Location: Functional Foods Research
2024 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 or extracts such as proteins, 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 or extracts such as proteins, 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 or extracts such as proteins, 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
Research conducted during the current reporting period has generated knowledge and technologies for developing new functional food opportunities, functional food ingredients, market applications, and products with increased health benefits.
Under Objective 1: Sorghum, millet, and hemp seed (SMHS) flours were created from commercial whole seeds milled, further processed into different fractions and, in many instances, treated with thermomechanical processes. Thermomechanical processes such as steam jet cooking, steam explosion, 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 also examined after treatments. Data analysis indicates the property change from processing of SMHS grains enables SMHS fractions/components to be used in existing formulations of a wide range of baked goods including cookies, noodles, cakes, and gluten-free breads.
Hemp research presents a unique issue. Hemp (Cannabis sativa L.) is an annual herbaceous plant that belongs to the Cannabinaceae family. The cannabinoids are accumulated in the glandular trichomes found on the flowers.
Due to regulations in the United States, it is critical to ensure that the maximum concentrations of Cannabidiol contents not exceeding the 0.3% total Tetra hydro-cannabinolic acid (THC) limit as defined by the federal regulations. Current methods developed for measuring cannabinoids are time-consuming requiring expensive equipment, solvents, and expertise. Near-infrared spectroscopy (NIR) has shown promise for quick and easy means to different components in agricultural products. ARS researchers in Peoria, Illinois, have developed methods to measure THC concentration quickly and accurately.
Research on silflower (Silphium integrifolium Michx), a perennial herb native to the central prairie region of the United States with significant amounts of proteins, oil, and carbohydrates, started in Fiscal Year (FY) 2023 and continued in FY 2024. ARS researchers in Peoria, Illinois, are developing methods of extracting proteins from defatted silflower seed meal, eliminating antinutritional components, and reducing unpleasant tastes. These studies have created healthful alternative ingredients for gluten intolerant consumers but also for providing food products that deliver improved health benefits for consumer markets. Research was also conducted by adding healthy legumes or their byproducts such as soyhulls to these processed fractions or flours that can be used to develop nutritionally balanced food products and meet the requirements of commercial scale production.
Under Objective 2: ARS researchers in Peoria, Illinois, conducted research on applications of newly developed fractions and flours of various specialty grains in various food categories. For some studies, the fractions or flours after processing (using milling and/or steam jet cooking, and in some cases sprouting and enzymes) were used as healthy replacements for formulations of commercial food products (baked products or noodle as well as beverages); in other studies, researchers blended them with other food materials or nutritionally or/and functionally complementary grain fractions or extracts/concentrates (e.g., soyhulls, oat bran, legume fractions) to obtain food composite materials that retained consumers’ acceptability and enhanced nutritional and healthful qualities.
Researchers studied proso millet (Panicum miliaceum) that is drought, pest, and disease resistant compared to other major cereals. Researchers evaluated the effect of whole grain roasting temperature and time on the phenolic compounds, starch digestibility and functional properties of whole and ground millets. This study will provide the food industry with the opportunity to add this nutritionally interesting and healthy sources of food ingredients to their existing food product lines.
ARS researchers in Peoria, Illinois, patented a biobased cat litter with milling byproducts of soybeans for the development of renewable biobased cat litter and are engaging with potential partners for commercial production and marketing. Researchers explored innovative ways of removing dark color and bitter taste of extracted proteins from Silflower seeds. It will provide additional value- added income stream for silfower value-chain stakeholders and impact the sunflower seed industry as sunflower is closely related to silfower and has the same issue with color and flavor for their defatted meals or extracted proteins. ARS scientists in Peoria, Illinois, discovered silflower seed oil contains an unusually large amount of squalene, an important ingredient used in vaccine and skincare products. Currently, commercial source of squalene is extracted from deep sea shark liver oil.
Accomplishments
1. Identified that roasting of whole millet leads to better digestibility and bio-availability of healthful nutrients in flour. Proso millet (Panicum miliaceum) is a drought tolerant cereal crop. The protein content of millet grain is like that of wheat, but it is gluten-free, and is high in calcium and iron. But millets are underutilized for human consumption due to lack of awareness of nutritional benefits, presence of anti- nutritional components and inconveniences in food preparation. Therefore, there is a need for processing technologies to improve the properties of millets for food applications. Roasting is a dry heat treatment, commonly used to enhance flavor and reduce antinutrients such as phytic acid and saponins. ARS researchers in Peoria, Illinois, roasted whole millet grains at 150°C for 0, 15, 30, 45 and 60 minutes and measured the functional properties to evaluate the roasted flour. Roasting significantly affected the digestibility, pasting properties, color and phenolic contents of millet flours. Roasting millets provide better functionality and properties needed for the development of various functional healthy food products, which are especially suitable for consumption by the gluten-sensitive population.
2. Identified that particle size separation results in fiber and protein shift but the yield and efficiency of protein extraction is reduced. Pre-processing of silflower seed show promise in improving the color and yield of extracted protein and reducing the phenol content. Silflower (Silphium integrifolium Michx.) is a perennial plant that has long, strong, deep, extensive root systems, which can prevent erosion, capture dissolved nitrogen, and out-compete weeds eliminating the need for frequent irrigation and herbicide uses. Silflower seeds are of interest as a potential plant protein source. For use as a food ingredient, the color must be light, preferably white, and bland tasting. Protein extracted from whole defatted silflower seeds is dark in color due to the extraction of phenolic compounds such as chlorophyll, chlorogenic acids. Dehulling poses another challenge as the kernel is fused in wings that are covered with a thick seed coat. Processing methods such as, fine-milling and particle size separation can cause a protein shift resulting in protein-rich and fiber-rich fractions. But yield and purity of the fraction is low. ARS researchers in Peoria, Illinois, used different processing methods to lighten the color and increase the yield of extracted protein. It was found that fine milling raw silflower seeds resulted in a protein shift to fine particle size fraction, while the coarse fraction had higher amounts of seed coat. The protein extracted after defatting the fine fraction resulted in lighter color. The color was further improved when the raw silflower seeds were treated by soaking in mild solvents, rinsing with water and drying prior to milling without affecting the yield of extracted protein.
Review Publications
Hwang, H., Liu, S.X., Moser, J.K., Singh, M., Van Tassel, D.L. 2024. Composition and oxidative stability of silflower (Silphium integrifolium) seed oil and its potential as a new source of squalene. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.12814.
Mutuyemungu, E., Motta-Romero, H., Yang, Q., Liu, S., Liu, S.X., Singh, M., Rose, D. 2023. Megasphaera elsdenii, a commensal member of the gut microbiota, is associated with elevated gas production during in vitro fermentation. Gut Microbiome. https://doi.org/10.1017/gmb.2023.18.