Location: Functional Foods Research
2022 Annual Report
Objectives
Objective 1: Innovate processes to improve the properties of underutilized crops such as sorghum, millet, and hemp seed (SMHS), and their byproducts to enable increased commercial use.
•Sub-objective 1A: Enhance the health-promoting and commercially important functional properties of SMHS flours, fractions and byproducts by thermomechanical processing treatments alone or in combination to obtain new components and composites.
•Sub-objective 1B: Enhance the health-promoting and commercially important functional properties of SMHS flours, fractions and byproducts by chemical/enzymatic treatments alone or in combination with either thermomechanical processing.
•Sub-objective 1C: Enhance the health-promoting and commercially important functional properties of SMHS flours, fractions and byproducts by addition of other grain- or legume-based ingredients for functional composite formation, nutritionally complete diets, and flavor, texture, or structure improvement of food matrices.
Objective 2: Integrate the digestive health attributes of various SMHS components and their composites following innovative applications to improve process economics of food products and develop bioproduct ingredients using SMHS components.
•Sub-objective 2A: Develop food applications from SMHS components and conduct digestive health study.
•Sub-objective 2B: Develop non-food applications from SMHS components.
Approach
The dietary benefits of sorghum, millet, and hemp seed (SMHS) are well established and are increasingly recognized as valuable sources of protein, starch, fiber, antioxidants, and other nutrients. These crops are also drought resistant. They are, however, underutilized and used mainly for animal feed and biofuel production (sorghum) in the Unites States. The overall goal of this project plan is to convert these underutilized crops and their byproducts from milling and biofuel production into value-added food products and bio-products based upon their nutritional, physiochemical or chemical properties. There exist two primary challenges facing wider utilization of SMHS:1) consumption barrier that stems from characteristics of SMHS and perception; 2) byproducts of biofuel (sorghum) and milling of SMHS could be better utilized to defray production cost. We will focus on identifying the effects of synergistic thermomechanical and biological treatments on SMHS grains, flours, and fractions and developing processing strategy based upon understanding of SMHS component interactions and information of in vitro and in vivo digestive health studies to enhance the nutritional, structural and functional properties of SMHS based food products. The processed SMHS materials will be incorporated into standard food formulations with the aim of maximizing the content of SMHS-based ingredients with marketable sensory properties. Non-food applications will also be investigated based on physical and chemical properties of the end products. The outcomes of this research will expand domestic and international markets for SMHS crops and therefore contribute to the sustainability of US agriculture in the era of climate change.
Progress Report
Expanding food uses of sorghum, millet, and hemp seeds (SMHS) requires considerable innovative processing as SMHS contains either antinutritional components that reduce nutrition absorption or unpalatable flavors. The goal of the research during the current reporting period was to generate knowledge and technologies for preparing functional food ingredients with increased health benefits. The technologies developed in the lab and knowledge generated will enable the food industry to better incorporate SMHS materials into many existing food categories thus enhancing the demand and values of these crops. Consumers also benefit from the presence of these healthful food products in the marketplace.
Under Objective 1: We conducted research on protein modifications. Proteins from SMHS have good nutritional profiles, and they provide good sources of gluten-free proteins. However, the structures of these grains limit their applications in food products for several reasons: protein concentration, protein digestibility, and compatibility with other food ingredients in food products due to its material performing and sensory properties. This year, we have modified the structure of hempseed protein so that we can improve its gelling properties and water and oil-holding capacities for several food applications. Defatted hempseed meal was obtained after oil was removed, and a hempseed meal concentrate has been isolated. We developed gels formed from the hempseed protein concentrate. We measured the rheological properties of the gels to use to obtain a baseline for comparison with gels made from modified hemp seed proteins. Thermomechanical processes such as steam jet cooking and polytron were applied to induce structural changes in the flours of SMHS and physicochemical and sensory properties of significant importance to the food industry were measured. Our preliminary data analysis indicates the property change from processing SMHS grains enables SMHS fractions to be used in existing formulation of a wide range of baked goods including cookies, noodles, cakes, and gluten-free breads. Research conducted on SMHS grains, which have special nutritional and gluten-free qualities compared to common ordinary grains such as wheat, rice, or corn, has demonstrated the potential role of these grains as functional food ingredients without adverse sensory profile or flavors/texture. Our studies have the potential to create healthful alternative ingredients for gluten intolerant consumers but also for providing food products that deliver improved health benefits for commercial markets. Research was also conducted by adding healthy oil or pulses to these processed fractions or flours that can enhance nutritional completion of existing foods for consumers and are suitable for commercial scale production due to modified physicochemical properties of SMHS ingredients by the technologies developed by ARS.
