Progress 12/09/10 to 07/27/15
Outputs
Progress Report Objectives (from AD-416): 1. Develop green and scalable integrated processes which improve production economics to obtain modified pectins, ethanol or other biofuels, and other co-products such as limonene and flavonoids from citrus process waste streams. 2. Develop new commercially viable industrial bioproducts made from pectin. a) Enzymatic modification of citrus pectin nanostructure to tailor functionality. b) Determine ion exchange properties of enzyme modified pectin and peel particles. c) Determine rheological and water holding properties of chemically modified pectin and peel particles. Approach (from AD-416): Commercial success for development and recovery of byproducts from citrus waste streams depends on the ability to economically recover sufficient quantities to meet market demands, favorable recovery costs and market value. Integration of processes to separate and recover limonene, fermentable sugars, pectin and other polysaccharides, flavonoids and other components to produce multiple high value co-products will be investigated. Recovery of pectin or modified pectin along with other polysaccharides after water extraction of fermentable sugars will be investigated for utilization in industrial applications and integrated with a steam stripping treatment for recovery of volatile terpenes. Hydrolysis of citrus peel waste utilizing commercial enzyme products and subsequent fermentation of released sugars will be evaluated for efficacy in liquefaction, conversion of cellulose to glucose, ethanol production, and cost. This will be compared to extraction, concentration and utilization of isolated sugar and pectin/polysaccharide fractions. Separation, concentration and recovery schemes to separate fermentable sugars from non-fermentable components will include residue hydrolysis, use of ion-exchange and absorbent resins, ultrafiltration, nanofiltration, reverse osmosis, water/solvent extractions and selective precipitation. Mass balances and extraction efficiencies will be determined for major byproduct components Pectin is a major component of citrus peel with extensive functionality and the degree of methylesterification has a very strong influence on functionality. Techniques to reliably produce novel, non-random patterns of methylesterification in pectin molecules and accurately characterize their distribution will be investigated. Fractions containing pectin or other polysaccharides from citrus processing waste will be characterized for macromolecular and nanostructural properties. They will then be treated with pectin modifying enzymes at varying pH, temperature, and salt concentrations and the resulting changes in functionality and nanostructure determined. Chemical modifications will be performed using nucleophilic reagents to modify functionality alone or in combination with enzymatic treatments. Materials generated will be tested for biosorption properties as amorphous powdered materials and after conversion via chemical crosslinking. In addition, water holding capacity, viscosity, and other rheological functional properties such as yield point will be determined along with changes in fragmentation size, molecular weight distribution, degree of polymerization, degree of substitution of added groups, as well as thermal and pH tolerance. Materials with appropriate properties will then be tested in applications such as drilling fluids, dry strength additives for paper, cement additives, and absorbents for spill applications. The economics of producing newly developed by-products will be evaluated and compared with those products currently utilized for targeted applications. Economic information will include raw materials, consumable, and energy costs, fixed capitol investment cost, and a breakdown of operating and capital cost estimates. During the life of the project continued progress was made on all objectives. Objective 1. Citrus peel contains a significant quantity of fermentable sugars. A patent for pretreatment of citrus processing waste to produce fuel ethanol was granted. New commercially available enzymes were evaluated for hydrolysis of cellulose in citrus juice processing biomass. These enzymes lowered the cost of ethanol production from citrus processing biomass by $0.50/gallon produced. Since citrus processing biomass also contains a large amount (up to 20-30%) of the highly functional pectin polysaccharide, methods were explored to preserve it prior to enzymatic hydrolysis which destroys itS structure. Release of pectic hydrocolloids from citrus processing biomass in a batch process was demonstrated and the pectic hydrocolloids were structurally characterized. Concurrently, relocation of the laboratory staff and equipment was accomplished