sugar Tech. 20(3):235-251.
• Hass, A., Lima, I.M. 2018. Effect of feed source and pyrolysis conditions on properties and metal sorption by sugarcane biochar. Environmental Technology & Innovation. 10:16-26.
• Lima, I.M., Wright, M.S. 2018. Microbial stability of worm castings and sugarcane filter mud compost blended with biochar. Cogent Food & Agriculture. 4(1):1-14.
• Eggleston, G., Lima, I., Sarir, E., Thompson, J., Zatlokovicz III, J., St Cyr, E. 2017. Use of activated carbon to remove undesirable residual amylase from refinery streams. Zuckerindustrie. 142:96-103.
• Uchimiya, M., Knoll, J.E. 2018. Prediction of carboxylic and polyphenolic chemical feedstock quantities in sweet sorghum. Energy and Fuels. 32:5252- 5263.
• Uchimiya,M., Noda, I., Orlov, A., Ramakrishnan, G. 2018. In situ and ex situ 2D infrared/fluorescence correlation monitoring of surface functionality and electron density of biochars. ACS Sustainable Chemistry & Engineering. 6:8055-8062.

Progress 10/01/16 to 09/30/17

Outputs
Progress Report Objectives (from AD-416): The overall objective of this project is to enhance the value of sugarcane, sweet sorghum, and energy beets, and their major commercial products sugar, biofuel and bioproducts, by improving postharvest quality and processing. Specific objectives are: 1. Develop commercially-viable technologies that reduce or eliminate undesirable effects of starch and color on sugar processing/refining efficiency and end-product quality. 2. Develop commercially-viable technologies that reduce or eliminate undesirable effects of high viscosity on sugar processing/refining efficiency and end-product quality. 3. Develop commercially-viable technologies to increase the stability and lengthen storage of sugar feedstocks for the manufacture of sugars, advanced biofuels, and bioproducts. 4. Develop commercially-viable technologies for the biorefining of sugar crop feedstocks into advanced biofuels and bioproducts. 5. Identify and characterize field sugar crop quality traits that affect sugar crop refining/biorefining efficiency and end-product quality, and collaborate with plant breeders in the development of new cultivars/ hybrids to optimize desirable quality traits. 6. Develop, in collaboration with commercial partners, technologies to improve the efficiency and profitability of U.S. sugar manufacturing and enable the commercial production of marketable products from residues (e. g., bagasse, trash) and by-product streams (e.g., low purity juices) associated with postharvest sugar crop processing. Please see Project Plan for all listed Sub-objectives. Approach (from AD-416): There are currently two major trends in the U.S. with respect to sugar crops: (1) the manufacture of higher quality raw sugar for supply to sugar refineries, and (2) the production of biofuels and bioproducts at new, flexible biorefineries. In recent years, mostly because of the increased harvesting of green sugarcane with leaves and tops, higher concentrations of starches and color have tended to occur. Some U.S. sugar refiners have placed a penalty for high starch concentrations in raw sugar. The occurrence of larger concentrations of insoluble starch in downstream factory products have exacerbated viscosity problems and reduced the efficiency of amylase enzymes to control starch. In close collaboration with industrial partners ARS scientists will develop new enzyme systems and other commercially viable technologies to control starch, viscosity, and color in factory and refinery streams, while also developing a method for measuring both insoluble and soluble starch in sugar products at the factory and refinery. Stable, storable, easily transportable, and available year-round supplies of sugar crop feedstocks, including sweet sorghum and energy beets, are needed for the conversion of sugars into substitute biofuels and bioproducts normally manufactured from fossil products. In close collaboration with industrial partners, ARS scientists will develop commercially-viable technologies for the extraction, stabilization, concentration, and fermentation of juices and syrups from sweet sorghum and energy beet feedstocks that will enable the deployment, growth, and profitability of new commercial biorefineries. Commercially-viable technologies will also be developed that are crucial to mitigate cultivar, seasonal, and environmental quality variations on feedstock performance. Conversion of Sugar Crop Solutions to Biofuel and Bioproducts (Objective 4). The biofuels and bioproducts ethanol, butanol, succinic acid (precursor to 1,4-butanediol), and acetoin were tested with simulated sugar solutions and diluted sugar crop syrups in bench-scale reactors. All products could be produced from the simulated solutions. To aid in the work, bench-scale equipment was modified so that multiple fermentation experiments could be conducted under controlled conditions. Aconitic acid (a potential fermentation inhibitor) was the only major organic acid found in the commercial sugar solutions and sweet sorghum juices. Under normal fermentation conditions, aconitic acid does not impact fermentation; however, if the conditions are very acidic (like the unique operation conditions in Brazilian sugarcane bioethanol plants) it will have a negative impact. A portion of the ethanol research was presented at the Symposium on Biotechnology for Fuels and Chemicals Meeting on Advances in Sugar Crop Processing and Conversion, and at the Annual Meeting of the Society of Industrial Microbiology and Biotechnology. Conversion of Sugar Beet Juice Sugars to Acetoin (Objective 4). Acetoin is a compound that contributes to the flavor of butter, and is used as a food additive to impart that quality to baked goods and other foods. We demonstrated that two Bacillus strains of bacteria could convert glucose in beet thick juice (syrup) to acetoin under laboratory-scale fermentation conditions. Beet juice was mixed with decreasing concentrations of glucose, and data showed that beet juice alone was enough to support conversion of beet sugar to acetoin. These results confirmed that the beneficial product acetoin can be cost-effectively produced from beet juice with little to no supplementation with added sugar. Future work will include scaling up this technology. Identification of New Uses for Sugarcane Biochar (Objective 3). Vermiculture (composting using worms) is sometimes used to improve soil quality since worm castings (organic fertilizer) are known to enhance soil quality and structure through both beneficial microbes and soil nutrients. To commercialize worm castings as a soil amendment, it is necessary for these characteristics to be stabilized through storage. We demonstrated the storage stability and more effective dispersal of the worm castings onto soils, by producing blends with sugarcane biochar at different ratios. While microbial counts for worm castings significantly decreased during storage, additions of up to 25% of biochar doubled microbe counts during a 3 month storage study. In a subsequent study it was determined that blends containing up to 75% biochar did not significantly inhibit microbial stability. The addition of biochar also increased the carbon content of the blends and improved soil structure. Sugarcane biochar produced from bagasse (fibrous by-product) and leafy trash at a Louisiana sugarcane factory was also applied to fields growing both plant (first year) cane and first ratoon (second year) cane at three commercial farms. Biochar was applied in three different forms: powder with molasses, powder without molasses, and pellets with molasses. Sugarcane was hand-harvested and juice extracted. Data is currently being analyzed and the fields will be monitored for an additional year. It is expected that the addition of biochar to the field will enhance soil quality, improve sugarcane growth and/or sugar yield. Biochar was also produced from sugarcane bagasse and leafy residues in a pilot plant and applied it to a grower�s field. Fly ash (residue from factory boilers) was also added as a treatment to determine its contribution to the yield of the sugarcane crop compared to the biochar. Mixtures of fly ash and biochar were applied at two levels and compared to no treatment. Plant cane (first year growth), first ratoon (second year growth), and second ratoon (third year growth) crops were harvested in a three year field study and juices was extracted with roller milling. Analysis included stalk length and weight, and juice was analyzed for Brix (% soluble solids), purity, and fiber content. Statistical analysis of all data has been completed. Although there were no significant differences between treatments, biochar improved the ratooning (re-growth) ability of sugarcane over the three year period. Additionally fly ash addition to soil did not have a deleterious effect in sugarcane or sugar yield. One additional year will be harvested and data collected for this study. Final progress report for Agreement 58-6054-6-0021 (Objective 1). The application of chemical ripeners is an important component of sugarcane cultivation management in the United States to increase sucrose concentrations. Little information was available on the effects of ripener on starch and color quality parameters critical to both factory and refinery processing. A large, two-year field study was conducted on the effect of two chemical ripeners with differing modes of action on sugarcane: Polado (glyphosate chemical) that suppresses the formation of new tissue at the top of the stalk, and Moddus (trinexapac-ethyl chemical) that interferes with stalk elongation. The ripeners were applied to nine commercial sugarcane varieties cultivated in South Louisiana, USA, and hand-harvested 4 to 7 weeks after ripener application. Results from the first year of the study showed that adding either ripener increased total starch in stalks by 20.7%, although this was not statistically significant because of a very strong