Productions of rice bran protein concentrate and study some of its functional properties

Large quantities of rice bran are generated as by-products during the milling of rice in Iran. Although the rice bran protein has high quality and usability in food industry but rice bran is used less now. For better use of rice bran protein, it is desirable to develop effective methods to separate or concentrate the protein component from this by product. In this investigation, with using of 1 N NaOH and in alkaline condition the rice bran protein concentrate was prepared by extraction of rice bran protein. Proximate composition, amino acid profile, and functional properties including water solubility, foam capacity and foam stability, emulsifying properties, water and oil absorption of rice bran protein concentrate were determined. The protein concentrate yield was 75%. The results of amino acid composition analysis showed that the lysine content, at 2.25%, and methionine content, at 2.17, of rice bran protein concentrate were lower than other amino acids. Water and oil absorption of rice bran protein concentrate were 2.01(g water/g protein) and 2.09 (g oil/g protein), respectively. Rice bran protein concentrate showed good emulsifying properties. Foam capacity was good in rice bran protein concentrate (P<0.05) but foam stability had decreased after 60 min until 60%. In conclusion, the amino acid composition and functional properties of rice bran protein concentrate was showed that this value-added product could be used as protein ingredient in livestock and aquaculture feed industry.