小麦蛋白酶水解制备面包风味前体物质的研究

Enzymatic Hydrolysis of Wheat Protein for the Production of Precursors of Bread Flavor

以水解度和感官评定为指标,研究风味蛋白酶、中性蛋白酶和复合蛋白酶对小麦蛋白的水解作用和美拉德产物风味的影响。结果表明,风味蛋白酶最合适用于制备面包风味前体物质。通过正交实验确定最佳水解条件,采用底物质量分数5%,p H 7.0,风味蛋白酶加酶量2 000 U/g,在50℃酶解2.5 h,所得酶解产物为最佳面包风味前体物质,得到的水解度为35.50%。分析不同时间酶解液中氨基酸和相对分子质量对美拉德产物影响,发现水解2.5 h面包风味前体物质中对面包风味形成起贡献的氨基酸质量浓度分别比0.5 h和1.5 h的酶解液多5.24 mg/m L和3.91 mg/m L,总游离氨基酸的质量浓度分别多7.42 mg/m L和4.45 mg/m L,具有更高美拉德反应程度的肽相对分子质量小于3 861的占比分别增加6.79%和1.59%,尤其是相对分子质量小于1 405占比分别增加12.34%和3.34%。SPME/GC-MS分析结果表明:面包风味前体物质制备得到的美拉德产物具有面包焙烤特征风味。

Wheat protein was hydrolyzed by proteases Flavourzyme, Neutrase and Protamex withFlavourzyme being the best for the production of precursors of bread flavor and the maximum degreeof hydrolysis(DH). Based on orthogonal experiments the optimum hydrolysis parameters were:substrate concentration, 5%; Flavourzyme concentration, 2 000 U/g; p H, 7.0;temperature, 50 ℃;time, 2.5 h. Under the condition, a DH of 35.50% was reached and Maillard reaction products as theoptimum precursors of bread flavor were obtained. The hydrolysate contained 5.24 and 3.91 mg/m Lmore amino acids for bread flavor, 7.42 and 4.45 mg/m L more total free amino acids, 6.79 and 1.59%higher contents of the portion with the molecular weight(MW) below 3 861, and 12.34 and 3.34%higher contents of the portion with the MW below 1405 Da than those of 0.5 h and 1.5 h, respectively.The portion with the MW below 3861 Da was favorable to the Maillard reaction. SPME/GC- MSanalysis proved that the Maillard reaction products formed the key bread flavor. This paper encouragesthe further study for the production of bread flavor compounds via the Maillard reaction.