varietal effect. Field variability in the starch values was much higher than variability for Brix (percent soluble solids), pH, and color values, even in the untreated juices. The ripeners had less effect on pH and color than starch. No significant differences occurred with ripener treatment for color measured at pH 4.0, 7.0, 8.5, and 9.0, although color variability increased with ripener application. Analysis of the second year of study is currently being completed to verify the first year trends. Progress report for Agreement 6054-41000-110-25N in collaboration with Louisiana State University (Objective 6). Activities included the initial stage planning of a full day workshop to be held at ARS, New Orleans, Louisiana, as part of the Water Environment Technical Annual Conference and Exposition (WEFTEC) in September 2018. A pre-proposal was submitted in July 2017. This workshop will bring together various experts in the field of thermochemical biomass conversion into value-added products and energy. Progress report for Agreement 58-6435-4-005 (Objective 1). In collaboration with the National Agriculture and Food Research Organization, the Ministry of Agriculture, Forestry, and Fisheries, Japan, specialized methods based on chemical oxidation-reduction probes and nuclear magnetic resonance spectroscopic analyses. The methods were then successfully used to identify the chemical functionalities responsible for the antioxidant capacity of sugarcane-derived value-added products, and different forms of phosphorus nutrients in agricultural wastes. Final progress report for Agreement 58-6054-5-0021 (Objective 1). Near Infrared Spectroscopy (NIRs) that rapidly measures the amount of various quality parameters in sugarcane juice and biomass has potential to benefit the U.S. sugar industry. In a two year study, together with an industrial collaborator, we took core samples from three Louisiana factories each week across the 3-month processing season. The samples were transported to the NIR pilot plant instrument and analyzed and compared to conventional juice analyses at the factory. All the pressed- out juices were also analyzed for color at pH 4, 7, 8.5, and 9, conductivity ash, and mannitol. The levels of leafy trash in samples were also shown to be detected by NIR which means there is high potential for NIR to be used as an automatic cane payment system in Louisiana. Final report for Agreement 58-6054-5-0022 (Objective 1). We completed the development of a new method to rapidly, precisely, and accurately measure total, soluble, and insoluble starch at the factory and refinery. The method is based on chemical assisted microwaving and the estimated cost is only 4 cents per analysis. The method has already been submitted as a new method to the International Commission for Uniform Methods in Sugar Analysis and is being transferred to factories. Final progress report for Agreement 58-6054-6-019 (Objective 6). In collaboration with West Virginia State University, biochars were developed from sugar crop residues to make sorbent materials, and both the feedstock and pyrolysis conditions were evaluated for their ability to remove selected heavy metals and oxyanions from water. Findings were presented at the Association of 1890 Research Directors 18th Research Symposium, 2017, in Atlanta, Georgia, and at the 2017 American Society of Sugar Cane Technologists meeting in New Orleans, Louisiana, and a manuscript is being written. Final progress report for Agreement 6054-41000-110-01O (Objective 4). In collaboration with Oak Ridge Institute for Science and Education, a special enzyme system was developed to convert starch in processing products, by-products, and waste materials from sweet sorghum syrup manufacturing. The developed enzyme system was able to convert all the starch into sugars. Application of the enzyme method followed by fermentation of the syrup to ethanol by yeast, increased the ethanol yield by up to 2.5 fold. Accomplishments 01 Established the continuous use of a High Performance Liquid Chromatography (HPLC) system at a sugarcane factory to accurately and rapidly measure sugars. On request from industry, ARS researchers in New Orleans, Louisiana, in collaboration with a Louisiana sugarcane factory and Louisiana State University, established the first HPLC at a Louisiana sugarcane factory. A HPLC sugar method was developed and established to measure mannitol, glucose, fructose, and sucrose in a run time of 10 minutes at the factory. For the best accuracy, separate and higher dilutions are needed to quantitate sucrose due to its considerably higher concentration in sugar products (except molasses). Training was formalized and conducted because it was essential for operations and analyses and this included basic sugar chemistry, major sugarcane deterioration reactions, and color formation in the factory, since an analytical technique is only useful if the results are interpreted properly. A simplified chart was created and provided to the factory staff to help interpret the results. The HPLC system allowed the factory to: (i) monitor sucrose losses in �real time�, (ii) rapidly identify sugarcane deterioration via mannitol (sugar alcohol) measurement, (iii) rapidly monitor loss of sucrose in molasses and dextranase (enzyme that breaks down unwanted dextran polymer) applications, and (iv) explain difficult samples more easily. In the 2016 processing season, the use of HPLC allowed the detection of excess sucrose losses of approximately 0.49%, in one of three juice clarification tanks at the factory, which is conservatively equivalent to $460,000 loss in sucrose yields per year. This caused the factory staff to retrofit the tank to reduce heat spots and sucrose losses, and this alone has paid for the cost of the HPLC system. 02 Ensiling sweet sorghum bagasse. As the U.S. production of sweet sorghum increases, there are associated increases in the accumulation of low value bagasse which is a fibrous by-product. Processers need to quickly stabilize the bagasse after it is produced so it can be converted into useful bioproducts after the harvest season. ARS researchers in New Orleans, Louisiana, used ensile (preservation of biomass in a silo) technology to store sweet sorghum bagasse. This was successful and resulted in anaerobic conditions in which the bagasse can be stably stored for subsequent use as animal bedding. Utilizing inexpensive, commercially available compacting equipment, an anaerobic environment was successfully created and maintained that was sufficient enough to inhibit microbial degradation of the stored bagasse. Key factors identified were the compaction rate and the thickness of the packaging material surrounding the bales. Based on the processors� standard milling practices, bagasse from both single and double pass millings were ensiled. It was determined that although single pass bagasse did stabilize, double pass bagasse was ensiled more efficiently because it was finer and easier to compact. The collaborating sorghum producer is now using the demonstrated conditions to scale-up to commercial scale. 03 Identification of quality and processing traits in sweet sorghum to aid breeders and industrial processors. Since 2013, insects such as sugarcane aphids have infested sweet sorghum in the Midwest and Southeast USA, considerably reducing crop yields. ARS researchers in New Orleans, Louisiana, and Tifton, Georgia, discovered that the chemical compounds trans-aconitic and oxalic acids were found to be quality traits of sweet sorghum which indicate pest resistance to sugarcane aphids. Chemical fingerprints for trans-aconitic acid and oxalic acid can be used to rapidly screen for resistant lines to develop new sweet sorghum cultivars, and aphid resistant lines have already been identified. Higher yields of trans-aconitic and oxalic acids and other secondary products (dissolved salts, organic acids, phenolics, and amino acids) were accompanied by lower yields of primary products (fermentable sugars) in sweet sorghum stalk juice. The planting date was also important. These findings have provided a recommendation for Southern Coastal Plane growers to employ later planting date (from April to June) to maximize the stem sugar yields, depending on the degree of interactions between the cultivar and the planting date. 04 Evaluation of commercial biocides in sugarcane juice to determination of economic feasibility. The microbial contamination of extracted sugarcane juice is a serious problem in raw sugar manufacture because it causes expensive sugar losses and the formation of degradation products that interfere with processing. In 2016, U.S. sugarcane factories requested information on biocides to control bacterial growth during milling. ARS researchers in New Orleans, Louisiana, in collaboration with a sugarcane factory and a processing aid company, evaluated potassium permanganate as a biocide. Potassium permanganate was shown to reduce the growth of both gram negative and positive bacteria in sugarcane juice and bagasse. The combination of hydrogen peroxide and sodium hypochlorite chemicals also reduced bacterial growth and additionally decolorized juice. An economic assessment of these findings from the factory has provided a conservative estimate that if potassium permanganate is added on a 24 hour basis at a sugarcane factory it could save $280,000 in sucrose losses alone per year. Further studies are needed before implementation at the factory. 