Progress 07/01/22 to 02/16/24

Outputs
Target Audience:During this reporting period, our efforts were focused on reaching out to two primary target audiences: potato farmers and the food industry. To effectively engage with these audiences, we collaborated with two key partners, the J.R. Simplot Company and Larta Institute. The J.R. Simplot Company, an agribusiness company headquartered in Boise, Idaho, played a crucial role in our outreach efforts. With major operations in the U.S., Canada, Mexico, Australia, Argentina, and China, they provide a diverse array of products and services to people worldwide. By partnering with them, we were able to establish connections with potato farmers who form a significant part of their customer base. Additionally, our collaboration with Larta Institute enabled us to extend our reach to the broader food industry. This partnership allowed us to tap into their expertise and networks within the industry, ensuring that our message reached relevant stakeholders. Furthermore, we worked closely with Jeff Carpenter from the Larta Institute, who assisted us in connecting with related companies in the targeted sectors. Jeff's extensive experience and knowledge in the field helped us establish valuable relationships with companies aligned with our technology and objectives. As part of our outreach strategy, we developed a comprehensive white paper specifically tailored to introduce our technology to the target audiences. This document served as a key resource for both potato farmers and food industry professionals, providing them with detailed information about our innovative solutions. Overall, our efforts during this reporting period successfully reached and engaged with potato farmers, as well as various stakeholders within the food industry, with the support of our strategic partnerships and targeted communication materials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hasan Rahat earned his Batchelor's degree in Chemical Engineering in Bangladesh. He started his Master's study in the Fall of 2022. His goal in life is to become a prominent researcher and pursue a career as a university teacher along with working on establishing a third-generation biofuel plant in Bangladesh. Benefiting from this project, he can continue to pursue his Master's and Ph.D. degrees for his professional development. This project provided training opportunities for Sarah in the operation of laboratory instruments and methods such as UV-Vis spectroscopy, HPLC, TS, VS and other parameters. Other training activities included studying process simulation, and techno-economic analysis (TEA) for Objective 2. There were weekly meetings with the mentor Dr. Liang Yu concerning this project. Also, meetings took place every week for the group to share ideas and progress. Students dedicated individual study time each week around this project, increasing professional development. How have the results been disseminated to communities of interest?We have identified and reached out to the three types of customers who are interested in our technology: downstream users, existing manufacturers, and potato farms. We have reached out to the representing companies and they showed interest in our technology. One of the companies seeking high-value conversion technology innovation to reuse potato peels in the future has also shown great interest in our technology. As interest in human health increases, the food industry and pharmaceutical companies have started looking for more effective products to meet the growing market demand and retain their competitive edge. Polyphenols are compounds that we get through certain plant-based foods. They are packed with antioxidants and potential health benefits. It's thought that polyphenols can improve or help treat digestion issues, weight management difficulties, diabetes, neurodegenerative disease, and cardiovascular diseases. Additionally, existing polyphenol producers will look for new ways to enhance their technology portfolio and reduce costs. The other type of potential customer is potato farms and other food or biomass farms such as apple pomace and grape pomace which typically have well-defined waste streams with relatively homogeneous compositions. We have initiated discussions with the companies which process potatoes at their respective facilities. More values are added downstream by others when the polyphenols are made into consumer products. If succeeds, our technology should be attractive to these facilities as potential customers. