液态发酵大豆肽分子量分布与酶分布关系研究

Study on relationship between enzyme and molecular weight distribution of soybean peptides by liquid-state fermentation

大豆肽在食品和保健品领域应用广泛,是一种颇有前途功能性食品,大豆粕含45.0%～55.0%大豆蛋白,经水解可得由3～6个氨基酸组成功能性大豆肽。发酵过程中,低分子量肽百分含量、肽转化率和酶分布与发酵条件有关,利用枯草芽孢杆菌1389、黑曲霉3.350和米曲霉A–9005发酵大豆粕,通过这些微生物所分泌各种蛋白酶对大豆粕蛋白质合适位点切割,及对某些肽基团和疏水性氨基酸末端进行修饰和重排,可达到降低成本、提高利用率和产率目的。该实验研究枯草芽孢杆菌1389分别和黑曲霉3.350、米曲霉A–9005混合发酵大豆粕制备大豆肽动态发酵过程中低分子量肽百分含量、肽转化率和酶分布之间相关性;结果表明,发酵温度30℃,接种量为10%,底物浓度3%,枯草芽孢杆菌1389与黑曲霉3.350菌种混合比3∶2,发酵36h时,低分子量肽百分含量65%以上,肽转化率70%左右,为最佳发酵条件。

Soybean peptides that is widely used in the fields of the food and health products is a promising functional food. Defatted soybean meal contain 45.0%-55.0% soybean protein, when it is hydrolyzed, we can get functional soybean peptide that is composed of 3～6 amino acids. In the fermentation process, the molecular weight distribution of soybean peptides, conversion rate of peptides and the distribution of the enzyme systems are related to fermentation conditions. Making use of Bacillus subtilis 1389, Aspergillus niger 3.350 and Aspergillus oryzae A-9005 ferments defatted soybean meal, in fementation process, various kinds of protease secreted by these micro-organisms cut defatted soybean meal in suitable cutting sites and then modify certain groups of peptides and hydrophobic terminal amino to the purposes of reducing the costs and improving the rate of utilization and production.This paper analysis the correlation of different indicators through regulation of the changes of indicators and determination the most optimal fermentation conditions of Bacillus subtilis 1389 mixed with Aspergillus niger 3.350 and Aspergillus oryzae A-9005.The study results that the fermentation temperature is 30℃, inoculum concentration is 10%, substrate concentration is 3% on the conditions of mixing with Bacillus subtilis 1389 and Aspergillus niger 3.350, mixing ratio is 3 ： 2, the fermentation time is 36 hours, molecular weight distribution of soybean peptides is 65%, and peptide conversion rate around 70%, is the best fermentation conditions.