Under Objective 2: We continue to conduct research on applications of newly developed fractions and flours of various underutilized grains in various food categories. The lack of food uses of SMHS in America is mainly due to the palatable issue and digestibility (and perception for some people). In order to overcome this barrier to consumption, processing technologies must be developed to eliminate contributing factors of unappetizing taste and texture. Thermomechanical and other processes have been used to treat fractions of the grains or flours. The fractions or flours after processing (thermomechanical and/or fermentation) were then used as healthy replacements for formulations of potential commercial food products (for example, baked products); in many cases we blended them with other nutritionally complementary grain fractions or extracts/concentrates (for example, oat flour or bran, legume flours/fractions) to obtain food composites. These new composites provided excellent amino acid profiles and nutritional components and made them appropriate for uses in food manufacturing. The nutritionally significant components including fibers, antioxidants, essential amino acids, and food hydrocolloids found in the new composites prepared from SMHS make the composites useful as food ingredients for functional foods. Ultimately this project will provide the food industry with the opportunity to apply bioactive ingredients to their existing food product lines. We are exploring using hempseed protein’s gelling property for non-food applications.
New and value-added markets for SMHS by-products are important for improving the overall profitability of grain farmers. Food applications of these grains were the focus, but applications were also explored on the uses of processed and fractionated components for bioproducts that are comparable to commercial products. The antioxidants derived from the grains will also be tested as natural antioxidants in frying oil and other fat products. Innovative composites of SMHS grains and pulses, which are equally healthful and have complementary amino acid profiles, are considered for developing food items such as humanitarian rations and sport snack bars. We anticipate that these innovative SMHS-containing baked products will have better nutritional qualities and similar sensory profiles comparing to all-wheat baked goods.
Finding new uses for crops beyond SMHS that are currently regarded as animal feeds by developing health- promoting functional food ingredients and products along with byproduct utilization have been identified as the critical needs by various stakeholders. Silflower (Silphium), a member of sunflower family, is the crop identified by a group of stakeholders for potential uses as food and other value-added applications. Silflower is a perennial plant with long, drought-resistant roots that requires low agroeconomic inputs and makes it a great potential commodity crop for the western part of the United States which is experiencing a climate change induced drought. ARS has received a grant from The Land Institute for research in the value-added application of silflower seeds. The work is ongoing involving four ARS researchers.
Accomplishments
1. Developed near infrared spectroscopy (NIRS) technique for analyzing fatty acids in oils. Soybean oil accounts for 28% of the world’s vegetable oil consumption in 2019, with 24.9 billion pounds produced in the United States. Quality and stability of vegetable oils is determined by their fatty acid composition. The laboratory based chemical analysis is the most accurate way to measure the levels of seed components. However, these methods are time-consuming, expensive, very labor-intensive, and require special instruments. In order to develop a non- destructive and rapid test method for measuring fatty acid composition in seed oils, ARS researchers in Peoria, Illinois, developed an NIRS approach to accurately analyze the fatty acid composition. Over four years the ARS researchers collected 3000 soybeans samples grown in fields across 14 states in the United States and an additional set of soybean samples obtained from the USDA ARS Soybean Germplasm Collection located in Urbana, Illinois. The sample analysis of soybeans employed methods of both lab analysis and NIRS scanning. The laboratory based chemical analysis is the standard method for accurate but time consuming and expensive analysis; the scanning of NIRS machines is quick and required to be calibrated with chemical analytical data to be used as accurate and rapid alternative to wet chemistry lab analysis. This work demonstrates that NIRS can be a rapid method to determine fatty acid in large numbers of oil seeds. The knowledge and data generated in the study will be used in the effort to develop an inexpensive handheld NIRS device for use in oil seed analysis at elevators and processing plants.