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective #1 Optimize the extraction process at a bench scale to gain performance certainty and obtain data for system integration and scale-up 1) Major activities completed / experiments conducted: The primary goal of this innovative process was to achieve dual objectives: reducing energy consumption and simplifying polyphenol purification. Notably, traditional methods relying on charcoal adsorption and separation were strategically omitted from our approach. To initiate the experimentation, a small-scale two-stage Soxhlet extraction process was developed. This initial phase served to conduct preliminary experiments for data collection, forming the basis for subsequent scaling-up and process design. Multiple Soxhlet extraction runs were conducted using ethanol and water to acquire preliminary data essential for establishing the process's mass balance. The process commenced with drying potato peel at a controlled 70?, a deliberately lower temperature aimed at preserving polyphenol integrity and avoiding thermal degradation or the generation of toxic byproducts. Following the drying process, the potato peel was finely ground into a dry powder using a food processor, achieving a particle size of approximately 2 mm. Subsequently, the peel underwent the first stage of Soxhlet extraction using anhydrous ethanol to extract polyphenols. The resulting solid residue underwent a second stage of Soxhlet extraction, this time utilizing water as the solvent to extract polysaccharides. The solid residue after both extraction stages demonstrated significant richness in protein and dietary fiber, presenting the potential for utilization as a dietary supplement or animal feed, contingent upon further refinement. Encouraged by the positive results obtained in the preliminary run, the process was upscaled to an intermediate level (10 L capacity) for larger lab-scale experiments. This involved obtaining a total of 1.23 kg of dry potato peel after freezing and drying the peel at 70? for 24 hours. The peel, with an average particle diameter of ~2 mm, was then processed for the first-stage ethanol extraction. In the first-stage ethanol extraction, 200-300 g (depending on the run) of potato peel powder was combined with 4 L of pure ethanol in a 5 L round-bottom flask. The mixture underwent stirring with a PID-controlled magnetic stirrer at 75?, just below the boiling point of ethanol (78?), for 6 hours (duration depending on the run). The resulting ethanol-polyphenol mixture underwent filtration to remove undissolved fine potato peel particles, followed by evaporation of ethanol to obtain condensed crude polyphenol liquid. The condensed liquid was further processed at 60? for 24 hours in a drying oven to remove remaining ethanol residue and produce solid polyphenol crude. For the second-stage water extraction, a similar procedure was followed, using water as the solvent at 95? (just below its boiling point of 100?) for 6 hours (duration depending on the run). The filtrated solid residue post-extraction, constituting nutrient-rich treated peel, underwent drying at 105? for 24 hours, rendering it suitable for use as animal feed. Post-water extraction, the condensed polysaccharide crude liquid underwent further drying at 80? for 24 hours to eliminate remaining water residue, resulting in solid polysaccharide crude ready for subsequent processing.. 2) Data collected; For the small-scale Soxhlet extraction stage, the dried sample (DW 98%) weighed around 5.5 g and 1 g during the ethanol and water extraction respectively. The extracted PP was 14.15 mg/g of dry peel with 15.55% purity. The extraction efficiency was found to be around 85%. The extraction of PP was about 7.1 mg/g of dried peel during the second stage of water extraction with 6.45% purity. Whereas the extraction of PS 21.2 mg/g of dried peel during the water extraction has 20.27% purity. During the 10 L intermediate-scale, stirred-reactor extraction, a total of 28.43 g crude polyphenol was extracted from 1164.7 g potato peel. The purity of polyphenol was around 29% having an extraction yield of 9.08 mg/g. Whereas 58.09 g crude polysaccharide was extracted from 540.3 g residual solids obtained after the first stage extraction. This crude contains 61% PS and 5.5% PP with a PS extraction yield of 78.51 mg/g of dried residual solid. 3) Summary statistics and discussion of results and In this study, the polyphenol content found in the ethanol extract was 14.15 GAE mg/g of dry potato peel (extraction efficiency is about 85%) during Soxhlet extraction. The polyphenol content found in the ethanol extract was 9.08 GAE mg/g of dry potato peel during the first stage ethanol extraction with the extraction efficiency of 57%. After the second stage water extraction, the total polyphenol content in water was 6.44 GAE mg/g of dry potato peel with an extraction efficiency of 40.5% totaling 97.5% of total polyphenol (most free-bound) from the peel achieving the target 90% lab-scale extraction yield. 4) Key outcomes or other accomplishments realized. The polyphenol extraction process excels in commercial applications by preserving polyphenol integrity through low-temperature extraction, ensuring food-grade quality and preventing toxic compound formation nearing 90% extraction of polyphenol. Valuable by-products, like polysaccharides with diverse biological activities and residual solids as animal feed are produced minimizing waste. Objective #2. Integrate the SeqHTL with product purification and conduct a techno-economic analysis of the complete system. 1) Major activities completed / experiments conducted; The goal of this task is to perform TEA based on the newly obtained results to guide the next step of commercialization efforts. This task includes two major activities: (1) complete TEA analysis (2) sensitivity analysis for different-sized systems. 