Bioactive compounds from by-products of rice cultivation and rice processing: Extraction and application in the food and pharmaceutical industries

Background: Rice by-products, including straw, husk and bran, are generated through rice cultivation and rice milling processes and have been considered as rich sources of bioactive compounds, such as essential amino acids, phenolics, flavonoids, vitamin E and gamma-oryzanol. These compounds are generating interest due to their potential beneficial effects on human health, in addition to their antioxidant capability for improving the storage stability of foods. Nevertheless, a large amount of rice by-products is not efficiently utilized, which leads to economic waste and environmental problems. Scope and approach: This review presents an overview of recent studies on the extraction and application of bioactive compounds from rice by-products. Several extraction techniques, including extraction solvents, have been developed and optimized in recent studies to provide greater chemical properties and antioxidant activity to the extracts. Further, the utilization of extracted bioactive compounds from rice by-products in the food and pharmaceutical industries is also highlighted in this review. Key findings and conclusions: The utilization of waste and by-products from rice cultivation and commercial rice processing has generated increased interest as a means to improve human health, increase farmer income, and reduce environmental pollution. Bioactive compounds from these byproducts can be used in many ways, such as for food colorants, food enrichment, food preservatives, anti-cancer agents, or anti-inflammatory agents. In addition, they can also be applied as alternative compounds, instead of synthetic food additives or drugs.