requiring considerable planning and time. All pilot scale and analytical equipment was relocated to a new facility in Ft. Pierce, FL and tested for satisfactory operation. Subsequently it was demonstrated that pressing of citrus processing biomass could produce a 5- 6% sugar solution which could be concentrated by a non-thermal reverse osmosis process for use as a fermentation substrate. With correct pretreatment of citrus processing waste and the sugar extracts obtained, no fouling of the reverse osmosis membrane was encountered and concentration of the sugar extracts by reverse osmosis was found to be much more economical than using thermal means. Remaining residues contained the pectic materials that were suitable for extraction. The feasibility of using a continuous steam explosion process on citrus processing biomass for the release of pectic hydrocolloids was demonstrated. Recovery of phenolic compounds via water washing of steam exploded citrus processing biomass also was demonstrated. Objective 2. Pectin is a major, highly valued, functional component of citrus fruit peel. Pectin functionality is largely dependent on two types of structural domains, neutral and charged, within a pectin molecule. Their size, distribution and frequency can vary within a single molecule or population of molecules. The size, distribution and frequency of these domains can be modified by either chemical or enzymatic methods. In order to relate these structural parameters to functionality, analytical and statistical methods are required. Throughout the life of the project we increased our abilities to modify and characterize the nanostructure of both charged and neutral domains within pectin molecules as well as other biochemical properties related to functionality. Chemical, enzymatic and chromatographic methods to isolate and structurally characterize neutral, uncharged domains within pectin molecules were developed. Statistical methods to analyze these neutral, uncharged domains were also developed. A novel, commercially available pectin modifying enzyme was shown to be effective for manipulating citrus pectin structure and functionality, demonstrating a potential for use in functionalizing pectic material in citrus processing biomass for food or industrial applications. Using this and other non-commercial enzymes we are developing a predictive model for generating desired functionality within a population of pectin molecules. This will be useful when introducing functionality into pectin containing citrus processing biomass. The potential functionalization of citrus processing biomass via modification of the pectic material contained within it was also demonstrated using chemical methods. A patent application was filed for a novel chemical method that chelates cations present in citrus processing biomass enabling greater control for introducing functional properties. A Material Transfer Agreement has been initiated for the testing of pectic materials we produce from steam exploded citrus processing biomass for commercial applications. This project has been replace by new research project #6034-41000-017. 00D. Accomplishments 01 Continuous inline production of pectic fragments. An ARS researcher in Ft. Pierce, Florida has demonstrated the ability to release and functionalize pectic fragments in agricultural processing wastes. A total of 70%�80% of the pectic material contained within citrus fruit peel has been released. This highly functional hydrocolloid can be modified by enzymatic and chemical methods and either retained with the remaining biomass or isolated as a separate fraction. Development of this technology has the potential to significantly improve the value of citrus processing biomass through the production of a material capable of modifying the viscosity of water. 02 Recovery of phenolic compounds from waste citrus peel. An ARS researcher in Ft. Pierce, Florida has demonstrated that large amounts of phenolic compounds present in citrus juice processing biomass can be recovered from a water wash of waste peel following treatment with a continuous inline process that uses steam to reduce particle size and solubilize valuable biochemical components. Although citrus phenolics have been shown to possess varied healthful benefits and are incorporated into numerous dietary supplements and fortified products they are not sourced from the US citrus industry. Our demonstration that these compounds are readily available from steam exploded citrus peel creates the potential for them to be supplied from a domestic crop.
Impacts
(N/A)
Publications
- Cameron, R.G., Kim, Y., Galant, A.L., Luzio, G.A., Tzen, J. 2015. Pectin Homogalacturonans: Nanostructural Characterization of Methylesterified Domains. Food Hydrocolloids Journal. 47:184-190.