2. Production of an odor-reducing, antibacterial clumping cat litter from soybean hulls. Cat litters usually are made from a special type of clay, known as bentonite, which absorbs urine and allows the litter to clump when it becomes wet. The bentonite is mined and litters from this clay present a long-term disposal problem. Some asthmatic cats are sensitive to the clay. Biobased cat litters can alleviate the problems (biodegradable and asthma friendly) but suffer an odor problem. Biochar, which is made from soybean hull using a kiln and later pressed into pellets, is an excellent absorbent for odor and liquids. ARS researchers in Peoria, Illinois, used the biochar, copper sulfate, which is antimicrobial and has also been previously found to reduce concentrations of the cat-urine compound, and an amylose inclusion complex to test the cat litter formulation. The resulting biobased and environmentally friendly formulation, treated with simulated cat urine, significantly reduced the growth of pathogenic bacteria and odor generated in the litter. A patent application based on this development has been filed and is being evaluated by a commercial cat litter company.
3. Researched hemp seed oil-based margarine for health-conscious consumers. Cold-pressed hempseed oil (HSO) has been known to have many health benefits due to many phytochemicals and high polyunsaturated fatty acids content. Margarines based on hempseed oil will be highly desirable for health-conscious Americans. In this study, ARS researchers in Peoria, Illinois, prepared oleogels, a solidifying material for making semi-solid fat products such as margarines, using HSO and natural waxes. Hempseed oil oleogels are intended to replace solid fats in commercial spreadable margarines. They evaluated oleogels’ firmness, crystal structures, and melting properties. The hardness of commercial grade margarine spreads was achieved with less than 3% wax added in the margarine while the hardness of stick margarines could not be achieved with up to 7% wax. This information is important for food companies that are seeking to develop healthier spreads incorporating oils with low levels of saturated fats and healthful bioactive components.
4. Soyhulls as a functional food ingredient. Soybean hulls, an abundant byproduct of soybean processing, contain rich phytochemicals, fibers, proteins, and minerals. Uses of soyhulls as functional food ingredients has never been attempted due to lack of information regarding the interactions among different ingredients in food matrices. ARS researchers in Peoria, Illinois, substituted amaranth or whole oat flour with up to 25% soybean hulls in gluten-free cookies. They examined various important properties of the four mixture of soybean hulls, amaranth and whole oat flour. The results demonstrated that soybean hulls, amaranth, and whole oat flour contain higher protein content, minerals, fiber, special amino acids, and critical vitamins (C and K) than wheat flour. Considerably higher total amino acid content was found in soybean hulls (18.33%) than wheat flour (12.77%). Water-holding capacities increased by replacing amaranth and whole oat flour with soybean hulls. Adequate water-holding capacity of food mixtures is important as it will not only affect shelf life of the food product but also impact the sensory profile and consumer experience of the food. Soybean hulls exhibited higher polymer-like elastic properties than amaranth, whole oat flour and wheat flours. The soybean hulls utilized in amaranth or whole oat flour cookies greatly improved their nutritional value and the water retention and moisture content, along with acceptable physical properties when compared to wheat flour cookies. This information will be useful in utilizing soybean hulls with amaranth and whole oat flour in gluten-free bakery products and other food applications.
Review Publications
Hwang, H., Winkler-Moser, J.K., Liu, S.X. 2022. Antioxidant activity of amino acid sodium and potassium salts in vegetable oils at frying temperatures. Journal of the American Oil Chemists' Society. 99(5):407-419. https://doi.org/10.1002/aocs.12585.
Lee, Y., Ma, F., Byars, J.A., Felker, F.C., Liu, S.X., Mosier, N.S., Lee, J., Kenar, J.A., Baik, B.V. 2021. Influences of hydrothermal and pressure treatments on compositional and hydration properties of wheat bran and dough mixing properties of whole wheat meal. Cereal Chemistry. 98(3):673-682. https://doi.org/10.1002/cche.10411.
Liu, S.X., Chen, D., Xu, J. 2022. Physiochemical properties of jet-cooked amaranth and improved rheological properties by processed oat bran. Future Foods. 5. Article e100107. https://doi.org/10.1016/j.fufo.2021.100107.
Hwang, H., Kim, S., Moser, J.K., Lee, S.L., Liu, S.X. 2022. Feasibility of hemp seed oil oleogels structured with natural wax as solid fat replacement in margarine. Journal of the American Oil Chemists' Society. 99(11):1055-1070. https://doi.org/10.1002/aocs.12619.
