【摘要】 为增强对北京豆汁产品质量的控制,研究豆汁制备过程中微生物学、化学与生物化学的变化。结果表明:细菌产酸是导致绿豆乳自然酸化的主要原因,豆浆沉淀工序实属乳酸发酵过程;主要产酸微生物为乳酸乳球菌(Lactococcus lactis)和柠檬明串珠菌(Leuconostoc citreum)两个种系,且分别占72%与26%;泡豆工艺对绿豆淀粉含量影响不大,却使蛋白质含量显著降低,可溶性蛋白与氨基酸含量明显升高,说明浸泡促使豆子产生生理代谢:乳酸发酵导致可溶性蛋白及可溶性糖含量下降,游离氨基酸含量迅速累积,绿豆内源蛋白酶与淀粉酶活性下降,微生物蛋白酶活性增强。更多还原

【Abstract】 To enhance the product quality of Beijing traditional food "Douzhi", the microbiological, chemical and biochemical changes during its processing were studied. Lactic acid producing bacteria were confirmed accounting for the natural acidification of mung bean milk during sedimentation. The main fermenting bacteria came from two species: Lactococcus lactis and Leuconostoc citreum, which accounted for 72% and 26% of the total, respectively. Soaking brought little change in starch content, but caused a significant reduction in crude protein and sugars and an increased level in soluble proteins and free amino acids content. This suggests that a high metabolic activity is induced during steeping. Fermentation caused a rapid reduction in soluble proteins, soluble sugars and reducing sugars and a significant accumulation in free amino acids. Mung bean endogenous protease and amylase activity dropped significantly during fermentation, while the activity of microbial protease enhanced during the latter part.更多还原