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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Research Project #438610

Research Project: Nutritional Benefits of Health-Promoting Rice and Value-Added Foods

Location: Food Processing and Sensory Quality Research

2022 Annual Report

Objective 1: Develop commercially viable processing technologies that produce health-promoting foods from whole grain rice and rice co-products. [NP306, C1, PS1A, 1B] (S. Boue, J. Beaulieu) Sub-Objective 1.1. In this sub-objective research will characterize different rice processing techniques with emphasis on increasing health-promoting rice components (phytonutrients). Processing will include different cooking methods of table rice, parboiling, drum drying and extrusion of rice co-products. Sub-Objective 1.2. Establish temporal boundaries during sprouting between de novo synthesis of health-beneficial phytonutrient compounds versus catabolic loss or change in macronutrients. Objective 2: Enable commercial uses of whole grain rice and other crops as sprouts and microgreens in value-added foods and functional products. [NP306, C1, PS1B, 1C] (J. Beaulieu, S. Boue, Vacant - Sensory Scientist) Sub-Objective 2.1. Develop value-added products (e.g. beverages, powders, flours) from select, optimized, sprouted colored bran rice and grain varieties, and commercially important sprouted crops. Sub-Objective 2.2. Rice flour enriched with phytonutrients by sprouting and resistant starch by processing (from Sub-Objective 1.1) will be utilized as an ingredient in several rice functional foods.

Brown and colored rice will be analyzed using different cooking methods to determine methods to produce resistant starch and determine health benefits. Several processing methods will require rice to be milled to a flour. Rice processing methods and assays (in vitro and in vivo) to produce resistant starch and determine health benefits: Measurement of starch types will be conducted and compared to other starch sources. An in vitro fermentation system will be utilized to determine the effects of rice and rice ingredients on gut health. Research at the SRRC will germinate several rice varieties, including sprouted germinated brown rice, high protein rice and colored rice. Green technologies will deliver a free-flowing germinated brown rice beverage, with limited GRAS additions. A process developed at the SRRC has created the foundation for preliminary germinated brown rice beverages. Rice flour that is enhanced with resistant starch and polyphenolics from sprouted rice will be extruded into foods and analyzed for bioactive and phytonutrient content. Rice flour without added resistant starch and not sprouted will be the control. A sensory panel will determine if flavor and texture are comparable to foods produced from commercially available rice flour.

Progress Report
In support of Objective 1, we started small-scale sprouting of rice varieties with potential for value-addition. Sprouted varieties were Cahokia, Rondo, Scarlet, and Tiara. Previous work used Rondo brown rice for beverages and flour. Commercial producers have been growing Cahokia, a nonaromatic, high protein long grain brown since 2021. We used Scarlett (red) and Tiara (purple), two pigmented bran varieties for sprouting trials. In these experiments, we evaluated the macronutrients, phytonutrient, and volatile changes that occurred during the first 48-hours of germination. Additionally, our research group is buying a new extruder that will help in the production of resistant starch in rice flour. In support of Objective 2, ARS researchers at New Orleans, Louisiana, developed acidified cold-brewed sorghum bran beverages as a model system for planned rice bran beverage research and development. We analyzed bran and beverages for total phenolic content & profile, antioxidant capacity, condensed tannins, and proximate composition. We conducted a sensory study with 112 consumers to evaluate acceptability of sensory attributes and purchase intent of beverages (before and after an antioxidant message). We will use these results to develop and assess value-added acidified shelf-stable rice beverages made from antioxidant-rich rice bran. Rice mills have been obtained for in-house production of rice bran. ARS researchers at New Orleans, Louisiana, are developing lexicons (standard vocabulary used to describe products) for white, brown, red, and purple rice varieties to describe consumers’ sensory, emotional, and wellness perceptions. A modified individual sample description technique will be used to generate preliminary lexicons by visual evaluation of rice samples. Using photographic images of these samples, an online survey will be administered to refine the lexicons to the most relevant descriptors. We will also assess perceived quality and healthfulness based on visual cues. Sociographic and lifestyle predictors of health-promoting rice consumption will be determined. Rice processers and breeders will be able to use this information to guide product development, identify target consumers, and inform potential marketing strategies for novel rice varieties in the U.S. In support of Objective 2, We have evaluated several previously uncharacterized rice varieties for volatiles to determine possible aroma contribution in various rice fractions. Data showed significant differences in volatiles across varieties. Tiara purple rice had a robust aromatic profile that exceeded the other purple aromatic variety (known as IAC600.) The nonaromatic high-protein Cahokia brown rice had some of the highest levels of volatiles among the analyzed varieties. In contrast, the red Scarlett, had some of the lowest volatile values. As part of this work, ARS scientists identified several aroma compounds that are desirable to consumers in the examined rice. ARS scientists made progress in the agreement (No. 6054-41000-112-003S) with Tulane University. USDA scientists are utilizing rice sprouts from different varieties of brown and pigmented rice varieties to produce phytoalexins (antimicrobial compounds that some plants develop to protect against pathogens). Analyses have identified both flavonoid and terpenoid components in rice sprouts. ARS researchers are now evaluating both components for biological activity. Additionally, soybean seeds and sprouts have been stressed to produce phytoalexins, like glyceollins that have been shown to have health-promoting activities. ARS scientists are evaluating plant extracts and isolated components for health promoting effects. Collaborators at Tulane University scientists have employed a combination of 2D-cell and 3D-organoid systems to determine the mechanisms to which these extracts and isolated compounds lead to positive impacts on human health. Tulane have been providing updates in quarterly reports. We are evaluating soybean flour containing glyceollins for health benefits in several studies. In collaboration with a grant awardee on the 1890’s Faculty Research Sabbatical Program (6054-41000-112-002S), USDA scientists and collaborators are evaluating the effects of steeping and sprouting on the physicochemical and nutritional quality of hummus made from Bambara ground nut flour. The study indicates that the food and beverage industries can use steeping and sprouting treatments to develop Bambara groundnut flour with diverse properties, and improved application opportunities.