2) Data collected; The TEA was conducted using ASPEN Plus software package. The Nth plant design was applied to the TEA model, assuming that mature technology and several plants employing the same technology have been established and operated. The installed cost of SeqHTL process was estimated using cost values estimated by Aspen Process Economic Analyzer. The total equipment and installation cost is calculated to be 1.72 MM $. The total operating cost is estimated to be 0.56 MM $/year. Whereas the total capital investment (TCI) was measured to estimated 3.53 MM $. The minimum selling price per kg of polyphenol was calculated $12.21 keeping NPV 0 for 30 years of plant life and IRR 10%. Subsequently, a sensitivity analysis was performed between the major 6 parameters feed tipping cost, co-product prices (polysaccharide and animal feed), operating cost, equipment cost, and internal rate of return (IRR) with ±30% change. The top three sensitive parameters in this process were found to be feed tipping cost, residual solid selling price, and polyphenol production rate. 3) Summary statistics and discussion of results and Different literature studies have shown pricing ranging from $8-15/kg for crude extracts to $33-3300/kg for processed extracts. Therefore, the minimum selling price for crude polyphenol in process $12.21 is well within the market price range $8-15/kg making the process economically viable and eligible for commercialization. The feed tipping cost was found to be the most sensitive among all the parameters. If only $10/ton is charged for acquiring potato peel waste from the generator, the MSP drops to $8.39 which is on the lower side of the market range ($8-15/kg). This analysis resulted in achieving the target goal of attaining the production cost target of $40/kg through TEA. 4) Key outcomes or other accomplishments realized. As a result, the new estimated price of the polyphenol crude product was $12.21/kg, which is very competitive in the market price range of $8-15/kg for crude extracts.

Publications

Progress 07/01/22 to 06/30/23

Outputs
Target Audience:During this reporting period, our efforts were focused on reaching out to two primary target audiences: potato farmers and the food industry. To effectively engage with these audiences, we collaborated with two key partners, the J.R. Simplot Company and Larta Institute. The J.R. Simplot Company, an agribusiness company headquartered in Boise, Idaho, played a crucial role in our outreach efforts. With major operations in the U.S., Canada, Mexico, Australia, Argentina, and China, they provide a diverse array of products and services to people worldwide. By partnering with them, we were able to establish connections with potato farmers who form a significant part of their customer base. Additionally, our collaboration with Larta Institute enabled us to extend our reach to the broader food industry. This partnership allowed us to tap into their expertise and networks within the industry, ensuring that our message reached relevant stakeholders. Furthermore, we worked closely with Jeff Carpenter from the Larta Institute, who assisted us in connecting with related companies in the targeted sectors. Jeff's extensive experience and knowledge in the field helped us establish valuable relationships with companies aligned with our technology and objectives. As part of our outreach strategy, we developed a comprehensive white paper specifically tailored to introduce our technology to the target audiences. This document served as a key resource for both potato farmers and food industry professionals, providing them with detailed information about our innovative solutions. Overall, our efforts during this reporting period successfully reached and engaged with potato farmers, as well as various stakeholders within the food industry, with the support of our strategic partnerships and targeted communication materials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hasan Rahat completed his Bachelor's degree in Chemical Engineering in Bangladesh before embarking on his Master's studies in the Fall of 2022. His ultimate aspiration is to establish himself as a prominent researcher and pursue a career as a university teacher. Additionally, he aims to contribute to the development of Bangladesh by establishing a third-generation biofuel plant. This ambitious project will not only facilitate his academic pursuits but also serve as a catalyst for his professional growth, enabling him to pursue Master's and Ph.D. degrees. The project has provided valuable training opportunities for Hasan Rahat and his colleague, Sarah, in the operation of various laboratory instruments and techniques, including UV-Vis spectroscopy, HPLC, TS, VS, and other relevant parameters. Furthermore, they have received training in process simulation and techno-economic analysis (TEA) to support Objective 2 of the project. Throughout the duration of the project, Hasan Rahat and Sarah have been actively engaged in weekly meetings with their mentor, Dr. Liang Yu, to discuss project progress and seek guidance. To foster a collaborative environment, regular group meetings have been organized where ideas and progress are shared among the team members. Hasan Rahat and Sarah have dedicated individual study time each week to