Research Project: New Sustainable Processes, Preservation Technologies, and Product Concepts for Specialty Crops and Their Co-Products

Location: Healthy Processed Foods Research

2023 Annual Report

Objectives
The overall long-term objective of this project is to develop commercially-viable new sustainable processes, preservation technologies, and product concepts for specialty crops (fruits, vegetables, nuts, and legumes) and co-products of these crops. Specifically, during the next five years we will focus on the following objectives: Objective 1: Enable economical, input-efficient, and sustainable methods for processing and preservation of specialty crops while improving product quality and value. Subobjective 1A: Develop solar thermal alternatives for heat-intensive specialty crop processing unit operations. Subobjective 1B: Develop preservation strategies for reducing or eliminating the use of sulfites in dried fruit crops. Subobjective 1C: Develop more energy-efficient alternatives to conventional drying and freezing unit operations. Objective 2: Increase the commercial value of specialty crop co-products and difficult-to-market (No. 2 grade, for example) fruits/vegetables by processing into functional food ingredients. Objective 3: Enable value-added processing strategies for novel/emerging specialty crops, including protein sources from plants. Subobjective 3A: Develop new, protein-balanced ready-to-eat (RTE) pasta and snack foods with relevant functional attributes and acceptability made from legumes and specialty crops, through environmentally-friendly processing technologies. Subobjective 3B: Design innovative, delicious functional beverages and high-moisture foods from sustainable plant-based protein ingredients, using state-of-the art, minimally-thermal processing technologies to render products that have unique nutritional attributes and health benefits. Subobjective 3C: Leverage the unique advantages of 3D multilayer lithography and 3D cryo-lithography technology to form optimally-textured meat analogs from plant-based protein ingredients.

Approach
1A: Utilize solar thermal energy in evaporative concentration, blanching, and bin drying, with the goal of deriving up to 100% of the required heat from sunlight. For each system, the processing conditions will be established, an exergetic analysis performed, and the process designed and tested at pilot scale. Product quality will be measured and optimized alongside processing conditions. 1B: Reduce the sulfite content of dried fruits by 50% to 100% while maintaining organoleptic quality and nutrition equivalent to sulfited controls. For each fruit, various preservative ingredients and blanching pretreatments will be screened for individual and synergistic benefits on product quality metrics. Synergistic combinations will be applied to fruits that will be dried using various protocols. Optimal combinations of preservatives, blanching treatments, and drying protocols will be determined. 1C: Utilize infrared drying, isochoric freezing, and other promising technologies to obtain high-quality fruit and vegetable products and assess the energy efficiency of these technologies, with the rationale that these technologies will shorten processing time and operate at milder temperatures than conventional controls. 2A: Determine optimal operating conditions for processing raw co-products and low-grade products into shelf-stable ingredients, balancing throughput and product quality. Raw materials will be processed with pilot-scale unit operations such as drying, blanching, pasteurization, vacuum forming, casting, and freezing. 2B: Incorporate powdered specialty crop co-products with known antioxidant and antimicrobial activities into edible films and coatings applied to perishable foods via casting, dipping, and electrostatic spraying. Cast films will be characterized by scanning electronic microscopy, water vapor and oxygen permeability, mechanical properties, and various other quality metrics. 3A: Process legume pulses’ and specialty crops’ fractions (peels and hulls) into ready-to-eat, protein-balanced expanded extruded snacks and functional pasta. A co-rotating twin-screw extruder system will be used to process novel-formulated mixed flours into the new products. Processing variables will be studied to optimize product quality and mechanical/thermal energy input. 3B: Transform legume pulse protein concentrates, isolates, and specialty crops into novel healthy beverages and meat analogs. For beverages, legume pulse proteins and other fiber- and phytonutrient-rich specialty crop ingredients will be blended into nutritionally-balanced mixtures, solubilized, and processed by a high-pressure homogenizer. Meat analogs will be developed using high moisture protein fibration extrusion. 3C: Transform plant proteins into meat analogs with desirable functional and sensory properties using 3D multilayer lithography and 3D cryo-lithography. Various formulations of pulse- and legume-based proteins and other specialty crop-based additives will be tested. Processing parameters will include syringe temperature, extrusion speed, and nozzle temperature/diameter. Chemical, physical, rheological, and sensory properties of the 3D-printed products will be optimized.

