高产γ-氨基丁酸益生菌发酵豆乳贮藏期间品质变化规律研究

Quality Change of High Yieldγ-Aminobutyric Acid Probiotics Fermented Soymilk During Storage

豆乳经益生菌发酵后不仅能改善风味,还能提升其功能特性。该试验依托前期筛选的高产GABA菌株:发酵乳杆菌SMN10-3(A)、乳酸片球菌SMN15-6(B)制备益生菌发酵豆乳,研究复配比例对发酵豆乳贮藏期间pH值、活菌数、GABA含量及滋味的影响。结果表明,A0B1组发酵豆乳活菌数最多,A2B1组GABA含量最高,达(1.736±0.004)mg/mL。贮藏期间A2B1发酵豆乳GABA含量降幅最小,pH值下降速率最慢,活菌数下降速度较平缓,在贮藏期内品质稳定性最好。该发酵豆乳在短期贮藏(7 d)时,滋味丰富度有所提升,但贮藏时间过长,风味也会出现一定损失。因此,发酵豆乳A2B1贮藏7 d时饮用为宜。

Soymilk fermented with probiotics can improve its flavor and enhance its functional characteristics.This experiment relied on the high yield(γ-aminobutyric acid,GABA)strains screened in the early stage:Lactobacillus fermentosus SMN10-3(A)and Pediococcus lactis SMN15-6(B)to prepare probiotic fermented soymilk.The effects of the combination ratio on the pH value,viable bacteria count,GABA content and taste of fermented soymilk during storage were studied.The results showed that the number of viable bacteria in fermented soymilk in group A0B1 was the highest,and the content of GABA in group A2B1 was the highest,up to(1.736±0.004)mg/mL.During the storage period,the GABA content of A2B1 group decreased the least,the pH decreased the slowest,the viable bacteria decreased at a gentle rate,representing that its quality stability was good during the storage period.The flavor richness of fermented soymilk was improved during short-term storage(7 days),but the flavor would also be lost if the storage time was too long.Therefore,it is advisable to drink fermented soybean milk A2B1 when stored for 7 days.