Research Project: Zero Waste Agricultural Processing

Location: Bioproducts Research

2023 Annual Report

Objectives
Food processing losses can represent up to 40 percent of the initial harvest, resulting in significant environmental and economic costs. With stakeholders like the Almond Board of California committed to achieving zero waste, we aim to create viable bioproducts from agricultural byproducts, everything from field to table. The first objective is to add value to a low-value almond processing coproduct, the hulls, which are the bitter, but sugar-rich fruit of the almond tree, by: (1) creating a phenolic-rich sweetener for human consumption; (2) extracting sugar from almond hulls for use in bee diets during the winter, and (3) developing cost-effective carbon feedstock for fermentation that produces bioplastics and specialty chemicals. With a commercial partner we will optimize a novel fermentation process to convert food waste (including hulls) into a commercially-viable family of bioplastics specifically polyhydroxyalkanoates (PHA) using the latest techniques in biotechnology. Objective 1: Develop sustainable technologies toward “zero waste” production by converting food waste, byproducts and under-utilized biomass streams into marketable plastics, specialty chemicals, additives, and active agents. • Sub-objective 1A. Add value to almond hulls. • Sub-objective 1B. Convert food waste and under-valued byproduct streams into bioplastics]. • Sub-objective 1C. Convert pectin-rich citrus peel waste, sugar beet biomass, and almond hulls into aldaric acid and aldonate bioproducts. Objective 2 focuses on optimizing new uses for underutilized agricultural fibers. In collaboration with several commercial partners, we plan to scale up torrefaction (heating biomass to 200-300 'C), to convert tree nut shells and hemp residue into functional fillers that will improve commodity plastics. We also propose to convert underutilized polysaccharides like pectin, alginate, and xylan were isolated from enzyme conversion processes into industrially-relevant environmentally friendly diacids such as aldaric acid for use as solvents in homecare products. Our group has developed a wide array of enzymes to deconstruct plant cell walls. These enzymes will be used, via combinatorial enzymatic strategies and in vitro reaction schemes, to create “designer oligosaccharides” and green chemicals that meet specific marketable needs. Objective 2: Optimize end-use technology for underutilized agricultural fibers, including straw residue, bagasse, and grasses by developing commercially-viable chemicals and nanoparticles for novel applications including nanocomposites. • Sub-objective 2A. Apply thermochemical conversion technology to add value to tree nut shells and underutilized crop residues including hemp. • Sub-objective 2B. Convert biomass into designer oligosaccharides using combinatorial enzyme technology.

Approach
Objective 1: Develop sustainable technologies toward “zero waste” production by converting food waste, byproducts and under-utilized biomass streams into marketable plastics, specialty chemicals, additives, and active agents. Sub-objective 1A. Add value to almond hulls. Sub-objective 1B. Convert food waste and under-valued byproduct streams into bioplastics. Sub-objective 1C. Convert pectin-rich citrus peel waste, sugar beet biomass, and almond hulls into aldaric acid and aldonate bioproducts. Objective 2: Optimize end-use technology for underutilized agricultural fibers, including straw residue, bagasse, and grasses by developing commercially-viable chemicals and nanoparticles for novel applications including nanocomposites. Sub-objective 2A. Apply thermochemical conversion technology to add value to tree nut shells and underutilized crop residues including hemp. Sub-objective 2B. Convert biomass into designer oligosaccharides using combinatorial enzyme technology.