Progress Report
Significant progress was made under Objective 1, by ARS researchers in Albany, California, by investigating the use of isochoric freezing as a non-thermal technology to enhance the safety and shelf life of pomegranate juice and carrot juice. The effects of isochoric freezing on the microbiological and physicochemical quality of fresh pomegranate juice and fresh carrot juice during storage were evaluated and compared to those obtained by using conventional pasteurization followed by refrigerated storage. The research shows the suitability of isochoric freezing to preserve the quality of the juices and maintain their microbiological stability. Relevant progress was made under Objective 3, by evaluating the influence of cross-linking order (before or after directional freezing) and freezing rates on the microstructure, rheological and textural properties of the 3D cryo-printed protein sample, with emphasis on the suitability of the product for a dysphagia diet. Temperature-controlled 3D cryo-printing led to the generation of microstructures that conferred texture to the 3D printed samples. The Temperature-controlled 3D cryo-printing technology can be also used for one-step process that combines manufacturing and freezing of foods. Also, under this Objective, the effect of high hydrostatic pressure (HPP) on structural and functional properties of isolated Kabuli chickpea proteins was investigated under different pressure levels and holding times. Protein’s structure, including amino acid profile, secondary structure, surface hydrophobicity, zeta potential, total free-sulfhydryl content, SDS-PAGE protein profile, and functional properties, including protein solubility, water and oil absorption capacities, emulsifying properties, and foaming capacity and stability were evaluated. Moreover, significant progress was made also under Sub-objective 3B, by developing an innovative healthy and delicious gluten-free and lactose-free plant-based beverage. The novel beverage was made from hydrolyzed pea and rice proteins, soluble fiber, and other natural food ingredients.

Accomplishments
1. New preservation technology extended the shelf-life of pomegranate arils, pomegranate juice and carrot juice. Extended shelf-life and low microbial load are main hurdles facing fruit juice producers. ARS researchers in Albany, California, discovered that isochoric freezing effectively increased the shelf-life of extracted pomegranate arils from 11 days in refrigeration to 33 days. Also, isochoric freezing reduced native microbial load below the limit of detection in pomegranate juice and in carrot juice. Furthermore, isochoric freezing inhibited microbial growth during storage which resulted in extended shelf-life when compared with pasteurized juice. The overall quality of the juice was better for the isochoric frozen juice than for the pasteurized juice. Isochoric freezing could be a beneficial alternative to conventional pasteurization.

2. 3D printed ground meat. ARS scientists in Albany, California, used temperature-controlled 3D cryoprinting (TCC) to provide texture to 3D printed ground meat. Texture is a major factor in the sensory evaluation of meat quality. TCC incorporates freezing to the conventional 3D printing technology, so that each deposited element during printing is frozen upon deposition. Directional freezing resulted in ice crystals growing forward as branches. Upon thawing, those ice crystals became directional pores with inserted beef material. This led to the generation of structures that conferred texture to the 3D printed ground meat. The technology can be used to provide texture to ground meat or meat analogues and provides patients experiencing swallowing difficulties with visually and texturally appealing nutritious foods.

3. Effect of high-pressure processing technology on the structure and function of chickpea protein isolates. The task proteins perform in food applications depends on their functionality. The efficacy of high hydrostatic pressure treatment on modifying the structure and function of chickpea protein isolates was demonstrated by ARS researchers in Albany, California. High pressure increased surface hydrophobicity, disulfide bonds and total sulfhydryl content. As a consequence, the protein’s functionality including water/oil absorption, emulsification and foaming capacities significantly increased, which plays a critical role in conveying desirable qualities and functionalities to food products. The study provides the baseline information for scientific community and food industry in improvement of functional properties of plant-based proteins through the use of high hydrostatic pressure technology.