05 Causation of floc formation in alcohol beverages sweetened with refined cane sugars. Alcohol beverages are high value-added products with large domestic and international markets. Consumers expect the beverage to be clear and will most likely be deterred from purchasing the beverage if flocs (suspended large particles) are present. Unfortunately, with the declining use of high fructose corn syrup as a beverage sweetener in the USA, the sporadic appearance of floc from refined cane sugars has been increasing and it remains a technical problem that is not easily managed. ARS researchers in New Orleans, Louisiana, were approached by a large American alcohol manufacturer to improve understanding of the root cause or causes of floc formation. Insoluble and soluble starch, fat, inorganic ash, oligosaccharides (short chain sugars), percent soluble solids, and pH were shown not to be involved in the prevailing floc formation mechanism. There were strong relationships between floc formation and protein content of the sugar as well as the sugar�s color indicator value which is an indirect measure of polyphenolic and flavonoid colorants. The ethanol in the beverages were shown to induce the denaturation of the protein and create more hydrophobic polyphenol binding sites and, therefore, more floc. Polyphenol-protein flocs are known to occur in ciders, wines, and beers. A tentative mechanism for floc formation was advanced by molecular probing with a floc active protein and polyphenol, as well as polar, non-polar, and ionic solvents. By knowing the cause of floc formation solutions, such as activated carbon, have now been put forward to removing these components at the sugar refinery or at the distillery. Cane Land Distilling Company in Baton Rouge, Louisiana, is already using these research findings. 06 Development of an industrial method to measure insoluble and soluble starch in sugar products at a sugarcane factory or refinery. In recent years, starch impurity concentrations in sugarcane raw sugar have been increasing in the United States. ARS researchers in New Orleans, Louisiana, showed that existing starch methods used in the international sugar industry do not accurately measure total starch because they cannot efficiently solubilize the insoluble starch well and are also limited by the color of the factory product. At the request of industry, a rapid, precise, and accurate industrial method was developed, based on chemical assisted microwaving, to measure total, soluble, and insoluble starch at the factory and refinery. The industrial method compared favorably (less than 6.5% difference in accuracy and precision) with the USDA Starch Research Method but is much less expensive because the relatively expensive probe sonicator in the USDA Starch Research Method was replaced with less expensive and readily available chemicals. The new method costs only 4 cents per analysis. The method has already been submitted as a new method to the International Commission for Uniform Methods in Sugar Analysis. 07 Development of a novel starch breakdown enzyme system to increase fermentation yields from by-products obtained during sweet sorghum syrup manufacture. In collaboration with an industrial collaborator, ARS researchers in New Orleans, Louisiana, identified seeds, bagasse (fibrous product from roller milling), juice sediment and clarification mud, both by-products of sweet sorghum large-scale processing, as rich in starch. Thus these industrial by-products could be used as untapped sources of fermentable sugar. A hydrolysis and saccharification (starch breakdown) system consisting of five enzymes was developed specifically for the sweet sorghum industry and found to increase fermentable sugars by 50-75% and double ethanol yields using the industrial by-products. It was conservatively estimated that less than $20 worth of enzymes would be needed per ton of starchy by-products. It was also found that chemical or microbial impurities usually concentrated in these by- products did not negatively affect laboratory hydrolysis, saccharification, and fermentation experiments. These findings have also been successfully applied to the primary industrial products of sweet sorghum juices and syrups. 08 Development of technologies to control color in product streams at the sugarcane factory and refinery. The removal of naturally-derived or process-derived sugarcane colorants from raw sugar, by separation methods or chemical breakdown methods, is the primary goal of sugar refiners. ARS researchers in New Orleans, Louisiana, developed new advanced oxidation processes (AOPs) to enhance product decolorization at sugarcane factories where there are less stringent constraints to the addition of processing aids compared to the refinery. Four different AOPs (permanganate, hydrogen peroxide, persulfate, and peroxymonosulfate chemicals) were screened under different processing conditions. The permanganate exhibited an order of magnitude greater decolorization than the other AOPs. In addition to chemically breaking down the cane-derived colorants by forming reactive free radicals, permanganate enhanced the juice clarification processes by forming colloidal particles. The findings could be used by sugarcane factories but further factory studies are now needed. 09 Starch formation and interference with carbonatation clarification at a sugar refinery. Raw sugars with >250 parts per million (ppm) total starch (long chain polysaccharide) cause problems during clarification (using carbonate) at the refinery. Using raw sugars with a large range in quality, ARS researchers in New Orleans, Louisiana, demonstrated that existing analytical methods used to predict refining performance do not accurately represent the processing challenges from high-starch concentrations. By conducting a large, three-part study, it was determined that: (i) insoluble starch (starch form before it is swollen) is most deleterious to press filtration after the clarification process, and (ii) soluble starch binds calcium ions and limits the formation of calcium carbonate mud, thus producing small calcium carbonate crystals which make filtration worse. Raw sugars containing 35-65% insoluble starch were found to be more deleterious to carbonatation clarification and press filtration, although soluble starch disrupted the carbonatation chemical reactions. These findings support the need for new refinery methods to accurately depict both soluble and insoluble starch�s behavior during carbonatation clarification and press filtration as well as the need to measure total, soluble, and insoluble starch in raw sugars and refinery products. 10 Identification of fermentation inhibitors. Aconitic acid, naturally present in sweet sorghum juice and syrup, has been mentioned as a fermentation inhibitor that slows down biofuel production rates but very little proof existed. ARS researchers in New Orleans, Louisiana, with a commercial partner proved that juice clarification (chemical treatment of juice to remove a variety of turbid compounds) did not remove aconitic acid. The ARS researchers also confirmed that fermentation inhibition existed and that it was linked to one of four chemical versions of aconitic acid that only occurs in acid environments. This explains why some researchers have found that aconitic acid was an inhibitor to fermentation while other researchers did not. This is important because it provides the emerging sweet sorghum juice and syrup fermentation industry with one solution to the problem of slow fermentation rates, which is to carry out the fermentation in less acid environments.

Impacts
(N/A)

Publications

• Cole, M.R., Eggleston, G., Petrie, E., Uchimiya, S.M., Dalley, C. 2016. Cultivar and maturity effects on the quality attributes and ethanol potential of sweet sorghum. Biomass and Bioenergy. 96:183-192.
• Cole, M., Eggleston, G., Triplett, A. 2017. Analytical evaluation of current starch methods used in the international sugar industry: Part I. Food Chemistry. 228:226-235.
• LeBlanc, J., Uchimiya, M., Ramakrishnan, G., Castaldi, M.J., Orlov, A. 2016. Across-phase biomass pyrolysis stoichiometry, energy balance, and product formation kinetics. Energy and Fuels. 30:6537-6546.
• Guo, M., He, Z., Uchimiya, S.M. 2016. Introduction to biochar as an agricultural and environmental amendment. In: Guo, M., He, Z., Uchimiya, S. M., editors. Agricultural and Environmental Applications of Biochar: Advances and Barriers. SSSA Special Publication 63. Madison, WI:Soil Science Society of America, Inc. p. 1-14.
• Wright, M.S., Lima, I.M., Bigner, R.L. 2016. Microbial and physicochemical properties of sugarcane bagasse for potential conversion to value-added products. International Sugar Journal. (2016):10-18.
• Guo, M., He, Z., Uchimiya, S.M. 2016. Preface for "Agricultural and environmental applications of biochar: Advances and barriers." In: Guo, M., He, H., Uchimiya, S.M., editors. SSSA Special Publication 63. Madison, WI:Soil Science Society of America, Inc. p. v-viii.
• Boone, S., Klasson, K.T., St Cyr, E., Montes, B., Pontiff, K., Legendre, D. , Wright, M. 2017. Limiting sucrose loss in Louisiana raw sugar factories: Are biocides necessary? International Sugar Journal. 119(1420):288-293.
• Bhattacharya, S.S., Kim, K.H., Das, S., Uchimiya, M., Jeon, B.H., Kwon, E., Szulejko, J.E. 2016. A review on the role of organic inputs in maintaining the soil carbon pool of the terrestrial ecosystem. Journal of Environmental Management. 167:214-227.
• Eggleston, G., Wartelle, L., St Cyr, E. 2016. Detecting adulterated commercial sweet sorghum syrups with ion chromatography oligosaccharide fingerprint profiles. Separations. 3(20):1-16.
• Uchimiya, M., Wang, M.L. 2016. Roles of conjugated double bonds in electron-donating capacity of sorghum grains. African Journal of Agricultural Research. 11(24):2146-2156.
• Cole, M.R., Eggleston, G., Rathke, T., Naiki, J., Triplett, A., St Cyr, E. 2016. How the physical forms of starch affect filterability at a carbonatation refinery. Part II: simulated carbonatation filtration. International Sugar Journal. (2016):650-659.
• Guo, M., Uchimiya, S.M., He, Z. 2016. Agricultural and environmental applications of biochar: Advances and barriers. In: Guo, M., Uchimiya, S.M. , He, Z., editors. Agricultural and Environmental Applications of Biochar: Advances and Barriers. SSSA Special Publication 63. Madison, WI:Soil Science Society of America, Inc. p. 495-504.
