Title: An update on the use of co-products from the milling of rice in value added food products Author
Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 3, 2011
Publication Date: N/A
Interpretive Summary: Rice bran, rice wax, rice hull, and broken rice kennels are normally called by-products from the milling of rice; however, they contain ingredients that are healthy for human consumption. Instead of by-products, they are potentially equally valuable as the polish rice, and should be referred to as milled-rice co-products. This report summarizes the effort promoting the use and adding value to these co-products. Value-added rice products have been developed; including high-protein rice, low-fat frying batters, food coatings for various purposes, food additives with antioxidant capacities, and rice-based bakery products; such as, donuts and pancakes. These products are healthy substitutes using rice ingredients replacing the traditional wheat counterparts, which have the added advantage of being gluten-free to meet the needs of people with celiac disease problems.
Technical Abstract: Because of the huge quantity of rice produced annually, milled-rice co-products; such as, rice bran, rice oil, rice wax, rice flour, and rice hull are plentiful and readily available. These co-products could be valuable sources of food ingredients, but they have been vastly under-utilized. Rice bran and rice flour contain rice proteins. When treated with carbohydrate-hydrolyzing enzymes, they yielded high-protein products; which are nutritious, hypoallergenic, and widely used in health food and baby food formulations. Rice flour contains more than 90% rice starch (RS), and functional properties of RS are normally modified to suit the needs for food applications. Specifically, the addition of small amounts of phosphorylated RS esters, or pregelatinized rice flour to rice batters, was found to impart to the resulting fried product superior sensory characteristics, and a lowering of the oil-uptake by up to 50%, as compared with those of the traditional wheat counterparts. Similarly, other rice-based products; such as, edible films using rice wax and food additives with antioxidant activities were also developed. Treatment of RS with octenylsuccinic anhydride (OSA) produced OSA-RS esters with balanced hydrophilic-hydrophobic characteristics, useful as emulsifying agent for the encapsulation of lypophilic compounds.