Chapter 3 - Rice: A Source of Plant Protein with Many Valuable Processing Co-products


Janitha P.D. Wanasundara, Hitomi Kumagai, Alicia P. Kasch, Laurie Van Gels, Steve Peirce,
Chapter 3 - Rice: A Source of Plant Protein with Many Valuable Processing Co-products,
Editor(s): Sudarshan Nadathur, Janitha P.D. Wanasundara, Laurie Scanlin,
Sustainable Protein Sources (Second Edition),
Academic Press, 2024, Pages 55-75,

Résumé en langage clair

As the third chapter of the book "Sustainable Protein Sources: Advances for a Healthier Tomorrow" presents on rice as a source of proteins. Rice is a critical protein source that ensures food security of half of the world population. Nutritional value of protein in rice grain and bran, effect of processing and potential uses of co-products of rice processing is presented in detail.


Rice is the staple for more than 3.5 billion people of the world and plays a critical role in food security for more than half of the world’s population. A majority of present-day rice consumed around the world is from Oryza sativa and the subspecies japonica and indica, and javonica to a lesser extent. Total protein content of the edible components of rice grain is ~16%. Most of the protein bodies (PB) are located in outer coatings (bran) of the starchy endosperm and the germ, which are removed during milling and polishing to obtain white rice grain.

Rice protein is rich in glutamine and asparagine like other cereal proteins. Glutelin (oryzenin) and prolamin (aqueous ethanol soluble) proteins constitute 80% and 20%–25% of rice endosperm protein, respectively. The lysine content of glutelin is higher than other proteins found in rice. PB that contain most of the proteins are mostly concentrated in the aleurone and subaleurone layers and some are found with starch granules of the endosperm. Albumin and globulin exist in the outer layers of the brown rice grain, accounting for 4%–22% and 5%–13% of total protein, respectively.

Protein products developed from rice bran, broken rice, and germinated brown rice are available in the market. Hypoallergenic and nutritional properties are the highlights of rice protein products, making them competitive with leading alternative protein products. Potential new uses of rice protein including rice bran will be based on the accumulating science evidence on the bioactivities of the constituting components. Processing co-products of converting paddy to edible rice generate valuable ingredients to the food industry supporting sustainability and circularity of rice crop.

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