Studies on Antioxidant Activity of Polished Glutinous Rice Hydrolysates

Dilute homogenate was prepared with grinding glutinous rice.The hydroxyl free radical scavenging activity(SA) of the glutinous rice dilute homogenate hydrolysate,which was produced by hydrolysis with four kinds of different protease,was investigated by examining the absorbance with 721 UV-Spectrometer.The result revealed that the radical scavenging activity of the hydrolysate increased significantly after the glutinous rice homogenate was hydrolyzed with different enzyme.The hydrolysates digested with neutral protease showed the highest scavenging activity among the four kinds of protease.The most suitable hydrolysis parameters of neutral protease,determined by the orthogonal test design based on the single factor experiment,include substrate protein concentration 2 %,enzyme /substances ratio 24 000 U/g,temperature 55 ℃,pH=8 and time duration 0.5 h,with the scavenging activity 56.05 % of hydroxyl free radical.The variance analysis of affecting factors of scavenging activity on hydroxyl free radical indicates that temperature,pH,enzyme,substrate concentration all have great effect on antioxidant activity and have significant difference.