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Progress 10/01/13 to 09/30/14
Outputs
Progress Report Objectives (from AD-416): 1. Develop green and scalable integrated processes which improve production economics to obtain modified pectins, ethanol or other biofuels, and other co-products such as limonene and flavonoids from citrus process waste streams. 2. Develop new commercially viable industrial bioproducts made from pectin. a) Enzymatic modification of citrus pectin nanostructure to tailor functionality. b) Determine ion exchange properties of enzyme modified pectin and peel particles. c) Determine rheological and water holding properties of chemically modified pectin and peel particles. Approach (from AD-416): Commercial success for development and recovery of byproducts from citrus waste streams depends on the ability to economically recover sufficient quantities to meet market demands, favorable recovery costs and market value. Integration of processes to separate and recover limonene, fermentable sugars, pectin and other polysaccharides, flavonoids and other components to produce multiple high value co-products will be investigated. Recovery of pectin or modified pectin along with other polysaccharides after water extraction of fermentable sugars will be investigated for utilization in industrial applications and integrated with a steam stripping treatment for recovery of volatile terpenes. Hydrolysis of citrus peel waste utilizing commercial enzyme products and subsequent fermentation of released sugars will be evaluated for efficacy in liquefaction, conversion of cellulose to glucose, ethanol production, and cost. This will be compared to extraction, concentration and utilization of isolated sugar and pectin/polysaccharide fractions. Separation, concentration and recovery schemes to separate fermentable sugars from non-fermentable components will include residue hydrolysis, use of ion-exchange and absorbent resins, ultrafiltration, nanofiltration, reverse osmosis, water/solvent extractions and selective precipitation. Mass balances and extraction efficiencies will be determined for major byproduct components Pectin is a major component of citrus peel with extensive functionality and the degree of methylesterification has a very strong influence on functionality. Techniques to reliably produce novel, non-random patterns of methylesterification in pectin molecules and accurately characterize their distribution will be investigated. Fractions containing pectin or other polysaccharides from citrus processing waste will be characterized for macromolecular and nanostructural properties. They will then be treated with pectin modifying enzymes at varying pH, temperature, and salt concentrations and the resulting changes in functionality and nanostructure determined. Chemical modifications will be performed using nucleophilic reagents to modify functionality alone or in combination with enzymatic treatments. Materials generated will be tested for biosorption properties as amorphous powdered materials and after conversion via chemical crosslinking. In addition, water holding capacity, viscosity, and other rheological functional properties such as yield point will be determined along with changes in fragmentation size, molecular weight distribution, degree of polymerization, degree of substitution of added groups, as well as thermal and pH tolerance. Materials with appropriate properties will then be tested in applications such as drilling fluids, dry strength additives for paper, cement additives, and absorbents for spill applications. The economics of producing newly developed by-products will be evaluated and compared with those products currently utilized for targeted applications. Economic information will include raw materials, consumable, and energy costs, fixed capitol investment cost, and a breakdown of operating and capital cost estimates. During FY 14 considerable progress was made in Objectives 2a and 2c. We have increased our analytical abilities to characterize the nanostructure of pectin molecules (Objective 2a). Pectin is a major, high valued component of citrus fruit peel. During the last year we have targeted the neutral, uncharged domains of pectin molecules. We have developed methods to isolate neutral regions from charged domains of the same molecules and to determine their average size and numbers. Populations of pectin molecules are very heterogeneous so statistical methods to describe their functional domains on the nanoscale level are a must. The functional properties of pectin are determined by the size and distribution of both their charged and neutral domains. Depending on the milieu in which pectin is found both domains may contribute to the structural integrity of the system. The neutral domains are capable of different types of molecular interactions than charged domains and can participate in interactions with other non-charged molecules or similar domains in other pectin molecules. The summation of many of these types of molecular interactions can result in significant stability to a system. The charged domains are capable of being cross linked to other charged domains in other pectin molecules by metals such as calcium. Strong structural gels can be formed in this way. Possessing analytical tools and statistical methods to describe both domains in a population of molecules increases our ability to predict the population�s functional properties. We have also been successful in developing methods to modify the agricultural wastes resulting from citrus juice processing (fruit peel) using mechanical and chemical tools. We have been able to impart dramatically improved gelling properties to citrus fruit peel particles by altering the charge properties of the pectin contained within the citrus peel tissue (Objective 2c). By releasing the pectin from the peel particles and then enzymatically or chemically modifying pectin molecules to create charged domains, followed by drying and milling, we have been able to form very strong gel structures as determined by analytical techniques. We have explored both batch and continuous inline methods for functionalization of peel particles and have successfully demonstrated both techniques. Accomplishments 01 Continuous inline production of pectic fragments. An ARS researcher in Ft. Pierce, Florida has demonstrated the ability to release pectic fragments from agricultural processing wastes. Yields of 70%�80% of the pectic material contained within citrus fruit peel have been obtained. This highly functional hydrocolloid can be modified by enzymatic and chemical methods and either retained with the remaining tissue components or isolated as a separate fraction. 02 Descriptive statistics for neutral domains in pectin. An ARS researcher in Ft. Pierce, Florida has developed the technology to isolate and characterize the neutral domains within a pectin molecule. These domains are important structural components when certain molecular interactions dominate the forces controlling pectin containing structures. Statistical methods for their characterization may lead to a predictive tool for formulating desirable attributes related to texture and viscosity for commercial pectin products.