deepen their understanding and enhance their professional development in line with the objectives of the project. These collective efforts contribute to their growth as researchers and prepare them for future academic and professional endeavors. How have the results been disseminated to communities of interest?During our market analysis, we have successfully identified and engaged with three distinct customer segments that have expressed keen interest in our technology: downstream users, existing manufacturers, and potato farms. Notably, representatives from these customer segments have shown strong interest in the innovative potential of our technology. In particular, a company seeking advanced conversion technology to repurpose potato peels has exhibited significant enthusiasm for our solution. With the growing focus on human health and wellness, the food industry and pharmaceutical companies are actively seeking more effective products to meet the expanding market demand and maintain their competitive edge. Polyphenols, compounds found in certain plant-based foods, have gained substantial attention due to their antioxidant properties and potential health benefits. Research suggests that polyphenols can improve digestion, aid in weight management, contribute to diabetes management, address neurodegenerative diseases, and promote cardiovascular health. Consequently, both the food industry and existing polyphenol producers are actively exploring ways to enhance their technology portfolios and reduce costs, making them ideal candidates for our technology. Additionally, we have identified another potential customer segment: potato farms and other food or biomass farms that generate waste streams with relatively homogeneous compositions, such as apple pomace and grape pomace. These farms present valuable opportunities for collaboration, as they possess well-defined waste streams that align with our technology's capabilities. We have initiated discussions with potato processing facilities and other relevant companies in this sector. It is important to note that the full value of polyphenols is realized when they are transformed into consumer products downstream. Therefore, the successful implementation of our technology would undoubtedly make it an attractive proposition for these facilities, as they would stand to benefit from the added value created by incorporating polyphenols into their product lines. Overall, our technology has generated significant interest from potential customers across different sectors, validating its appeal and potential impact in the market. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective #1 1) Major activities completed / experiments conducted: This study focuses on the development and optimization of the low-temperature multiple-stage sequential extraction system capable of extracting bioactive compounds e.g., polyphenols and polysaccharides from potato peel. The primary objective of this innovative process is to achieve two key outcomes: reducing energy consumption and simplifying the purification of polyphenols. To accomplish this, we have strategically eliminated the need for charcoal adsorption and separation, which are commonly employed in traditional purification methods. Through the laboratory-scale experiments, we are gathering valuable data that will contribute to the optimization and refinement of the process. This data will serve as a foundation for further research and development, ultimately leading to the design of an up-scaled process that can be implemented in real-world industrial settings. 2) Data collected; The analysis of polyphenol content in the potato peel was conducted as follows: Initially, the wet peels were ground using a mortar and pestle until a fine paste was obtained. The paste was then mixed with water, and only the homogeneous supernatant was utilized for the subsequent analysis. This ensured that the extract used for analysis was consistent and representative. The determination of polyphenol content was performed using the Folin Ciocalteu method. A calibration curve was constructed using gallic acid standards ranging from 0 to 10 mg/L, and the measurements were taken at a wavelength of 765 nm. The equation A = 0.0779x was used to establish the relationship between absorbance (A) and polyphenol concentration (x). Two replicates of the potato peel sample were taken, and the polyphenol content was determined for each replicate using the gallic acid standard. The results obtained were 9.53 mg/g and 11.85 mg/g of dry potato peel, respectively. These values fall within the range of polyphenol content previously reported in potato peels, which ranged from 0.3 to 27.4 mg/g in previous research. Calculating the average polyphenol content from the two replicates, we found that the potato peel had an average polyphenol content of 10±1 mg/g of dry potato peel. This corresponds to approximately 1±0.1% of the total weight of the potato peel. The extraction process of powdered potato peels using Soxhlet Extraction for 6 hours with anhydrous ethanol solution yielded the following results: A total of 1 g of powdered potato peels was subjected to the Soxhlet Extraction process using an anhydrous ethanol solution. After