酶法制备燕麦多肽的工艺条件优化及分析

Optimization and Analysis of Process Conditions for Enzymatic Preparation of Oat Peptides

燕麦蛋白是一种优质谷物蛋白,但其营养价值开发利用率较低,为提高燕麦蛋白生物价值的利用,以水解度为考察指标,采用响应面优化法对碱性蛋白酶酶解燕麦蛋白的工艺条件进行优化。另外,将制得的多肽经过超滤得到小于5 kDa的片段,并通过测定其不同浓度的1, 1-二苯基-2-三硝基苯肼(1, 1-diphenyl-2-picrylhydrazyl radical,DPPH)清除率和羟自由基清除率验证其体外抗氧化活性。得到最佳酶解条件:碱性蛋白酶Alcalase 2.4 L FG使用量1.6 mL/L,底物浓度10%,酶解时间150 min,温度52℃, pH 9.2。在此条件下,燕麦蛋白的水解度为14.86%,多肽得率为19.02%。燕麦多肽清除DPPH的IC值为9.112 mg/mL,清除羟自由基的IC值为3.062 mg/mL。结果表明,经过响应面法优化制得的燕麦多肽具有较高的体外抗氧化活性。

Oat protein is a high-quality cereal protein with a reasonable ratio of amino acids,which is close to the nutritional model recommended by FAO/WHO.Furthermore,previous studies have shown that peptides have higher utility value than proteins.In order to improve the using of biological value of oat protein and obtain peptides with higher biological activity,the hydrolysis condition of oat protein with technological alkaline protease was optimized by response surface optimization methods,which was evaluated by the degree of hydrolysis.In addition,the prepared peptide was purified via ultrafiltration to obtain the fragments with molecular weights less than 5 kDa.Its anti-oxidant activity in vitro was investigated by measuring the scavenging activities of DPPH free radical and hydroxyl at diferent concentrations.The best condition of oat peptide enzymolysis was alcalase 2.4 L FG dosage of 1.6 mL/L,substrate concentration of 10%,enzymolysis time of 150 min,temperature of 52 ℃,and pH of 9.2.In this case,the degree of hydrolysis reached 14.86%,and the peptide yield was up to 19.02%.The IC50 value of oat peptides for scavenging DPPH and hydroxyl radicals were 9.112 mg/mL and 3.062 mg/m L,respectively.The results showed that the oat peptides optimized by response surface methodology could exhibit high antioxidant activity in vitro.