Effect of Compound Protease Treatment on the Quality Characteristics of Wheat Germ Powder

Wheat germ powder was hydrolyzed by compound protease, and the effects of ratio of material to liquid, amount of enzyme and hydrolysis time on the quality characteristics of wheat germ powder were analyzed. At the same time, three groups of enzyme hydrolyzed powder with the highest water solubility index of wheat germ hydrolyzed powder and milk powder were compounded and sensory evaluation was made to determine the best compound ratio. The results showed that the quality of wheat germ powder hydrolyzed by protease was better than that of wheat germ ultrafine powder. When the ratio of material to liquid was 1:5 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the water solubility index of wheat germ powder reached the maximum, which was 60.6 g/g. Compared with the water solubility index 30.22 and 30.65 g/g of raw powder and ultra-fine powder, the water solubility index of wheat germ powder increased by about two times after enzymatic hydrolysis. When the ratio of material to liquid was 1:4 g/mL, the amount of enzyme was 4400 U/g and the reaction time was 2.5 h, the absorbance value decreased from 0.501 to 0.348 of unhydrolyzed wheat germ powder, and the lipase activity in enzymatic hydrolyzed wheat germ powder reached the minimum. After enzymatic hydrolysis with compound protease, the water solubility index of wheat germ powder was greatly increased, the lipase activity of wheat germ powder decreased, and the effect of enzymatic hydrolysis on the color difference of wheat germ powder was not significant. In the experiment of compounding with milk powder, whether it was wheat germ powder, ultra-fine powder or enzyme hydrolyzed powder, the highest sensory scores was obtained when the addition amount was 30%.