• Wright, M.S. 2017. Effect of a biocide treatment on microbes in sweet sorghum juice. African Journal of Agricultural Research. 12(13):1074-1078.
• Klasson, K.T. 2017. Impact of potential fermentation inhibitors present in sweet sorghum sugar solutions. Sugar Tech. 19(1):95-101.
• Uchimiya, M., Hiradate, S., Chou, C.C. 2016. Polyphenolic reductants in cane sugar. Austin Food Sciences. 1(5):1022.
• Klasson, K.T. 2017. Biochar characterization and a method for estimating biochar quality from proximate analysis results. Biomass and Bioenergy. 96:50-58.
• Kim, K., Kumar, P., Szulejko, J.E., Adelodun, A.A., Junaid, M.F., Uchimiya, M.M., Chambers, S. 2017. Toward a better understanding of the impact of mass transit air pollutants on human health. Chemosphere. 174:268-279.
• Muley, P.D., Henkel, C.E., Aguilar, G., Klasson, K.T., Boldor, D. 2016. Ex situ themo-catalytic upgrading of biomass pyrolysis vapors using a traveling wave microwave reactor. Applied Energy. 183:995-1004.

Progress 10/01/15 to 09/30/16

Outputs
Progress Report Objectives (from AD-416): The overall objective of this project is to enhance the value of sugarcane, sweet sorghum, and energy beets, and their major commercial products sugar, biofuel and bioproducts, by improving postharvest quality and processing. Specific objectives are: 1. Develop commercially-viable technologies that reduce or eliminate undesirable effects of starch and color on sugar processing/refining efficiency and end-product quality. 2. Develop commercially-viable technologies that reduce or eliminate undesirable effects of high viscosity on sugar processing/refining efficiency and end-product quality. 3. Develop commercially-viable technologies to increase the stability and lengthen storage of sugar feedstocks for the manufacture of sugars, advanced biofuels, and bioproducts. 4. Develop commercially-viable technologies for the biorefining of sugar crop feedstocks into advanced biofuels and bioproducts. 5. Identify and characterize field sugar crop quality traits that affect sugar crop refining/biorefining efficiency and end-product quality, and collaborate with plant breeders in the development of new cultivars/ hybrids to optimize desirable quality traits. 6. Develop, in collaboration with commercial partners, technologies to improve the efficiency and profitability of U.S. sugar manufacturing and enable the commercial production of marketable products from residues (e. g, bagasse, trash) and by-product streams (e.g., low purity juices) associated with postharvest sugar crop processing. Please see Project Plan for all listed Sub-objectives. Approach (from AD-416): There are currently two major trends in the U.S. with respect to sugar crops: (1) the manufacture of higher quality raw sugar for supply to sugar refineries, and (2) the production of biofuels and bioproducts at new, flexible biorefineries. In recent years, mostly because of the increased harvesting of green sugarcane with leaves and tops, higher concentrations of starches and color have tended to occur. Some U.S. sugar refiners have placed a penalty for high starch concentrations in raw sugar. The occurrence of larger concentrations of insoluble starch in downstream factory products have exacerbated viscosity problems and reduced the efficiency of amylase enzymes to control starch. In close collaboration with industrial partners ARS scientists will develop new enzyme systems and other commercially viable technologies to control starch, viscosity, and color in factory and refinery streams, while also developing a method for measuring both insoluble and soluble starch in sugar products at the factory and refinery. Stable, storable, easily transportable, and available year-round supplies of sugar crop feedstocks, including sweet sorghum and energy beets, are needed for the conversion of sugars into substitute biofuels and bioproducts normally manufactured from fossil products. In close collaboration with industrial partners, ARS scientists will develop commercially-viable technologies for the extraction, stabilization, concentration, and fermentation of juices and syrups from sweet sorghum and energy beet feedstocks that will enable the deployment, growth, and profitability of new commercial biorefineries. Commercially-viable technologies will also be developed that are crucial to mitigate cultivar, seasonal, and environmental quality variations on feedstock performance. Testing of Biofuels and Bioproducts with Sugar Solutions and Diluted Industrial Syrups. The biofuels and bioproducts ethanol, butanol, succinic acid (precursor to 1,4-butanediol), and acetoin were tested with chemical sugar solutions and diluted sugar crop syrups. A portion of the ethanol research were presented at the Symposium on Biotechnology for Fuels and Chemicals, Meeting on Advances in Sugar Crop Processing and Conversion, and at the Annual Meeting of the Society of Industrial Microbiology and Biotechnology. A week-long technical training trip was completed with an ARS-Peoria collaborator conducting butanol fermentation. The outcome allowed two commercially relevant organisms to be selected for butanol production and these have now been tested in the laboratory. Succinic acid was produced in an advanced reactor system using an organism, known for high productivity, from an ARS-Wyndmoor collaborator. Over sixty organisms were evaluated by a Japanese collaborator and two were selected for further study. They have now been tested on both sugar solutions and sugar crop syrup at New Orleans, Louisiana, with good results. Considering all the results obtained last year, most findings indicate that there was no significant difference between fermentation performance due to sugar source, except in the case of succinic acid. In the latter case, it was found that the organism did not convert sucrose (major sugar in syrups) in its native form. Thus, it will be required to break the sucrose into its smaller parts (glucose and fructose) before conversion. In some cases, nutrients in the diluted sugar crop syrups were not sufficient to support the growth of the microorganism used and needed to be supplemented. Physical Chemical and Microbial Properties of Stored Sugarcane Bagasse for Energy Production. Large amounts of excess sugarcane bagasse can be piled and stored from year to year outside sugarcane factories. In the previous year, we determined marked differences between higher (HHV) and lower (LHV) fuel heating values of bagasse due to the presence of moisture. High moisture levels negatively impacting bagasse fuel characteristics, and differences between HHV and LHV were as high as 57% for covered versus 81% for uncovered bagasse. Factory staff have concerns on the impact of the additional amounts of mud in the fuel value of the bagasse. For this reason, 2015 bagasse samples are being analyzed for fuel value and other pertinent chemical properties. This research has major implications for factories processers, who need the stored bagasse to burn in boilers and provide energy and steam to start-up the next processing season. Development of an Industrial Method to Measure both Insoluble and Soluble Starch. A new method was developed, that was urgently requested by industry, to measure insoluble, soluble and total starch in sugarcane products at the factory or refinery. The method was favorably tested against the USDA Research Method, and is less expensive. This new thermo-chemical method is very rapid at 2 min per sample and costs only 4 cents per sample. The method will now be validated following the protocols of the International Commission for Uniform Methods in Analysis and also validated for transferability at several sugarcane factories in 2016. Composting of Sweet Sorghum Bagasse. Samples of sweet sorghum bagasse were collected over the 2015 harvesting season and incubated in a commercially available composter across a period of 9 months. Samples were inspected regularly and at the end of the 9 month period it was determined that no significant beneficial conversion had occurred and the experiment was terminated. New Uses of Value-added Biochar from Sugarcane Bagasse and Trash. In 2016, we were approached by a Vermiculture and Animal farmer in Kentwood, LA on the potential to add value to worm castings (organic fertilizer) by blending with sugarcane biochar manufactured from bagasse and leafy trash. Worm castings were collected and blended with biochar at various volume- based percentages then stored at ambient temperature (25 degrees centigrade). After 42 days storage, microbial counts of 100% worm castings unwantonly dropped by approximately 85% and the addition of up to 10% biochar did not change this. At 25% addition of biochar to worm castings there was a significant enhancement of the microbial population, which may be due to biochar binding harmful microbial waste products. Biochar is beneficial because it is less expensive than worm castings, and blends stabilize the beneficial microbes in worm castings. Field Application of Value-Added Sugarcane Biochar. Sugarcane bagasse and leafy trash remain untapped by-products and residues, respectively. Three forms of biochar, manufactured from both bagasse and trash (pelletized, ground with and without molasses), were applied to sugarcane fields from two farms in South Louisiana in June 2015. Trenches were dug and biochar applied on both sides of each treated row, then covered with soil. Treated applications included first and second year sugarcane at both farms. In October 2015, soil was cored and sampled from each farm and stalks were counted. In November 2015, a representative sample of ten stalks was hand harvested from each treatment and processed at Houma. Analysis included stalk length and diameter, internode length, and stalk weight. Juice was analyzed for Brix (% dissolved solids), purity, and fiber content. Juice was plated for microbial presence. This study is being continued in a second year to determine continued effects of residual biochar. Identification of Microorganisms from Sugarcane and Sweet Sorghum Juices to Target Control Protocols. The microbial contamination of extracted sugar crop juice is a serious problem because it causes expensive sugar losses and the formation of degradation products that interfere with processing. We previously showed that commercial biocides do not work effectively. Identification of the microbes was necessary for more targeted control protocols. Using sophisticated methods, microbes were identified and measured in sugar crop juices. In addition, a sanitation questionnaire was developed and distributed to sugarcane factories in LA. The questionnaire will enable identification of unique processes at each factory that affect microbial populations. This research will lead to more efficient and effective methods to control