Impacts
(N/A)
Publications
- Savary, B.J., Vasu, P., Cameron, R.G., Mccollum, T.G., Nunez, A. 2013. Structural Characterization of the Thermally-Tolerant Pectin Methylesterase Purified from Citrus sinensis Fruit and Its Gene Sequence. Journal of Agricultural and Food Chemistry. 61:12711-12719.
- Kim, Y., Williams, M.A., Tzen, J.T., Luzio, G.A., Galant, A.L., Cameron, R. G. 2014. Characterization of Charged Functional Domains Introduced into a Modified Pectic Homogalacturonan by an Acidic Plant Pectin Methylesterase (Ficus awkeotsang Makino) and Modeling of Enzyme Mode of Action Food Hydrocolloids. Food Hydrocolloids Journal. 39:319-329.
- Galant, A.L., Luzio, G.A., Widmer, W.W., Cameron, R.G. 2014. Compositional and Structural Characterization of Pectic Material from Frozen Concentrated Orange Juice. Food Hydrocolloids Journal. 35:661-669.
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Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): 1. Develop green and scalable integrated processes which improve production economics to obtain modified pectins, ethanol or other biofuels, and other co-products such as limonene and flavonoids from citrus process waste streams. 2. Develop new commercially viable industrial bioproducts made from pectin. a) Enzymatic modification of citrus pectin nanostructure to tailor functionality. b) Determine ion exchange properties of enzyme modified pectin and peel particles. c) Determine rheological and water holding properties of chemically modified pectin and peel particles. Approach (from AD-416): Commercial success for development and recovery of byproducts from citrus waste streams depends on the ability to economically recover sufficient quantities to meet market demands, favorable recovery costs and market value. Integration of processes to separate and recover limonene, fermentable sugars, pectin and other polysaccharides, flavonoids and other components to produce multiple high value co-products will be investigated. Recovery of pectin or modified pectin along with other polysaccharides after water extraction of fermentable sugars will be investigated for utilization in industrial applications and integrated with a steam stripping treatment for recovery of volatile terpenes. Hydrolysis of citrus peel waste utilizing commercial enzyme products and subsequent fermentation of released sugars will be evaluated for efficacy in liquefaction, conversion of cellulose to glucose, ethanol production, and cost. This will be compared to extraction, concentration and utilization of isolated sugar and pectin/polysaccharide fractions. Separation, concentration and recovery schemes to separate fermentable sugars from non-fermentable components will include residue hydrolysis, use of ion-exchange and absorbent resins, ultrafiltration, nanofiltration, reverse osmosis, water/solvent extractions and selective precipitation. Mass balances and extraction efficiencies will be determined for major byproduct components Pectin is a major component of citrus peel with extensive functionality and the degree of methylesterification has a very strong influence on functionality. Techniques to reliably produce novel, non-random patterns of methylesterification in pectin molecules and accurately characterize their distribution will be investigated. Fractions containing pectin or other polysaccharides from citrus processing waste will be characterized for macromolecular and nanostructural properties. They will then be treated with pectin modifying enzymes at varying pH, temperature, and salt concentrations and the resulting changes in functionality and nanostructure determined. Chemical modifications will be performed using nucleophilic reagents to modify functionality alone or in combination with enzymatic treatments. Materials generated will be tested for biosorption properties as amorphous powdered materials and after conversion via chemical crosslinking. In addition, water holding capacity, viscosity, and other rheological functional properties such as yield point will be determined along with changes in fragmentation size, molecular weight distribution, degree of polymerization, degree of substitution of added groups, as well as thermal and pH tolerance. Materials with appropriate properties will then be tested in applications such as drilling fluids, dry strength additives for paper, cement additives, and absorbents for spill applications. The economics of producing newly developed by-products will be evaluated and compared with those products currently utilized for targeted applications. Economic information will include raw materials, consumable, and energy costs, fixed capitol investment cost, and a breakdown of operating and capital cost estimates. Citrus processing waste contains 8-10% sugars fermentable by conventional yeasts and after enzyme liquefaction and fermentation can yield 3.5 � 4. 