将茅台酒曲中筛选出的高产游离大豆异黄酮(isoflavone aglycone,IA)乳酸菌——植物乳杆菌(Lactobacillus plantarum, strain CAU:228)引入大豆酸面团发酵体系。研究了酸面团发酵过程中4种大豆异黄酮单体、总酚含量及发酵前后大豆蛋白肽分子量分布的变化,对比分析了小麦面包、大豆面包、大豆酸面团面包的抗氧化活性及营养特性。结果表明:乳酸菌发酵可使大豆酸面团总IA含量提高9.87倍,总酚含量从3.83 mg GAE/g提高到5.29mg GAE/g,抗氧化活性肽的含量显著提高,酸面团面包中总IA含量达到了6.39 mg/100g,是大豆面包的2.93倍。大豆酸面团面包总游离氨基酸含量分别为大豆面包和小麦面包的2.02和2.84倍,DPPH与ABTS抗氧化能力相比显著提高。因此,大豆酸面团发酵技术在面包中具有较高的应用潜力。
A Lactobacillus plantarum (strain CAU: 228) with high free soybean isoflavone was screened from Maotai Qu starter to make soybean sourdough and breads. The changes of the content of 4 kinds of isoflavone monomers, total phenols during the fermentation of sourdough and the molecular weight distribution of soybean peptide before and after fermentation were analyzed. The antioxidant activity and nutritional characteristics of wheat bread, soybean bread and soybean sourdough bread were compared. The results showed that the total isoflavone aglycone content of LAB soybean sourdough was 9.87 times higher than that of unfermented sample. The total phenol content increased from 3.83 mg GAE/g to 5.29 mg GAE/g. The content of antioxidant peptides increased significantly. The total isoflavone aglycone content in soybean sourdough bread reached 6.39 mg/100g, which was 2.93 times of that of soybean bread. The total free amino acid content of soybean sourdough bread was 2.02 and 2.84 times higher than that of soybean bread and wheat bread. The antioxidant capacity of soybean dough bread DPPH and ABTS was also significantly higher. Therefore, this LAB strain has a high potential for application in soybean sourdough bread.