the extraction, the polyphenol content in the ethanol extract was determined to be 8.5±0.5 mg/g of dry potato peel. This indicates the concentration of polyphenols extracted from the potato peels. The extraction efficiency of the process was estimated to be approximately 85-95%. Additionally, the total solids present in the ethanol extract were measured to be 90.6 mg/g of dry potato peel. It is assumed that approximately 9% of these solids consist of polyphenols, while the remaining portion is predominantly composed of polysaccharides. These findings highlight the potential of the Soxhlet Extraction method using anhydrous ethanol solution as an efficient technique for extracting polyphenols from potato peels. The obtained results contribute to our understanding of the composition and extraction efficiency, supporting further optimization and utilization of potato peel extracts for various applications. 3) Summary statistics and discussion of results and Saldaña and Singh [1] reported the recovery of phenolic compounds from wet potato peel using different extraction methods. Their subcritical hydrothermal liquefaction (HTL) process at 180? for 30 minutes yielded 81.83 mg gallic acid equivalent (GAE)/100 g (equivalent to 4.1 mg/g of dry potato peel) of phenolic compounds. On the other hand, the methanol extraction conducted for 3 hours resulted in 46.59 mg GAE/100 g (equivalent to 2.3 mg/g of dry potato peel). These values were determined by assuming a typical water content of 80% in potato peels, falling within the range of 72-85% water content. Another study conducted by Brunton et al. [2, 3] utilized hydrothermal liquefaction (HTL) with lyophilized and milled potato peel samples to extract polyphenols. They achieved the highest polyphenol recovery yield of 5 mg GAE/g dry peel at 135? using 70% ethanol as the extraction solvent. In comparison, our study achieved a higher polyphenol content in the ethanol extract without the need for additional purification processes. The polyphenol content found in the ethanol extract was 8.5±0.5 mg GAE/g of dry potato peel, indicating a high yield of polyphenols. The extraction efficiency of our process was estimated to be approximately 85-95%. Notably, our method was performed at a much lower temperature compared to the aforementioned studies. [1] Singh, Pushp Pal, and Marleny DA Saldaña. "Subcritical water extraction of phenolic compounds from potato peel."Food Research International44.8 (2011): 2452-2458. [2] Rommi, Katariina, et al. "Potato peeling costreams as raw materials for biopolymer film preparation."Journal of Applied Polymer Science133.5 (2016). [3] Wijngaard, Hilde Henny, Mélanie Ballay, and Nigel Brunton. "The optimisation of extraction of antioxidants from potato peel by pressurised liquids."Food Chemistry133.4 (2012): 1123-1130. 4) Key outcomes or other accomplishments realized. The polyphenol extraction process offers several advantages, making it a suitable candidate for commercial applications. The polyphenol extraction process offers benefits such as enhanced polyphenol yield, production of food-grade polyphenols, utilization of the byproduct as animal feed, and the recycling and reuse of solvents. These advantages make the process well-suited for commercial applications, ensuring both quality and sustainability in the production of polyphenols. Objective #2. 1) Major activities completed / experiments conducted; When considering commercialization, the top indicator is its economics. The two-stage process is proven to achieve a higher extraction yield of polyphenols than the conventional method, which could lead to cost-effective production technology. In this section, a short but comprehensive description of process economics is presented, according to our previous work. Moreover, an updated techno-economic analysis (TEA) is provided based on the current experimental results. 2) Data collected; The standard TEA procedures include conducting mass and energy balance, estimating equipment and operating costs, and calculating the minimum product selling price. For this project, the entire extraction process contains SeqHTE, sugar precipitation, glycoalkaloid precipitation, and purification (filtration or adsorption). For every single unit, detailed mass and energy balance, as well as equipment and operating cost, were given in our work, based on previous experiments. 3) Summary statistics and discussion of results and According to the sensitivity result of the process, operating cost and polyphenol recovery are the two major contributors to the cost, besides financial terms, internal rate, or return. The new SeqHTE process coupled with dilute acid significantly improves the polyphenol recovery more than the one without acid addition. Based on the new experimental result, it can be roughly concluded that the polyphenol recovery yield is improved by 38%. Furthermore, a 50% saving on equipment cost and a 28% on operating cost was realized if drops in sugar separation and glycoalkaloid isolation unit. 4) Key outcomes or other accomplishments realized. As a result, the new estimated price of the concentrated purified product was $41/kg, which is very competitive in the market price range of $33-$3300/kg for puri?ed extracts.