5% ethanol. This is on the very low end of ethanol concentrations considered to be economically distillable and the enzymatic liquefaction process degrades the pectin in citrus waste limiting use. Water extraction of fermentable sugars to allow subsequent pectin extraction from the waste residue as an additional co-product yields sugar extracts which are dilute. Concentration by thermal means of either the dilute sugar extract prior to fermentation or the dilute ethanol stream produced after fermentation is not economical. In order to be able to obtain modified pectins and ethanol as outlined in objective 1, a reverse osmosis system for concentration of dilute sugar extracts from citrus prior to fermentation was tested. With correct pretreatment of citrus processing waste and the sugar extracts obtained, no fouling of the reverse osmosis membrane was encountered and concentration of the sugar extracts by reverse osmosis was found to be much more economical than using thermal means. The citrus residues left after extraction of sugars were also suitable for pectin extraction or modification. In the development of new commercially viable industrial bioproducts made from pectin, progress was made pertaining to value-added research into the polysaccharide structure and modification of citrus processing residues. Work was initiated on the functionalization of citrus peel via chemical and enzymatic modifications. Preliminary studies indicate that gelling and viscosity properties can be manipulated. Testing and data on enzymatic deesterification of citrus pectin suggest that only a subfraction of pectin molecules are modified and potential properties of pectin may not be fully realized without further improvements to enzymatic modification procedures or use of chemical deesterification. Fully deesterified pectins were produced chemically from peel waste under chelation conditions and shown to form stable gels useful for suspension applications.
Impacts
(N/A)
Publications
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Progress 10/01/11 to 09/30/12
Outputs
Progress Report Objectives (from AD-416): 1. Develop green and scalable integrated processes which improve production economics to obtain modified pectins, ethanol or other biofuels, and other co-products such as limonene and flavonoids from citrus process waste streams. 2. Develop new commercially viable industrial bioproducts made from pectin. a) Enzymatic modification of citrus pectin nanostructure to tailor functionality. b) Determine ion exchange properties of enzyme modified pectin and peel particles. c) Determine rheological and water holding properties of chemically modified pectin and peel particles. Approach (from AD-416): Commercial success for development and recovery of byproducts from citrus waste streams depends on the ability to economically recover sufficient quantities to meet market demands, favorable recovery costs and market value. Integration of processes to separate and recover limonene, fermentable sugars, pectin and other polysaccharides, flavonoids and other components to produce multiple high value co-products will be investigated. Recovery of pectin or modified pectin along with other polysaccharides after water extraction of fermentable sugars will be investigated for utilization in industrial applications and integrated with a steam stripping treatment for recovery of volatile terpenes. Hydrolysis of citrus peel waste utilizing commercial enzyme products and subsequent fermentation of released sugars will be evaluated for efficacy in liquefaction, conversion of cellulose to glucose, ethanol production, and cost. This will be compared to extraction, concentration and utilization of isolated sugar and pectin/polysaccharide fractions. Separation, concentration and recovery schemes to separate fermentable sugars from non-fermentable components will include residue hydrolysis, use of ion-exchange and absorbent resins, ultrafiltration, nanofiltration, reverse osmosis, water/solvent extractions and selective precipitation. Mass balances and extraction efficiencies will be determined for major byproduct components Pectin is a major component of citrus peel with extensive functionality and the degree of methylesterification has a very strong influence on functionality. Techniques to reliably produce novel, non-random patterns of methylesterification in pectin molecules and accurately characterize their distribution will be investigated. Fractions containing pectin or other polysaccharides from citrus processing waste will be characterized for macromolecular and nanostructural properties. They will then be treated with pectin modifying enzymes at varying pH, temperature, and salt concentrations and the resulting changes in functionality and nanostructure determined. Chemical modifications will be performed using nucleophilic reagents to modify functionality alone or in combination with enzymatic treatments. Materials generated will be tested for biosorption properties as amorphous powdered materials and after conversion via chemical crosslinking. In addition, water holding capacity, viscosity, and other rheological functional properties such as yield point will be