Effect of microwave and enzymatic treatment on the recovery of protein from Indian defatted rice bran meal.

Defatted rice bran meal is an important source of protein along with other micronutrients. Rice bran meal has been utilized to produce protein isolates for potential application in various food products. Attempt has been made to increase the protein solubility by physical means like microwave digestion as well as by microwave digestion followed by homogenization. Simple 40 sec microwave treatment could give the protein recovery of 78.4% as against 28.9% after 1 min of conventional boiling and 40 sec is taken as optimum time for microwave treatment. The protein recovery is further increased by microwave treatment followed by homogenization. Defatted rice bran meal has also been treated with enzyme papain and viscozyme separately to increase the protein solubility. The yield of protein isolate (RPI), prepared by alkaline extraction followed by acidic precipitation is 10.2%, which is further increased to 14.5 & 22.4% by papain, viscozyme modification and 21.1 & 22.3% by microwave treatment and microwave treatment followed by homogenization respectively. A maximum of 82.5 and 82.6% protein has been recovered as soluble protein from de-oiled bran by viscozyme treatment and by 40 sec microwave treatment followed by 10 min of homogenization. So, microwave treatment along with homogenization is a suitable alternative processes in extracting protein from rice bran meal.