Publications

Progress 07/01/22 to 02/15/23

Outputs
Target Audience:In this reporting period, the current target audiences are potato farmers and the food industry. We worked with the J.R. Simplot Company and Bird Dog Innovation Strategies to reach out to the target audiences. The J.R. Simplot Company is an agribusiness company headquartered in Boise, Idaho. Its major operations in the U.S., Canada, Mexico, Australia, Argentina, and China provide a diverse array of products and services to people around the world. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Hasan Rahat earned his Batchelor's degree in Chemical Engineering in Bangladesh. He started his Master's study in the Fall of 2022. His goal in life is to become a prominent researcher and pursue a career as a university teacher along with working on establishing a third-generation biofuel plant in Bangladesh. Benefiting from this project, he can continue to pursue his Master's and Ph.D. degrees for his professional development. This project provided training opportunities for Sarah in the operation of laboratory instruments and methods such as UV-Vis spectroscopy, HPLC, TS, VS and other parameters. Other training activities included studying process simulation, and techno-economic analysis (TEA) for Objective 2. There were weekly meetings with the mentor Dr. Liang Yu concerning this project. Also, meetings took place every week for the group to share ideas and progress. Students dedicated individual study time each week around this project, increasing professional development. How have the results been disseminated to communities of interest?We have identified and reached out to the three types of customers who are interested in our technology: downstream users, existing manufacturers, and potato farms. We have reached out to the representing companies and they showed interest in our technology. One of the companies seeking high-value conversion technology innovation to reuse potato peels in the future has also shown great interest in our technology. As interest in human health increases, the food industry and pharmaceutical companies have started looking for more effective products to meet the growing market demand and retain their competitive edge. Polyphenols are compounds that we get through certain plant-based foods. They are packed with antioxidants and potential health benefits. It's thought that polyphenols can improve or help treat digestion issues, weight management difficulties, diabetes, neurodegenerative disease, and cardiovascular diseases. Additionally, existing polyphenol producers will look for new ways to enhance their technology portfolio and reduce costs. The other type of potential customer is potato farms and other food or biomass farms such as apple pomace and grape pomace which typically have well-defined waste streams with relatively homogeneous compositions. We have initiated discussions with the companies which process potatoes at their respective facilities. More values are added downstream by others when the polyphenols are made into consumer products. If succeeds, our technology should be attractive to these facilities as potential customers. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective #1 1) Major activities completed / experiments conducted:We developed two designs to extract high-value polyphenols from raw potato peels in an environment-friendly and cost-effective manner. One is a Soxhlet-hydrothermal liquefaction (HTL) sequential process. The other is a two-stage sequential HTL (SeqHTL) process. Fresh Russet Burbank peels from a local food processing company - J. R. Simplot Company. The Russet Burbank cultivar had dark brown skins with 89 wt% moisture content. No further size-reduction process was performed before the extraction process.For the Soxhlet-HTL process, water is used as an extraction solvent in the first stage. Around 30-35 g of fresh peels were loaded into a Soxhlet extractor. 250-330 mL extraction solvent was used in the experiment. The extraction time ranged from 2 to 4 h. The fresh solvent for each extraction period enhances the mass transfer by increasing the concentration gradient driving force. Organic co-solvent (ethanol) can be added to lower the boiling point of the solvent to prevent the thermal degradation of polyphenols extracted and increase extraction efficiency for organic compounds. Extraction time and temperature and different organic solvents are the process parameters.After the completion of extraction, the solid was collected and washed and filtered. The extraction solvent with combined filtrate was collected for further analysis. For the SeqHTL process, around 30-40 g of fresh peels were loaded into a mini-batch reactor with the addition of a certain amount of acetic acid. Following similar procedures, the reaction was carried out at a temperature range from 150 to 170 oCin a sand bath. Parameters were selected based on preliminary trials. Compounds with -OH sidechains are preferentially recovered at ~170 oC. After product separation as previously mentioned, the resulting solid portion was loaded into the sand bath reactor to undergo the second stage HTL reaction (200 oC) without acid addition. Total polyphenol and polysaccharide content was analyzed for the aqueous extract from each stage. To further concentrate and purify the polyphenol extract obtained from a two-stage extraction process, a certain amount of polyphenol extract was mixed with charcoal as an adsorbent. The charcoal was thoroughly washed and dried before use. The charcoal loading was set at 15 mL extract /g charcoal. Then, the mixture was shaken for 35 h to perform the extraction process. After that, the solid was collected via a filter and remixed with water to leach the unbound substances, for instance, sugars. The solid was gained after 10 h shaking and subsequent filtration. Finally, the resulting solid was combined with ethanol for polyphenol extraction and shaking for 12 h. Once filtered, the liquid phase was collected and evaporated to remove ethanol. 