determined along with changes in fragmentation size, molecular weight distribution, degree of polymerization, degree of substitution of added groups, as well as thermal and pH tolerance. Materials with appropriate properties will then be tested in applications such as drilling fluids, dry strength additives for paper, cement additives, and absorbents for spill applications. The economics of producing newly developed by-products will be evaluated and compared with those products currently utilized for targeted applications. Economic information will include raw materials, consumable, and energy costs, fixed capital investment cost, and a breakdown of operating and capital cost estimates. Objective 1: All pilot scale equipment (pretreatment system, fermentation tank, distillation tower, boiler, and associated control systems) and analytical equipment was moved, reinstalled, and tested to be in satisfactory working condition at the new Fort Pierce facility. Additionally, tests were performed on extraction and recovery of pectic fragments from citrus waste as a possible co-product with ethanol production. Effective extraction of pectin and/or pectic fragments significantly diluted fractions containing fermentable sugars and requires a concentration step of the sugar fraction prior to fermention to ethanol. Objective 2: Progress was made pertaining to value-added research into the polysaccharide structures of citrus byproducts. Pectin methylesterase present in a commercial papaya enzyme extract was used to demethylate a model pectin molecule. The resulting modifications to the pectin nanostructure have been characterized. The results indicate that reaction conditions (i.e., pH and enzyme/substrate ratios)affect the introduced nanostructural motifs. Accomplishments 01 A predictive model for the relationship between pectin nanostructure and rheological properties was developed. Pectin functionality is dependent on the distribution of charges along its polymeric backbone. Random versus ordered distribution affects its functionality and variations in the degree or order within the polymer chain also affect rheology. Pect charge distributions were modified using enzymes or chemical processes a technology was developed to statistically describe the nanostructural modifications introduced. Rheological testing of the engineered pectins enabled us to develop a predictive model relating the nanostructural parameters to rheological properties. This accomplishment has the potential to allow producers of hydrocolloids greater control over textu gel formation and viscosity of pectin in formulations targeted for industrial applications.
Impacts
(N/A)
Publications
- Milokva, V., Kamburova, K., Cameron, R.G., Radeva, T. 2011. Complexation of ferric oxide particles with pectins of ordered and random distribution of charged units. Biomacromolecules. 13:138-145.
- Grohmann, K., Cameron, R.G., Kim, Y., Widmer, W.W., Luzio, G.A. 2012. Extraction and recovery of pectic fragments from citrus processing waste for co-production with ethanol. Journal of Chemical Technology & Biotechnology. DOI: 10.1002/jctb.3859.
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Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) 1. Develop green and scalable integrated processes which improve production economics to obtain modified pectins, ethanol or other biofuels, and other co-products such as limonene and flavonoids from citrus process waste streams. 2. Develop new commercially viable industrial bioproducts made from pectin. a) Enzymatic modification of citrus pectin nanostructure to tailor functionality. b) Determine ion exchange properties of enzyme modified pectin and peel particles. c) Determine rheological and water holding properties of chemically modified pectin and peel particles. Approach (from AD-416) Commercial success for development and recovery of byproducts from citrus waste streams depends on the ability to economically recover sufficient quantities to meet market demands, favorable recovery costs and market value. Integration of processes to separate and recover limonene, fermentable sugars, pectin and other polysaccharides, flavonoids and other components to produce multiple high value co-products will be investigated. Recovery of pectin or modified pectin along with other polysaccharides after water extraction of fermentable sugars will be investigated for utilization in industrial applications and integrated with a steam stripping treatment for recovery of volatile terpenes. Hydrolysis of citrus peel waste utilizing commercial enzyme products and subsequent fermentation of released sugars will be evaluated for efficacy in liquefaction, conversion of cellulose to glucose, ethanol production, and cost. This will be compared to extraction, concentration and utilization of isolated sugar and pectin/polysaccharide fractions. Separation, concentration and recovery schemes to separate fermentable sugars from non-fermentable components will include residue hydrolysis, use of ion-exchange and absorbent