Progress Report
This report documents progress in Fiscal Year (FY) 2023 for project 2030-41000-068-000D, titled, “Zero Waste Agricultural Processing”. In support of Sub-objective 1A, ARS researchers in Albany, California, are examining ways to add value to almond co-products by using membrane filtration to separate phenolic compounds from almond hull sugars. Almond hull extracts contain sugars and phenolic compounds, both of which can be valuable commodities. Membrane filtration was successfully used to remove sugars from the permeate and tests are ongoing to evaluate and optimize the separation efficiency of the filtration process. Also, steam explosion was successfully used to reduce particle size of the almond hulls to improve extraction efficiency. The results from these studies can be used to improve the almond hull extraction process and provide different product streams for potential commercialization. In support of Sub-objective 1B, polyhydroxyalkanoate (PHA) polymers are being optimized for use in compostable adhesive formulations for price look up labels used on fruits and vegetables. New international standards have required these labels to be fully home compostable. ARS researchers in Albany, California, in collaboration with industrial partners, have developed several adhesive formulations that have similar properties to commercial adhesives. The researchers have tested these formulations on different fruits and found that they meet the requisite standards. These results will help U.S. exporters of fruits and vegetables meet the new international standards. In support of Sub-objective 2A, thermochemical treatments were used to produce activated carbon from tree nut shells for removal of pollutants from wastewater. Almond and walnut shells were pyrolyzed and physically activated to produce activated carbon with specific pore size distributions and surface areas. Methylene blue was used as the model contaminant. ARS researchers in Albany, California, found that pore size played a more important role in adsorbing contaminants than total surface area. The researchers are also working with a commercial partner to use the activated carbon for removal of other pollutants. Also, pyrolyzed walnut shells were incorporated as fillers into gluten-based foams to produce foams that are derived from fully renewable resources. ARS researchers in Albany, California, found that the shells could be added to the foams without compromising the foam’s mechanical properties. These results provided the almond and walnut industries with information about alternate markets for their by-products. In support of Sub-objective 2B, the combinatorial enzyme approach was used to digest insoluble wheat arabinoxylan to produce oligosaccharides with anti-microbial properties. ARS researchers in Albany, California, first used sets of enzymes to produce libraries of oligosaccharides and then fractionated the oligosaccharides to isolate bioactive species. One isolated oligosaccharide was shown to suppress the growth of E. Coli over 48 hours. This active species may be useful as a new source of high-value preservative. The results from this study demonstrated the practical applications of the combinatorial enzyme approach to produce potentially high-value, novel bioactive compounds.

Accomplishments
1. Development of home compostable adhesives for produce labels. U.S. agricultural exports worth millions of dollars are at risk because several countries/regions led by France, Flanders, and New Zealand, have enacted legislation that will require all price look up labels on produce to be certified home compostable. ARS researchers in Albany, California, in collaboration with industrial partners, have developed a food-safe, compostable adhesive formulation that has solved a key coating issue of uneven spreading on the back of the labels. This formulation has been tested on a variety of produce and has met the requisite standards. The additive that was identified to solve the coating issue will be submitted in an invention disclosure. The results of this research will help American exporters of fruits and vegetables meet the more stringent international standards.