Review Publications
Inzunza-Soto, M., Avena Bustillos, R.D., Thai, T.T., Roman, V., Whitehill, L.J., Tam, C.C., Rolston, M.R., Aleman-Hidalgo, D.M., Teran-Cabanillas, E., Yokoyama, W.H., McHugh, T.H. 2022. Health benefits of high protein and dietary fiber dry-fractioned brewery spent grain fines. ACS Food Science and Technology. 2(12):1870-1878. https://doi.org/10.1021/acsfoodscitech.2c00255.
Avena Bustillos, R.D., Klausner, N.M., Milczarek, R., Terán-Cabanillas, E., Alemán-Hidalgo, D.M., McHugh, T.H. 2022. Evaluation of predrying steps, cadmium, and pesticide residues on dried powders from romaine lettuce outer and heart leaves. ACS Food Science and Technology. 3(1). Article 41-49. https://doi.org/10.1021/acsfoodscitech.2c00234.
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.
Zhong, C., Feng, Y., Xu, Y. 2023. Production of fish analogues from plant proteins: Potential strategies, challenges, and outlook. Foods. 12(3). Article 614. https://doi.org/10.3390/foods12030614.
Du, Z., Ding, X., Xu, Y., Li, Y. 2023. UniDL4BioPep: A universal deep learning architecture for binary classification in peptide bioactivity. Briefings in Bioinformatics. 24(3). Article bbad135. https://doi.org/10.1093/bib/bbad135.
Lou, L., Bilbao-Sainz, C., Wood, D.F., Rubinsky, B. 2023. Temperature controlled cryoprinting of food for dysphagia patients. Innovative Food Science and Emerging Technologies. 86. Article 103362. https://doi.org/10.1016/j.ifset.2023.103362.
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.
Zhao, Y., Powell-Palm, M., Wang, J., Bilbao-Sainz, C., McHugh, T.H., Rubinsky, B. 2021. Analysis of global energy savings in the frozen food industry made possible by transitioning from conventional isobaric freezing to isochoric freezing. Renewable & Sustainable Energy Reviews. 151. Article 111621. https://doi.org/10.1016/j.rser.2021.111621.
Carvalho Ferreira, K., Correia Bento, J.A., Caliari, M., Zaczuk Bassinello, P., Berrios, J.D. 2021. Dry bean proteins: Extraction methods, functionality, and application in products for human consumption. Cereal Chemistry. 99(1):67-77. https://doi.org/10.1002/cche.10514.
Castaneda-Ruelas, G.M., Fajardo Lopez, A.J., Berrios, J.D., Mendoza-Lopez, I.A. 2022. Growth yield and health benefit of farm shrimp (Litopenaeus vannamei) fed in a pre-fattening phase with a diet based on wheat (Triticum sativum) and chickpea (Cicer arietinum) enriched with spirulina (Spirulina maxima). Veterinaria Mexico. 9. https://doi.org/10.22201/fmvz.24486760e.2022.966.
Berrios, J.D., Losso, J.N., Albertos, I. 2021. Extrusion processing of dry beans and pulses. In: Siddiq, M., Uebersax, M.A., editors. Dry Beans and Pulses: Production, processing, and nutrition. 2nd edition. West Sussex, UK: John Wiley & Sons Ltd. p. 225-246.
Zhao, H., Kim, Y., Avena Bustillos, R.D., Nitin, N., Wang, S.C. 2023. Characterization of California olive pomace fractions and their in vitro antioxidant and antimicrobial activities. LWT - Food Science and Technology. 180. Article 114677. https://doi.org/10.1016/j.lwt.2023.114677.