Optimization of Pretreatment Process of Corn Gluten Meal and Analysis of Its Proteolytic Components

Corn gluten meal was used as raw material to pretreat corn gluten by α-amylase and cellulase to remove starch and cellulose impurities. The pretreatment conditions were optimized by single factor method and orthogonal test. The optimal hydrolysis process were determined by protein recovery rate. The corn protein concentrate powder obtained after pretreatment was heat-denatured with 8% sodium sulfite, and the corn protein was hydrolyzed by four different proteases. The proteases of hydrolyzed zein were selected based on the degree of corn protein hydrolysis, dry product recovery rate, foaming height and water loss rate. The components of zein hydrolysate were analyzed by high performance liquid chromatography. The results showed that the optimum conditions for pretreatment were treated with cellulase and then α-amylase. And cellulase optimum temperature was 50℃, pH was 5.0, enzyme dosage was 1.0%, hydrolysis time was 2.5 h, material to water ratio was 1:3 g/mL. α-amylase optimum temperature was 65℃, pH was 6.5, enzyme dosage was 1.0%. Phydrolysis time was 0.5 h, material to water ratio was 1:4 g/mL. Protein recovery rate was 96.1%, protein content was 89.9%. Alkaline protease was the best protease for hydrolyzing zein, and the dry product recovery rate of zein hydrolysate was 14.2%, the solubility was 68.6%, the foaming height was 64 mm, and the water loss rate was 16%. The amino acid content in the hydrolysate was 35.72%, and the polypeptide content was 64.28%.