Optimization of extraction of deoiled rice bran protein and its utilization in wheat based cookies

Abstract

Deoiled rice bran protein  was extracted using alkali extraction method Optimization of protein extraction by alkali extraction method was done using box-behnken design of response surface methodology (RSM). Yield and protein content of protein concentrate were found to be affected by extraction conditions viz. bran/water ratio, pH and time. pH had most significant effect on yield of protein concentrate followed by time of extraction and bran/water  of extraction solvent. Optimum process variables for extraction of protein concentrate from deoiled rice bran were 0.175 bran/water ratio, 9.5 pH of solution and 45 min of extraction time which gave 8.63% yield of protein concentrate having protein content of 83.75%. Albumin (37.23%), globulin (20.27%) and glutelin (46.82%) were found to be three major fractions of deoiled rice bran protein concentrate, while prolamin (1.18%) was a minor component. Highest antioxidative activity was detected in albumin fractions followed by glutelin, then globulin. Deoiled rice bran protein concentrate was incorporated on cookies at 1%, 2% and 3% level by replacing the wheat flour. Cookies with 1% level of incorporation of deoiled rice bran protein concentrate were most liked by the panel of semi trained judges.