microorganism populations and sugar losses in juices. Development of Laboratory Diffusion Method to Evaluate Pre-treated Sugar Crops. To perform diffusion experiments, a pilot-scale multi-feedstock (sweet sorghum, sugar cane, and energy beets) diffuser for juice extraction is needed. Because the manufacture of this custom-made system is expensive, industrial sponsorship is being sought. Meanwhile, a simple, flexible laboratory method was developed that mimics the countercurrent operation of a continuous diffuser into discrete sections. This method can yield diffusion data of interest, as well as optimum diffusion parameters which are not yet available particularly for sweet sorghum. The pre-treated (either sliced energy beets/shredded sweet sorghum) sugar crop is exposed to a series of sugar juices of decreased concentration and diffusion is allowed until there is no concentration gradient. At each stage of decreased sugar juice concentration, juice sub-samples can be collected and analyzed for fiber, polysaccharide, and other impurity contents. Variables studied include sample pre-treatment (shredding density, slice thickness), diffusion packing density, diffusion temperature, cultivar/variety and ratio of juice to sugar crop. This method has already been applied to energy beets. Final Progress Report on NIFA Grant. Nanotechnology is used in every industrial sector today, including agriculture. Industrial nanomaterials (very small particles less than 1 micron in size) enter agricultural soils as a sludge amendment or agrochemicals/fertilizers. Biochar has been promoted as the tool to convert U.S. soils into the soil found in archaeological site of Brazil (Amazonian terra preta). This project investigated how these foreign constituents influence the property of U.S. agricultural soils and associated ecosystems. Both biochars and nanomaterials changed the size of soil particle, resulting in the changes in key soil properties including the retention of water and nutrients. Furthermore, biochar helped food crops accumulate industrial nanomaterials to impact the nanotoxicology in the upper food chain of edible plants as well as the earthworm. Accomplishments 01 Technology for the long-term storage of sweet sorghum syrup. Sweet sorghum syrup is vulnerable to surface microbial spoilage during storage because of its rich sugar medium, and this represents a major technical challenge to the commercial, large-scale manufacture of biofuels and bioproducts from this feedstock. ARS scientists at New Orleans, Louisiana, with an industrial collaborator at Heckemeyer Mill, Sikeston, Missouri, showed that adding only a 1.7 cm layer of inexpensive soy bean, canola, or sunflower oil as a surface sealant, allowed sweet sorghum syrup containing 65% dissolved solids to be stored for at least 1 year at ambient temperature. Heckemeyer Mill is now using this novel technology to store syrup in 7,500 gal tanks. 02 Control of insoluble and soluble sugarcane starch by the application of amylases to factory clarification processes. The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has made the control of starch by amylase enzymes much more difficult. ARS scientists at New Orleans, Louisiana, with industrial collaborators Amano Enzyme in Japan and Alma sugarcane factory in LA, showed that both high-temperature (HT) and intermediate-temperature (IT) stable amylases can hydrolyze insoluble and soluble starch in clarified juice at 96 �C during the first 10 minutes before substantial breakdown of amylase protein. Unfortunately, however, even at 1 ppm, HT amylases can cause unwanted carry-over (residual) amylase activity in the raw sugar. Two new technologies were developed to prevent the occurrence of carry- over amylase in end-products: (i) the simultaneous addition of IT amylase to the next-to-the-last evaporator and last evaporator to hydrolyze both soluble and insoluble starch, and (ii) the addition of powdered activated carbon to remove the residual amylase protein with the added benefits of removing cane-derived phenolic/flavonoid colorants and insoluble starch. 03 Identification of quality and processing traits in sweet sorghum to aid breeders and industrial processors. Sweet sorghum is a promising feedstock crop for the manufacture of biofuels and bioproducts. ARS scientists at New Orleans, Louisiana, and at Houma, Louisiana, completed a two-year study on four commercial cultivars at five physiological stages. Juice quality and physical crop traits essential to processing and fermentation were strongly influenced by environmental and cultivar interactions; total sugars were influenced by cultivar and maturity interactions. Brix (per cent dissolved solids) in juice was shown not to be a valid in-field harvesting indicator to predict stalk maturity. Total sugars and starch in extracted juice were greatest at the hard dough (late) maturity stage but strongly depended on cultivar. 04 Testing of biofuels and bioproducts with sugar solutions and diluted industrial syrups. The biofuels and bioproducts ethanol, butanol, succinic acid (precursor to 1,4-butanediol), and acetoin were tested with sugar solutions and diluted industrial syrups from sugarcane and sugar beets. ARS scientists at New Orleans, Louisiana, and at Peoria, Illinois, transferred butanol fermentation technology, which allowed two commercially relevant organisms to be selected for butanol production and be tested in the laboratory. Also, succinic acid was produced in an advanced reactor system using an organism, known for high productivity, from an ARS-Wyndmoor collaborator. Out of sixty organisms evaluated by a Japanese collaborator, two were selected, and shown to give high yields with sugar solutions and sugar crop syrup fermentation feedstocks. Overall, except for succinic acid, most findings indicated that there was no significant difference between fermentation performance due to sugar source. For succinic acid manufacture it is necessary to break the sucrose into glucose and fructose, before conversion. In some cases, nutrients in the diluted sugar crop syrups were not sufficient to support the growth of the microorganism used and needed to be supplemented. These results will help to establish the large-scale manufacture of biofuels and bioproducts from sugar feedstocks. 05 Research method to measure insoluble and soluble starch in sugar products validated against international starch methods and used to pinpoint problems in carbonatation clarification process of sugarcane refineries. In recent years, starch impurity concentrations in sugarcane have been increasing in the United States. ARS scientists at New Orleans, Louisiana, developed a rapid, precise, and accurate research method based on microwave-assisted sound waves, to measure total, insoluble and soluble starch. This new research method has been successfully used to find commercially-viable solutions to reduce or eliminate profound detrimental effects on insoluble starch. It has also been used to pinpoint where soluble and insoluble starch cause problems during the carbonatation clarification system at sugarcane refineries. The method was also successfully compared to six, international starch methods commonly used in the sugar industry to measure total starch only, and results presented to the International Commission for Uniform Methods in Sugar Analysis. 06 Method to detect adulteration and misbranding of sweet sorghum syrups. Adulteration of sweet sorghum syrups has a strong economic impact on the industry and undeniable nutritional consequences. Furthermore, as sweet sorghum is a promising feedstock for the production of biofuels and bioproducts, the adulteration of syrups with high starch substitutes such as high fructose corn syrup (HFCS) could impact bio- yields. Some commercial sweet sorghum syrups can be fraudulently adulterated with inexpensive sugar syrups, particularly HFCS or corn syrup, and sold at a relatively low market price or even mis-branded. ARS scientists at New Orleans, Louisiana, showed that ion chromatography with integrated pulsed amperometric detection (IC-IPAD) fingerprint profiles can detect adulteration. Such profiles are extremely selective, sensitive, and reliable. By using five characteristic marker chromatography peaks of HFCS, in combination with a low sucrose peak, adulterated and mis-branded syrups were identified. The analysis of syrup samples containing 7% soluble solids allowed the detection of as low as 10% HFCS adulteration, which is within the lower limit of adulteration before action is taken. Detection of adulteration will allow for more fair competition, as well as stable markets and regional economies. 07 Developed methods for breeders and industrialists to characterize quality traits of sweet sorghum. Methods to rapidly, simply, and inexpensively measure quality traits in the new sweet sorghum feedstocks for the manufacture of biofuels and bioproducts are urgently needed. Breeders need them to develop better hybrids and cultivars and industrialists need them to measure feedstock quality and for grower payment systems. ARS scientists at New Orleans, Louisiana, developed several multivariate statistical methods for breeders to predict the key sweet sorghum genotype traits on-farm. Developed methods will replace currently available near-infrared and chromatography techniques by inexpensive fluorescence and light absorption methods. Developed methods will allow breeders and growers to predict the concentration of sugars or select impurities including aconitic acids, based on the maximum light absorption/reflectance by a juice/bagasse sample, and vice versa. Established chemometric (advanced statistical pattern recognition) methods were extended to sorghum grain samples to understand the chemical traits responsible for the pest (aphid/worm/ bird) resistance. 08 Development of technologies to control color at the factory and refinery. Removal of cane or process-derived colorants, by separation methods or chemical breakdown methods, are the primary goal of sugarcane refiners. For optimum color removal, the chemical structure of colorants needs to be identified first. An ARS scientist at New Orleans, Louisiana, by using an advanced spectroscopic technique, revealed a relatively small amount of fingerprint phenolic structures (cane-derived colorants). Based on the identified structures, several different rapid, easy, and inexpensive research methods were developed to quantify the target colorants at the refinery. Based on the determined chemical structure and oxidation-reduction chemistry of the color, advanced oxidation technology, which is well established in water treatment, was determined to be the most promising chemical color removal approach that will continuously produce radicals to break down the color without forming toxic by-products.