Review Publications
Wong, D., Batt Throne, S.B. 2022. Cloning of an a-L-arabinofuranosidase and characterization of its action on mono- and di-substituted xylopyranosyl units. Advances in Enzyme Research. 10(4):75-82. https://doi.org/10.4236/aer.2022.104005.
Wong, D., Batt Throne, S.B., Orts, W.J. 2023. Combinatorial enzyme approach to convert wheat insoluble arabinoxylan to bioactive oligosaccharides. BioResources. 11(1):1-10. https://doi.org/10.4236/aer.2023.111001.
Wu, P., Chen, L., Chen, M., Chiou, B., Xu, F., Liu, F., Zhong, F. 2023. Use of sodium alginate coatings to improve bioavailability of liposomes containing DPP-IV inhibitory collagen peptides. Food Chemistry. 414. Article 135685. https://doi.org/10.1016/j.foodchem.2023.135685.
Patterson, G.D., Orts, W.J., McManus, J.D., Hsieh, Y. 2022. Cellulose and lignocellulose nanofibrils and amphiphilic and wet-resilient aerogels with concurrent sugar extraction from almond hulls. ACS Agricultural Science and Technology. 3(1):140-151. https://doi.org/10.1021/acsagscitech.2c00264.
Liu, F., Yu, C., Guo, S., Chiou, B., Jia, M., Xu, F., Chen, M., Zhong, F. 2023. Extending shelf life of chilled pork meat by cinnamaldehyde nano emulsion at non-contact mode. Journal of Food Packaging and Shelf Life. 37. Article 101067. https://doi.org/10.1016/j.fpsl.2023.101067.
Liu, F., Zhu, K., Ma, Y., Yu, Z., Chiou, B., Jia, M., Chen, M., Zhong, F. 2023. Collagen films with improved wet state mechanical properties by mineralization. Food Hydrocolloids. 139. Article 108579. https://doi.org/10.1016/j.foodhyd.2023.108579.
Kuai, L., Liu, F., Chiou, B., Avena Bustillos, R.D., McHugh, T.H., Zhong, F. 2021. Controlled release of antioxidants from active food packaging: A review. Food Hydrocolloids. 120. Article 106992. https://doi.org/10.1016/j.foodhyd.2021.106992.
Vega-Galvez, A., Uribe, E., Pasten, A., Vega, M., Poblete, J., Bilbao-Sainz, C., Chiou, B. 2022. Low-temperature vacuum drying as novel process to improve papaya (Vasconcellea pubescens) nutritional-functional properties. Future Foods. 5. Article 100117. https://doi.org/10.1016/j.fufo.2022.100117.
Song, X., Chiou, B., Xia, Y., Chen, M., Liu, F., Zhong, F. 2021. The improvement of texture properties and storage stability for kappa carrageenan in developing vegan gummy candies. Journal of the Science of Food and Agriculture. 102(9):3693-3702. https://doi.org/10.1002/jsfa.11716.
Yin, M., Yuan, Y., Chen, M., Liu, F., Saqib, M., Chiou, B., Zhong, F. 2022. The dual effect of shellac on survival of spray-dried Lactobacillus rhamnosus GG microcapsules. Food Chemistry. 389. Article 132999. https://doi.org/10.1016/j.foodchem.2022.132999.
Xue, J., Liu, K., Chang, W., Chiou, B., Chen, M., Liu, F. 2022. Regulating the physicochemical properties of chitosan films through concentration and neutralization. Foods. 11(11). Article 1657. https://doi.org/10.3390/foods11111657.
Bilbao-Sainz, C., Chiou, B., Takeoka, G.R., Williams, T.G., Wood, D.F., Powell-Palm, M., Rubinsky, B., McHugh, T.H. 2022. Novel isochoric impregnation to develop high-quality and nutritionally fortified plant materials (apples and sweet potatoes). Journal of Food Science. 87(11):4796-4807. https://doi.org/10.1111/1750-3841.16332.
Bilbao-Sainz, C., Chiou, B., Takeoka, G.R., Williams, T.G., Wood, D.F., Powell-Palm, M., Rubinsky, B., McHugh, T.H. 2022. Novel isochoric cold storage with isochoric impregnation to improve postharvest quality of sweet cherry. ACS Food Science and Technology. 2(10):1558-1564. https://doi.org/10.1021/acsfoodscitech.2c00194.
Bilbao-Sainz, C., Chiou, B., Takeoka, G.R., Williams, T.G., Wood, D.F., Powell-Palm, M., Rubinsky, B., Wu, V.C., McHugh, T.H. 2022. Isochoric freezing and isochoric supercooling as innovative postharvest technologies for pomegranate preservation. Postharvest Biology and Technology. 194. Article 112072. https://doi.org/10.1016/j.postharvbio.2022.112072.
Liu, H., Chiou, B., Ma, Y., Corke, H., Liu, F. 2022. Reducing synthetic colorants release from alginate-based liquid-core beads with a zein shell. Food Chemistry. 384. Article 132493. https://doi.org/10.1016/j.foodchem.2022.132493.
Patterson, G.D., McManus, J.D., Orts, W.J., Hsieh, Y. 2023. Protonation of surface carboxyls on rice straw cellulose nanofibrils: Effect on the aerogel structure, modulus, strength, and wet resiliency. Biomacromolecules. 24(5):2052-2062. https://doi.org/10.1021/acs.biomac.2c01478.
Glenn, G.M., Orts, W.J., Klamczynski, A.P., Shogren, R., Hart-Cooper, W.M., Wood, D.F., Lee, C.C., Chiou, B. 2023. Compression molded cellulose fiber foams. Cellulose. 30:3489-3503. https://doi.org/10.1007/s10570-023-05111-0.
McCaffrey, Z., Cal, A., Torres, L.F., Chiou, B., Wood, D.F., Williams, T.G., Orts, W.J. 2022. Polyhydroxybutyrate rice hull and torrefied rice hull biocomposites. Polymers. 14(18). Article 3882. https://doi.org/10.3390/polym14183882.
Torres, L.F., McCaffrey, Z., Williams, T.G., Wood, D.F., Orts, W.J., McMahan, C.M. 2023. Evidence of silane coupling in torrefied agro-industrial residue-filled poly(styrene-co-butadiene) rubber compounds. Journal of Applied Polymer Science. 140(12). Article e53646. https://doi.org/10.1002/app.53646.