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Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Review Article Publication Acceptance Date: 10/21/2013 Publication Date: 11/1/2013 Citation: Friedman, M. 2013. Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells – a review. Journal of Agricultural and Food Chemistry. 61:10626-10641. Interpretive Summary: Rice (Oryza sativa L.) is a major source of nourishment for the world’s population. World production of rice is estimated at around 680 million tons, equivalent to that of wheat. A byproduct of rice processing is rice bran and the agricultural ‘waste’ product, rice hulls, which protect rice seeds during growth, accounting for 20% of the rice crop. Rice bran serves as a source of widely studied rice bran oil and numerous individual bioactive compounds, many of which have been shown to exhibit beneficial effects in cells, animals, and humans. This accounts for the extensive literature on the multifaceted aspects of rice bran, oils, and hulls. There is a need for a comprehensive review that encompasses food and industrial uses and the relationship of composition to bioactivities.This overview therefore surveys and interprets our present knowledge of the chemistry, food and industrial uses, and antioxidative, anti-inflammatory, antiallergic, anticarcinogenic, anticholesterol, antidiabetic, and antimicrobial activities of rice brans, rice bran oils, and rice hulls in cells, animals, and humans. Further research is suggested for some of these categories. The described findings are not only of fundamental interest that might help our understanding of the production and biological functions of rice-derived brans, oils, and hulls, but also have practical implications for food chemistry, allelochemistry, agriculture, industry, and medicine that could lead to better foods and improved human health. Technical Abstract: Rice plants produce bioactive rice brans and hulls that haven been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition, and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, we also present brief summaries on the preparation of health-promoting food including bread, noodles, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional food as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described multifaceted and multifunctional aspects of the rice-derived products in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies. |