1. Lipid profiles improved in germinated brown rice beverages. Germinating brown rice is known to increase some health-promoting compounds. In collaborative research between the ARS in New Orleans, Louisiana, and Wyndmoor, Pennsylvania, researchers sprouted lipid-unstabilized brown rice using green technologies and enzymes for value-added beverages. ARS researchers at New Orleans, Louisiana, produced beverages from germinated rice and compared them against non-germinated brown and white brewers rice beverages. The germinated brown rice beverage contained significantly higher concentrations of total lipids and lipid-related compounds than the non-germinated brown and white rice beverages. Of the two types of rice studied, germinated brown rice beverages contained reasonable levels of lipids that are beneficial to human health. The findings are important as they can open up new markets for brown rice.

2. Comprehensive review clarifies discrepancies in compounds altered during rice germination. ARS researchers at New Orleans, Louisiana, have written and recently published a comprehensive review of 164 chemical parameters related to health and nutrition in germinated rice using a meta-data PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach. A PRISMA analysis facilitates a strict provenance in a systematic reviewer that transparently reports how and why the review was accomplished, what the authors accepted and rejected, and what the literature reveals in 164 parameters reported in 133 peer-reviewed world-wide rice sprouting manuscripts. An opensource database was made available containing levels of macronutrients, micronutrients, phytonutrients, and bioactive compounds in brown rice and germinated brown rice (Oryza sativa L.).

Review Publications
Beaulieu, J.C., Moreau, R.A., Powell, M.J., Obando-Ulloa, J.M. 2022. Lipid profiles in preliminary germinated brown rice beverages compared to non-germinated brown and white rice beverages. Foods. 11(2):220.
Beaulieu JC, Boue SM, Goufo P. 2022. Health-promoting germinated rice and value-added foods: a comprehensive and systematic review of germination effects on brown rice. Crit Rev Food Sci Nutr. doi: 10.1080/10408398.2022.2094887.
Beaulieu, J.C., Grimm, C.C., Obando-Ulloa, J.M. and McClung, A.M., Volatiles recovered in novel, diverse and uncharacterized rice varieties. Cereal Chemistry.
Chen, M., Bett Garber, K.L., Lea, J.M., McClung, A.M., Bergman, C.J. 2021. High resistant starch rice: variation in starch related SNPs, and functional, and sensory properties. Foods.
Eggleston, G., Triplett, A., Bett Garber, K., Boue, S., Bechtel, P. 2022. Macronutrient and mineral content in sweet sorghum syrups compared to other commercial syrup sweeteners. Journal of Agriculture and Food Research. 7. Article 100276.
Hatami, M., Soltani, F., Kalantari, S., Beaulieu, J.C. 2021. Evolution of polygalacturonase and pectin methyl esterase activity during the storage of dudaim melons harvested at two maturity stages. Italus Hortus. 28(2):58-69.
Wan, J., Wu, Y., Pham, Q., Li, R.W., Yu, L., Chen, M., Boue, S.M., Yokoyama, W., Li, B., Wang, T.T.Y. 2021. Effects of differences in resistant starch content of rice on intestinal microbial composition. Journal of Agricultural and Food Chemistry. 69(28):8017-8027.