resins, ultrafiltration, nanofiltration, reverse osmosis, water/solvent extractions and selective precipitation. Mass balances and extraction efficiencies will be determined for major byproduct components Pectin is a major component of citrus peel with extensive functionality and the degree of methylesterification has a very strong influence on functionality. Techniques to reliably produce novel, non-random patterns of methylesterification in pectin molecules and accurately characterize their distribution will be investigated. Fractions containing pectin or other polysaccharides from citrus processing waste will be characterized for macromolecular and nanostructural properties. They will then be treated with pectin modifying enzymes at varying pH, temperature, and salt concentrations and the resulting changes in functionality and nanostructure determined. Chemical modifications will be performed using nucleophilic reagents to modify functionality alone or in combination with enzymatic treatments. Materials generated will be tested for biosorption properties as amorphous powdered materials and after conversion via chemical crosslinking. In addition, water holding capacity, viscosity, and other rheological functional properties such as yield point will be determined along with changes in fragmentation size, molecular weight distribution, degree of polymerization, degree of substitution of added groups, as well as thermal and pH tolerance. Materials with appropriate properties will then be tested in applications such as drilling fluids, dry strength additives for paper, cement additives, and absorbents for spill applications. The economics of producing newly developed by-products will be evaluated and compared with those products currently utilized for targeted applications. Economic information will include raw materials, consumable, and energy costs, fixed capitol investment cost, and a breakdown of operating and capital cost estimates. A patent to pretreat of citrus processing waste to produce fuel ethanol was granted. Two new commercial cellulose degrading enzymes were tested for improvements on the simultaneous enzymatic hydrolysis and fermentation of citrus processing waste to liquify, convert available cellulose to fermentable sugars, and convert fermentable sugars to ethanol for use as a biofuel. Both enzymes are much less expensive than previously available food grade products and showed much higher activity to produce glucose which is easily fermentable from cellulose. One enzyme tested also was able to produce a relatively low viscosity fermented mixture and was much easier to strip the ethanol off than previous fermentation mixtures have viscosities over 10,000 centipoise. These new available enzymes lower the enzymes cost for citrus waste treatment to approximately $0.50/gallon ethanol produced. Multiple pressings of citrus processing waste with minimal water addition showed that greater than 80% of the soluble sugars could be removed from the nonsoluble residues, yielding a 5-6% sugar wash and residue that is suitable for pectin extraction. Non-thermal concentration of the water sugar wash is being pursued to overcome fouling issues in order to produce a 20-25% fermentable sugar substrate for improved ethanol production for use as a biofuel. A method for rapid pectin analysis for determining free acid groups based on conductivity. Determination of these functional groups is important for development of suspension aid products. Analyzed fractions from high temperature extraction of citrus peel for molecular weight and other important properties, which is important for understanding separation pectin fraction before peel fermentation takes place. It has been found that not all pectin is involved in the formation of gels. Preliminary testing and data suggests that only a subfraction of the pectin molecules are modified by enzymatic deesterification and that the potential properties of pectin may not be fully realized without further improvements to the enzymatic the modification procedure. This project replaced project 6621-41000-013-00D which was a bridging project for project 6621-41000-011-00D.
Impacts
(N/A)
Publications
- Widmer, W.W. 2011. Analysis of biomass sugars and galacturonic acid by gradient anion exchange chromatography and pulsed amperonmetric detection without post-column addition. Biotechnology Letters. 33:365-368.
- Cancalon, P.F., Barros, S.M., Haun, C., Widmer, W.W. 2011. Effect of maturity, processing, and storage on the furanocoumarin composition of grapefruit and grapefruit juice. Journal of Food Science. 76(4):C543-548.
- Widmer, W., Zhou, W., Grohmann, K. 2010. Pretreatment effects on orange processing waste for making ethanol by simultaneous saccharification and fermentation. Bioresource Technology. 101:5242-5249.
- Hanley, M.J., Cancalon, P., Widmer, W.W., Greenblatt, D.J. 2011. The effect of grapefruit juice on drug disposition. Expert Opinion on Drug Metabolism & Toxicology. 7(3):267-286.
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