Impacts
(N/A)

Publications

• Lima, I., Klasson, K.T., Uchimiya, M. 2016. Selective release of inorganic constituents in broiler manure biochars under different post-activation treatments. Journal of Residuals Science & Technology. 13(1):37-48.
• Uchimiya, M. (2015) Biochar production technology: An overview. In: Ok, Y. S., Uchimiya, M., Chang, S., and Bolan, N., editors. BIOCHAR: Production, Characterization and Applications. London:Taylor & Frances. p. 45-66.
• Yi, P., Pignatello, J.J., Uchimiya, M., White, J.C. 2015. Heteroaggregation of cerium oxide nanoparticles and nanoparticles of pyrolyzed biomass. Environmental Science and Technology. 49:13294-13303.
• Uchimiya, M., Liu, Z., Sistani, K. 2016. Field-scale fluorescence fingerprinting of biochar-borne dissolved organic carbon. Journal of Environmental Management. 169:184-190.
• Jones, K., Ramakrishnan, G., Uchimiya, M., Orlov, A., Castaldi, M.J., Leblanc, J., Hiradate, S. 2015. Fate of higher-mass elements and surface functional groups during the pyrolysis of waste pecan shell. Energy and Fuels. 29:8095-8101.
• Cole, M.R., Eggleston, G., Borges, E., Thompson, J., Rathke, T., Naiki, J., Triplett, A. 2016. How the physical forms of starch affect filterability at a carbonatation refinery. Part I: Filterability of industrial sugars. International Sugar Journal. CXVIII(1407):204-213.
• Eggleston, G., Heckemeyer, M., St Cyr, E., Wartelle, L. 2016. Case Study: Commercialization of sweet sorghum juice clarification for large-scale syrup manufacture. Sugar Tech. 18(3):249-257.
• Eggleston, G., Lima, I. 2015. Sustainability issues and opportunities in the sugar and sugar-bioproduct industries. Sustainability. 7:12209-12235.
• Eggleston, G., Andrzejewski, B., Cole, M., Dalley, C., Sklanka, S., St Cyr, E., Chung, Y., Powell, R. 2015. Novel storage technologies for raw and clarified syrup biomass feedstocks from sweet sorghum (Sorghum bicolor L. Moench). Biomass and Bioenergy. 81:424-436.
• Cole, M.R., Rose, I., Chung, Y.J., Eggleston, G. 2015. A structured approach to target starch solubilization and hydrolysis for the sugarcane industry. Journal of Food Chemistry. 166:165�172.
• Hale, A.L., Viator, R.P., Eggleston, G., Hodnett, G., Stelly, D., Boykin, D.L., Miller, D. 2016. Estimating broad sense heritability and investigating the mechanism of genetic transmission of cold tolerance using mannitol as a measure of post-freeze juice degradation in sugarcane and energycane (Saccharum spp.). Journal of Agricultural and Food Chemistry. DOI: 10.1021/acs.jafc.5b03803.
• Lima, I., Eggleston, G., Sarir, E., Donado, C.A., Thompson, J., St Cyr, E. 2016. Mechanism of removal of undesirable residual amylase, insoluble starch, and select colorants from refinery streams by powdered activated carbons. International Sugar Journal. 118:352-362.
• Eggleston, G., Cole, M., Toyamasu, T., Triplett, A., Montes, B., Wartelle, L., Stewart, D. 2016. Conquering the control of insoluble and soluble starch with novel applications of amylase. International Sugar Journal. 120:570-579.

Progress 10/01/14 to 09/30/15

Outputs
Progress Report Objectives (from AD-416): The overall objective of this project is to enhance the value of sugarcane, sweet sorghum, and energy beets, and their major commercial products sugar, biofuel and bioproducts, by improving postharvest quality and processing. Specific objectives are: 1. Develop commercially-viable technologies that reduce or eliminate undesirable effects of starch and color on sugar processing/refining efficiency and end-product quality. 2. Develop commercially-viable technologies that reduce or eliminate undesirable effects of high viscosity on sugar processing/refining efficiency and end-product quality. 3. Develop commercially-viable technologies to increase the stability and lengthen storage of sugar feedstocks for the manufacture of sugars, advanced biofuels, and bioproducts. 4. Develop commercially-viable technologies for the biorefining of sugar crop feedstocks into advanced biofuels and bioproducts. 5. Identify and characterize field sugar crop quality traits that affect sugar crop refining/biorefining efficiency and end-product quality, and collaborate with plant breeders in the development of new cultivars/ hybrids to optimize desirable quality traits. 6. Develop, in collaboration with commercial partners, technologies to improve the efficiency and profitability of U.S. sugar manufacturing and enable the commercial production of marketable products from residues (e. g, bagasse, trash) and by-product streams (e.g., low purity juices) associated with postharvest sugar crop processing. Please see Project Plan for all listed Sub-objectives. Approach (from AD-416): There are currently two major trends in the U.S. with respect to sugar crops: (1) the manufacture of higher quality raw sugar for supply to sugar refineries, and (2) the production of biofuels and bioproducts at new, flexible biorefineries. In recent years, mostly because of the increased harvesting of green sugarcane with leaves and tops, higher concentrations of starches and color have tended to occur. Some U.S. sugar refiners have placed a penalty for high starch concentrations in raw sugar. The occurrence of larger concentrations of insoluble starch in downstream factory products have exacerbated viscosity problems and reduced the efficiency of amylase enzymes to control starch. In close collaboration with industrial partners ARS scientists will develop new enzyme systems and other commercially viable technologies to control starch, viscosity, and color in factory and refinery streams, while also developing a method for measuring both insoluble and soluble starch in sugar products at the factory and refinery. Stable, storable, easily transportable, and available year-round supplies of sugar crop feedstocks, including sweet sorghum and energy beets, are needed for the conversion of sugars into substitute biofuels and bioproducts normally manufactured from fossil products. In close collaboration with industrial partners, ARS scientists will develop commercially-viable technologies for the extraction, stabilization, concentration, and fermentation of juices and syrups from sweet sorghum and energy beet feedstocks that will enable the deployment, growth, and profitability of new commercial biorefineries. Commercially-viable technologies will also be developed that are crucial to mitigate cultivar, seasonal, and environmental quality variations on feedstock performance. In recent years, starch impurity concentrations in sugarcane have been increasing in the United States. ARS scientists at the Southern Regional Research Center in New Orleans, Louisiana, showed that the increases in insoluble starch concentrations are causing the greatest problems in sugarcane factories and refineries. ARS scientists have developed a rapid, precise, and accurate research method, using microwave-assisted sound waves, to measure total, insoluble and soluble starch. The method was validated for use in a diverse array of industrial products including fibrous waste, juices, syrups, and crystalline sugars. By using this method, the amounts of insoluble starch in raw sugars manufactured by sugarcane factories were shown to be extremely underestimated by current industrial starch methods used in the U.S. industry. Insoluble starch in white, refined sugars was shown often not to be detected by current methods. This new research method is now being used to find commercially- viable solutions to reducing or eliminating profound detrimental effects on insoluble starch. Factory and refinery staff have also requested for an industrial method that will be based on this research method. There has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. The use of activated carbons to remove residual amylase activity was investigated for the sugar industry to remove measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon had the additional benefits of removing color and insoluble starch. This is the first technology developed to remove undesirable insoluble starch. Microorganisms for producing ethanol, butanol, and 1,4-butanediol were obtained and tested for capability to produce the stated products from pure sugar solutions. The fermentation techniques and protocols were obtained from collaborators or the literature. The technique to investigate the production of acetoin from sugar was transferred to a collaborator for testing. The following constitutes the progress made on subordinate projects. The microbial contamination of extracted sugarcane juice is a problem at the factory because it causes sugar losses and the formation of degradation products that interfere with processing. Although commercial biocides were added to juice in U.S. sugarcane factories to control microbial growth and contamination, their efficiency had long been questioned. Three types of biocides, based on bleach, sodium carbamate, and hops, obtained from Louisiana sugar factories were evaluated. The biocides were studied individually and in combinations at two Louisiana factories. None of the commercial biocides worked effectively in the factories whereas heat and precipitation reactions during the juice clarification process were effective. The use of biocides as surface disinfectants is now being studied at Louisiana factories. Sweet sorghum syrup is vulnerable to surface microbial spoilage during storage because of its rich sugar medium, and this represents a major technical challenge