玉米黄粉预处理工艺优化及其蛋白水解成分分析

以玉米黄粉为原料,利用α-淀粉酶和纤维素酶进行预处理去除淀粉、纤维素杂质,通过单因素法和正交试验对预处理工艺条件进行优化,以蛋白质回收率为考察指标确定最佳水解工艺。预处理后所得的玉米浓缩蛋白粉用8%的亚硫酸钠热变性处理,利用四种不同蛋白酶对玉米蛋白进行水解,以玉米蛋白水解度、溶解度、发泡高度和失水率为考察指标优选出水解玉米蛋白的蛋白酶种类,通过高效液相色谱分析玉米蛋白水解物的组成成分。结果表明,预处理的最适条件为:先用纤维素酶处理后用α-淀粉酶处理;纤维素酶最适温度50 ℃、pH5.0、酶用量1.0%、时间2.5 h、料水比1:3 g/mL;α-淀粉酶最适温度65 ℃、pH6.5、酶用量1.0%、水解时间0.5 h、料水比1:4 g/mL,此时蛋白质回收率为96.1%、蛋白质含量为89.9%。碱性蛋白酶为水解玉米蛋白最佳蛋白酶,此时玉米蛋白水解产物的水解度为14.2%,溶解度为68.6%,发泡高度为64 mm,失水率为16%。水解物中氨基酸含量为35.72%,多肽含量为64.28%。

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%.