2) Data collected: polyphenol and polysaccharide yields are collected forDesign 1 and 2, respectively. The followings are examples. Design 1. Soxhlet-HTL process Case1: First-stage (Soxhlet),Conditions (Water, 330 mL;4 h; 100oC),Sugar yield (wt.%) (17.0),Polyphenol yield, mg/g (24.1);Second-stage (HTL),Conditions (200oC; 15 min),Sugar yield(1.9),Polyphenol yield (25.8) Case 2:First-stage (Soxhlet: Water, 250 mL;2 h; 100oC),Sugar yield(23.0),Polyphenol yield (19.0);Second-stage (HTL: 200oC; 15 min),Sugar yield (0),Polyphenol yield (28.8) Case 3:First-stage (Soxhlet: Water: Ethanol, 300:30 mL;4 h; 94oC),Sugar yield (31.0),Polyphenol yield (26.3);Second-stage (HTL: 200oC; 15 min),Sugar yield (0),Polyphenol yield (30.3) Design 2. SeqHTL process Case1:First-stage (HTL: 150oC; 15 min; Acid: 0.9 M),Sugar yield (8.5),Polyphenol yield (10.7);Second-stage (HTL: 200oC; 15 min),Sugar yield(0),Polyphenol yield (24.9) Case 2:First-stage (HTL: 170oC; 15 min; Acid: 0.9 M),Sugar yield (7.4),Polyphenol yield (16.0); Second-stage (HTL: 200oC; 15 min),Sugar yield (1.3),Polyphenol yield (28.0) 3) Summary statistics and discussion of results:The Soxhlet-HTL process offers recovery of polyphenols and polysaccharides up to 56.6 mg/ g dry peel and 31 wt.%, respectively. The SeqHTL process is capable of recovering polyphenols and polysaccharides up to 44.0 mg/ g dry peel and 7 wt.%, respectively. Although the optimal polyphenol recovery from SeqHTL is lower than that of Soxhlet-HTL, it avoids using an organic solvent, requires less energy input as there is no need to evaporate solvent for recycling, has less reaction time, and generates a higher concentration of polyphenol extracts. The performance of the batch adsorption test at a small scale approved the concept, however, the yield was low, owing to the less charcoal loaded in the centrifuge tube. The next step is a continuous adsorption process based on experience. A total of 1.8 L of polyphenol extract was treated with 160 g charcoal to produce the final purified product of 3.26 g. 4) Key outcomes or other accomplishments realized:Two designs are considered: one is a Soxhlet-hydrothermal liquefaction (HTL) sequential process; another is a two-stage sequential HTL (SeqHTL) process. For the Soxhlet-HTL process, the polyphenol recovery ranged from 19 to 28 mg/g for the first stage and 14 to 30 mg/g for the second stage. For the SeqHTL process, the polyphenol recovery ranged from 8 to 16 mg/g for the first stage and 24 to 28 mg/g for the second stage. As a result, the two-stage extraction process enables the fractionation of potato peels to produce different types of polyphenols. The enhanced mass and heat transfer of the process promotes recovery and leads to a low-cost operation manner. Objective #2 1) Major activities completed / experiments conducted: The two-stage process is proven to achieve a higher extraction yield of polyphenols than the conventional method, which could lead to cost-effective production technology. In this section, a short but comprehensive description of process economics is presented, according to our previous work. Moreover, an updated techno-economic analysis (TEA) is provided based on the current experimental results. 2) Data collected:The standard TEA procedures include conducting mass and energy balance, estimating equipment and operating costs, and calculating the minimum product selling price. For this project, the entire extraction process contains SeqHTE, sugar precipitation, glycoalkaloid precipitation, and purification (filtration or adsorption). For every single unit, detailed mass and energy balance as well as equipment and operating cost were given in our work, based on previous experiments. 3) Summary statistics and discussion of results:From the total capital investment (TCI) result, SeqHTE cost share is relatively small compared with the sugar separation and purification process. A similar trend was also observed for the cost of manufacture (COM) result, where the adsorption method has an extraordinarily high cost than other processes. Since the new design excludes sugar separation and glycoalkaloid isolation, a great amount of equipment cost can be saved when choosing SeqHTE plus adsorption alone. According to the sensitivity result of the process, operating cost and polyphenol recovery are the two major contributors to the cost, besides financial terms, internal rate, or return. The new SeqHTE process coupled with dilute acid significantly improves the polyphenol recovery more than the one without acid addition. Based on the new experimental result, it can be roughly concluded that the polyphenol recovery yield is improved by 38%. Furthermore, a 50% saving on equipment cost and a 28% on operating cost was realized if drops in sugar separation and glycoalkaloid isolation unit. 4) Key outcomes or other accomplishments realized:As a result, the new estimated price of the concentrated purified product was $41/kg, which is very competitive in the market price range of $33-$3300/kg for purified extracts.

Publications