to the commercial, large-scale manufacture of biofuels and bioproducts from this feedstock. Syrups manufactured from clarified juice are more stable than those manufactured from raw juice. Heat pasteurization of juice at different temperatures was investigated, and it was found that heating sweet sorghum juice between 60 and 70 degrees centigrade for 30 min would allow the storage of sweet sorghum juice for at least 72 hours and offer operational flexibility to sweet sorghum processers. As it had previously shown that soybean oil on the surface of syrups can stabilize and preserved sweet sorghum syrups for up to 1 year, different surface size layers of inexpensive and readily available soybean, canola, and sunflower oil on clarified sweet sorghum syrup were further investigated. Differences in oil type were found and the greater the surface layer the better the storage. The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has made the control of starch by amylase enzymes more difficult. Intermediate-temperature (IT) stable amylases can break down a certain amount of both insoluble and soluble starch in clarified juice at 96 degrees centigrade for the first 10 minutes before substantial deactivation of the enzyme, without causing unwanted no carry-over (residual) amylase activity. Novel combinations and doses of IT stable amylase added simultaneously to a factory�s clarifier tank, next-to-the- last evaporator, and last evaporator at a factory, were shown to aid the control of both insoluble and soluble starch, and have been recommended to sugarcane industrialists. Insoluble and swollen starch were shown to be the main contributors to viscosity increases from starch in both the sugarcane factory and refinery. The direct addition of amylase to a process was undisputedly shown to cause small but meaningful reductions in viscosity of syrup which has major consequences for increased sugar recovery. Different combinations of amylase applications at multiple points in a factory were shown to reduce viscosity. Quality traits of sweet sorghum can strongly affect processing performance and yields and quality of end-products. Two commercial sweet sorghum hybrids, bred to provide abundant seed to growers and higher yields, were shown to offer similar quality and performance attributes as a popular sweet sorghum cultivar. All the sweet sorghum genotypes were very susceptible to environmental changes. The presence of side stalks dramatically reduced crop yields, and detrimentally affected quality and processing performance. Breeders now have more information on which quality traits to breed for, and processers have more knowledge on factors that strongly affect processing which will underpin development of processing tools and aids for their control. Gold and fullerene nano-particles (less than one micron in size) are widely used by the medical, microelectronic, and catalysis industry. Both of these nano-particles are negatively charged, and therefore, expected to interact with biochar sorbents. Gold nano-particles (30nm) were created by boiling chlorauric acid solution in the presence of citric acid. Between pH 3 and 5, 300 degrees centigrade biochar rapidly and irreversibly retained the gold nano-particles. The uptake of gold nano- particles progressively decreased as a function of burning temperature up to 500 degrees centigrade, and then slightly increased for biochar produced at 700 degrees centigrade. At each pyrolysis temperature, the uptake of gold nano-particles at pH 7 was negligibly low. Strong bonding interaction involving hydrogen atom was the cause of observed interactions. Results will be used to develop precious metal-mining technology and in the contaminant risk assessment tools. Sophisticated high-resolution nuclear magnetic resonance techniques specific to proton, carbon, and phosphorus were utilized to visualize specific chemicals responsible for desirable and undesirable functions of bioenergy feedstocks. In sugarcane and grape seed-derived antioxidants, specific redox couple was identified to cause reversible electron transfer reactions. In pecan shell and manure agricultural wastes and value-added products, five different phosphorus species were determined to be the forms of nutrients available to the food crops. After identification of ideal gasification conditions that yield desirable attributes of biochar from poultry broiler litter, several biochar samples were generated. The samples were analyzed and tested for the following: carbon, hydrogen, oxygen, nitrogen and sulfur; proximate analysis: fixed carbon, volatile carbon, ash and moisture; quantification of elemental leaching from acid wash and rain water wash treatments, surface area, pH and copper ion adsorption. The best performing sample was identified for additional testing. In addition to supplying needed heat to condition the broiler houses, the farmer can save money on purchasing natural gas, and the gasifier can also produce a biochar as a by-product. The identified attributes of the biochar produced position it as a marketable product such as air adsorbent for waste water and air remediation, a soil amendment, or possibly a feed supplement. Laboratory scale column adsorption studies were carried out with pure gas ammonia and nitrogen gases to determine poultry manure and plant- based carbons with the best adsorption efficiency along with the comparative studies of commercial grade carbons. Preliminary studies utilizing a chamber acid-trap system were carried out on the adsorption capacities of the carbons with relation to direct poultry manure emissions which are comprised primarily of nitrogen gases. This research represents an opportunity to not only re-use poultry manure, but also to treat the emissions from or within poultry houses. The use of activated carbon in the removal of ammonia gas in poultry houses had long been discarded primarily due to the high cost and low efficiency of the carbons. The results of the study demonstrate the potential for a cyclical waste utilization strategy in using broiler litter activated carbon to capture ammonia given off from litter. Accomplishments 01 Evaluate the effectiveness of commercial biocides in sugarcane juice. The microbial contamination of extracted sugarcane juice is a serious problem at the factory because it causes expensive sugar losses and the formation of degradation products that interfere with processing. Although commercial biocides were added to juice in U.S. sugarcane factories to control microbial growth and contamination, their efficiency had long been questioned. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, evaluated three types of biocides, based on bleach, sodium carbamate, and hops, obtained from Louisiana sugar factories. The biocides were studied individually and in combinations at two Louisiana factories. None of the commercial biocides worked effectively in the factories whereas heat during the juice clarification process did. This research has already had impact with numerous U.S. sugar factories discontinuing the use of the tested commercial biocides. A conservative estimate is that, on average, each factory has saved $46,8100 per year which equates to a saving of $515, 000 per year in Louisiana alone. 02 Commercialization of sweet sorghum juice clarification for large-scale syrup manufacture. The precipitation and burning of insoluble starch granules from sweet sorghum juice on heating coils prevented the large- scale manufacture of syrup at Heckemeyer Mills, Sikeston, Missouri. An ARS scientist from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, showed that both starch concentration and granule size contributed to processing problems. The introduction of juice de-aeration, settling, and the USDA clarification process enabled the large-scale manufacture of syrup. Quality and processing differences due to cultivar and environmental effects were also overcome and this assured continual supply of clarified syrups to customers. This research allowed Heckemeyer Mills to become fully operational in 2015. 03 Technology to store sweet sorghum syrup. Sweet sorghum syrup is vulnerable to surface microbial spoilage during storage because of its rich sugar medium, and this represents a major technical challenge to the commercial, large-scale manufacture of biofuels and bioproducts from this feedstock. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, with an industrial collaborator at Heckemeyer Mill, Sikeston, Missouri, showed that adding only a 1 cm layer of soy bean oil as a surface sealant, allowed sweet sorghum syrup containing 65% dissolved solids to be stored for at least 9 months at ambient temperature. The fungal, yeast, and bacterial microorganisms responsible for syrup deterioration were identified. Handling of the syrup before storage was found to be crucial. Heckemeyer Mill will now use this novel technology to store syrup in 7,500 gal tanks. 04 Control of insoluble and soluble sugarcane starch with novel combinations of amylase. The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has made the control of starch by amylase enzymes much more difficult. