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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Research Project #439532

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

Location: Healthy Processed Foods Research

2021 Annual Report

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.

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
This is the first progress report for project 2030-41000-069-00D, which started in December 2020 and continues research from expired project 2030-41000-066-00D. For additional information, see the expired project’s report. Due to pandemic-related closure of the laboratory and pilot plant during fiscal year (FY) 2021 and the continuation of a critical vacancy in the project team, very limited progress was made toward Objectives 1 and 2. Literature reviews and experiment planning were conducted for the solar thermal energy project, but no physical experiments were performed. For sulfite reduction in dried fruits, various preservative ingredients, blanching pretreatments, and drying protocols were identified from the literature and mixture experiments were designed. The outer leaves of Romaine lettuce were identified as a co-product that could be processed into a shelf-stable ingredient, and preliminary experiments were performed to determine nutritional quality changes during drying. Considerable progress was made under Objective 3, by identifying novel ingredients from specialty crops and evaluating their performance and production using high temperature and cold extrusion for the production of expanded snacks and pasta products with acceptable flavor, taste, appearance, shelf life, and overall nutritional and functional properties. Also, progress was made in designing innovative, tasty, functional beverages based on legume pulse protein concentrates and isolates and special food ingredients rich in dietary fiber. Under Sub-objective 3A, a functional pasta (spaghetti) was developed using cold extrusion, from native and modified chayotextle (Sechium edule Sw.) flour. The proximal composition of the developed pasta was shown to have lower content of protein and fat but higher content of ash and resistant starch (RS). The results obtained in the study demonstrated the possibility for producing spaghetti containing up to 40% modified chayotextle flour, with acceptable quality and functional properties. Additionally, using high temperature extrusion processing, expanded gluten-free extruded snacks were developed from a mixture of tiger nut (TN, cyperus esculentus) and rice flours. Extrudates containing 10% TN showed the best overall texture profile. Viscoamylograph of the raw formulations showed that TN addition increased (p < 0.01) onset temperature and delayed peak viscosity. In the extruded flours, TN contributed to limit the starch degradation during extrusion. Moreover, TN addition enhanced the ash and protein content of the snacks and increased their total antioxidant activity. Under Sub-objective 3B, seven out of a total of 16 commercial beverages were selected based on their protein and dietary fiber content to be evaluated by their physical, chemical and nutritional value and compared to an improved beverage with higher protein and dietary fiber content. The protein content of the commercial beverages ranged between 3.38 and 9.23 grams per 100 milliliters and dietary fiber between 0.60 and 2.25 grams per 100 milliliters. The newly developed beverage contained up to 12 grams of protein per 100 milliliters and 9 grams of dietary fiber per 100 milliliters. Additionally, based on a visual stability index, the new beverage showed to be totally in solution, while the commercial beverages showed precipitation of their components. The viscosity, pH, and sensory properties of the novel beverages were found to be in acceptable ranges for this type of product. Visiting scientists from the Universities of AgroSup, LaSalle, and Reunion Island, France, collaborated with ARS researchers in the development of the new improved beverage with higher protein and dietary fiber content.

1. Chayotextle: a rich source of resistant starch (RS) in healthy pasta. Having low insulin sensitivity (insulin resistance, the responsiveness of the body’s cells to insulin) is believed to be a major risk factor for several serious diseases, including metabolic syndrome, Type 2 diabetes, obesity, heart disease and Alzheimer’s. Luckily, several studies have shown that resistant starch (RS) can improve insulin sensitivity. Also, RS is very effective at lowering blood sugar levels after meals. By improving insulin sensitivity and lowering blood sugar, resistant starch may help consumers avoid chronic disease and improve their quality of life. ARS researchers in Albany, California, developed a healthy pasta (spaghetti) from novel formulations containing nonconventional and underutilized native and modified chayotextle with 31-36 % RS. The study demonstrated the possibility for producing spaghetti containing up to 40% modified chayotextle, with acceptable quality and functional properties. The healthy pasta could provide a healthy alternative to commercial pasta (which has a negligible content of RS), for people suffering from low insulin sensitivity and high blood sugar.

Review Publications
Cotapallapa-Sucapuca, M., Vega, E.N., Maieves, H.A., Berrios, J.D., Morales, P., Fernandez-Ruiz, V., Camera, M. 2021. Extrusion process as an alternative to improve pulses products consumption. A review. Foods. 10. Article 1096.
Kim, S., Lee, J., Kwon, K., Jang, Y., Kim, J., Yu, K., Lee, S., Friedman, M. 2021. A bioprocessed black rice bran glutathione-enriched yeast extract protects rats and mice against alcohol-induced hangovers. Food and Nutrition Sciences. 12:223-238.
Chavarria-Hernandez, S.M., Berrios, J.D., Pan, J., Alves, P.L., Palma-Rodriguez, H.M., Hernandez-Uribe, J.P., Aparicio-Saguilan, A., Vargas-Torres, A. 2021. Native and modified chayotextle flour effect on functional property and cooking quality of spaghetti. International Journal of Food Science and Technology.