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, with industrial collaborators Amano Enzyme in Japan and Alma sugarcane factory in Louisiana, showed that intermediate- temperature (IT) stable amylases can break down a certain amount of both insoluble and soluble starch in clarified juice at 96�C for the first 10 min before substantial deactivation of the enzyme, and causes no carry-over (residual) amylase activity. Novel combinations and doses of IT stable amylase added simultaneously to a factory�s clarifier tank, the next-to-last, and last evaporator at a factory were shown to aid the control of both insoluble and soluble starch and have been recommended to sugarcane industrialists. Small but meaningful reductions in viscosity of syrup were also shown to occur inside the evaporator where the amylase was directly applied. At the present time, this is the only processing tool to control insoluble starch in factories. 05 Insoluble starch detrimentally affects refinery processes. It was previously considered in the sugarcane industry that soluble starch was solely responsible for filtration problems associated with the carbonatation clarification process at a refinery. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, with three refinery collaborators from New Orleans, Louisiana, Gramercy, Louisiana, and Savannah, Georgia, showed that insoluble starch also negatively affects carbonatation refining. Specifically, the total starch concentration and the ratio of soluble and insoluble starch are implicated. The majority of raw sugars entering the refinery contain 35-65% insoluble starch which can persist across the whole refinery and into refined sugars. Soluble starch negatively affects carbonatation reactions by limiting the production of calcium carbonate crystal, an internal filter-aid needed to remove impurities from the dissolved raw sugar. Insoluble starch decreases carbonation efficiency similarly to soluble starch but also clogs and coats the press filter membrane, both of which are detrimental to energy and processing costs at the refinery. The effects of different starch forms in raw sugars are complicated and may be exacerbated by other raw sugar impurities. This work provides strong evidence that refiners need to measure insoluble starch as well as soluble starch in their raw materials. 06 Quality of stored sugarcane bagasse for energy production. Large amounts of excess sugarcane bagasse are piled and stored from year to year outside sugarcane factories. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, in collaboration with three Louisiana sugarcane factories, determined the microbial and physical/chemical properties of covered and uncovered piles of sugarcane bagasse stored for 9 months. Due to lower moisture content, covered bagasse prevented the sugarcane bagasse from deteriorating and maintained the fuel value of the bagasse much better than uncovered bagasse. This has major implications for factories and processers, who need the stored bagasse to burn in boilers and provide energy and steam to start-up the next processing season. 07 Ethanol fermentation of sugars and clarified sweet sorghum juice. Multiple U.S. stakeholders want to maintain ethanol in their portfolio of biofuels manufactured from sugar crops. ARS scientists in the Commodity Utilization Research Unit in New Orleans, Louisiana, showed that sugars in diluted, clarified sweet sorghum syrup were excellent raw materials for the production of ethanol from a commercial yeast strain. The sweet sorghum syrup had an acid buffering effect, allowing the fermentation to progress more rapidly than expected at optimal conditions. Although organic acids are present in some sugar crop juices, only acetic acid had a major, detrimental impact on the fermentation. These results will allow stakeholders to consider clarified sweet sorghum sugar solutions (with anticipated amount of organic acids) to be fermentable to bioethanol by commercial yeast strains. 08 Methods for breeders and industrialists to characterize quality traits of sweet sorghum. Methods to rapidly, simply and inexpensively measure quality traits in the new sweet sorghum feedstocks for the manufacture of biofuels and bioproducts are urgently needed. Breeders need them to develop better hybrids and cultivars and industrialists need them to measure feedstock quality and for grower payment systems. An ARS scientist from the Commodity Utilization Unit in New Orleans, Louisiana, developed methods to measure the redox reactivity, antioxidant activity, and the degree of aromaticity (UV/visible and fluorescence spectral features) of sweet sorghum juices and seeds. A quantitative correlation was observed between these parameters and the amount of condensed tannins and flavonoids, which are related to color, in seeds. For sweet sorghum juice, total organic carbon/nitrogen and electrical conductivity analyses provided more accurate alternatives to traditional methods to measure total sugar and salt contents, while employing the instrumentations available at the factory. Advanced spectroscopic technique (nuclear magnetic resonance) confirmed quinone/ dihydroxybenzene as the redox couple observable in the newly developed method. 09 Genotype, maturity, and environmental effects on sweet sorghum quality and processing. Quality traits of sweet sorghum can strongly affect processing performance and yields and quality of end-products. By conducting two field trials, ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, in collaboration with NexSteppe hybrid company and USDA-ARS-Houma, showed there were strong genotype and maturity effects for sweet sorghum quality and processing performance. Sweet sorghum genotypes were very susceptible to environmental changes. The presence of side stalks dramatically reduced crop yields, quality, clarification and evaporation performance of sweet sorghum. Starch was an important source of untapped fermentable sugars in sweet sorghum and it was shown that starch concentration and size in juice varied by genotype and, generally, was not affected by weather or maturity. Breeders now have more information on which quality traits to breed for, and processers have more knowledge on factors that strongly affect processing which will underpin development of processing tools and aids for their control. 10 Sugarcane bagasse and trash for value-added products. Sugarcane bagasse and leafy trash remain untapped by-product and residues, respectively, associated with harvesting and processing of sugarcane. ARS scientists from the Commodity Utilization Unit of the Southern Regional Research Center in New Orleans, Louisiana, produced biochar from these two biomass sources in a pilot plant via slow pyrolysis and applied to the field at 0, 4, and 5% rates. Besides improvements in soil health, such as mineral nutrition, carbon content, water holding capacity, significant improvements in both sugarcane crop and sugar yields were observed when using the value-added biochar. Benefits to both sugarcane growers and processors result from the production of valued by-products from pyrolysis of sugarcane trash and bagasse as well as enhancing the sugarcane industry�s role in sustainable, renewable energy markets.

Impacts
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Publications

• Uchimiya, M., Hiradate, S., Antal, Jr., M.J. 2015. Influence of carbonization methods on the aromaticity of pyrogenic dissolved organic carbon. Energy and Fuels. 29:2503-2513.
• Cole, M.R., Hobden, J.A., Warner, I.M. 2015. Recycling antibiotics into GUMBOS: A new combination strategy to combat multi-drug resistant bacteria. Molecules. (20):6466-6487.
• Uchimiya, M., Hiradate, S., Antal, Jr., M.J. 2015. Dissolved phosphorus speciation of flash carbonization, slow pyrolysis, and fast pyrolysis biochars. ACS Sustainable Chemistry & Engineering. 3:1642-1649.
• Cantrell, K.B., Hunt, P.G., Uchimiya, S.M., Novak, J.M., Ro, K.S. 2012. Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar. Bioresource Technology. 107:419-428.
• Eggleston, G., Borges, E. 2015. Multiple applications of ion chromatography oligosaccharide fingerprint profiles to solve a variety of sugar and sugar-biofuel industry problems. Journal of Agricultural and Food Chemistry. 63:2841-2851.
• Boue, S.M., Shih, B.Y., Burow, M., Eggleston, G., Lingle, S.E., Pan, Y., Daigle, K.W., Bhatnagar, D. 2013. Postharvest accumulation of resveratrol and piceatannol in sugarcane with enhanced antioxidant activity. Journal of Agricultural and Food Chemistry. 61:8412-8419.
• Wang, M.L., Cole, M.R., Tonnis, B.D., Pinnow, D.L., Xin, Z., Davis, J., Hung, Y., Yu, J., Pederson, G.A., Eggleston, G. 2014. Comparison of stem damage and carbohydrate composition in the stem juice between sugarcane and sweet sorghum harvested before and after late fall frost. Journal of Sustainable Bioenergy Systems (JSBS). 4:161-174.
• White Jr, P.M., Potter, T.L., Lima, I.M. 2015. Sugarcane and pinewood biochar effects on activity and aerobic soil dissipation of metribuzin and pendimethalin. Industrial Crops and Products. 74(2015):737-744. DOI: 10. 1016/j.indcrop.2015.04.022
• van Heerdan, P.D.R., Eggleston, G., Donaldson, R.A. 2014. Ripening and postharvest deterioration. Chapter 4. In: Moore, P.H., Botha, F.C., editors. Sugarcane: Physiology, Biochemistry, and Functional Biology. Hoboken, NJ:Wiley-Blackwell. p. 55-84.
• Legendre, B., Eggleston, G., Birkett, H., Mrini, M., Zehuaf, M., Chabaa, S. , Assarrar, M., and Mounir, H. 2014. How to manage cane in the field and factory following damaging freezes. International Sugar Journal. 116(1388) :526-531.
• Eggleston, G., DeLucca, A., Sklanka, S., Dalley, C., St. Cyr, E., Powell, R. 2015. Investigation of the stabilization and preservation of sweet sorghum juices. Industrial Crops and Products. 64:258-270.