Chiou R Y, Cheng S L
Graduate Institute of Biotechnology, National Chiayi University, Chiayi, Taiwan, Republic of China.
J Agric Food Chem. 2001 Aug;49(8):3656-60. doi: 10.1021/jf001524l.
Soybeans were soaked with water for 4 h, steam-cooked, inoculated with the conidia of Aspergillus oryzae, and incubated for 3 days for koji preparation. The koji was then mixed with water-soaked and steam-cooked soybeans (1:2, w/w), ground into paste, and supplemented with 15% ethanol and 12.5% NaCl or 3% ethanol and 6% NaCl for miso fermentation at 30 degrees C. Daidzin, genistin, daidzein, and genistein contents were extracted from the lyophilized and pulverized soybean powder or from the miso homogenate by a developed one-tube procedure and analyzed with an HPLC. After water soaking, daidzein and genistein contents increased markedly, whereas daidzin and genistin contents decreased. Further increases of daidzein and genistein contents and decreases of daidzin and genistin contents were observed after koji mold growth. During fermentation, fungal and lactic acid bacterial (LAB) growth in the miso products was inhibited, whereas soluble protein contents increased much more rapidly in the low-salt miso products supplemented with 3% ethanol and 6% NaCl than the other products. When the 4- and 8-week-fermented miso products were cooked with tofu for sensory evaluation, flavor ratings of the low-salt products were higher than that of a popular commercial product. In both products, the most daidzins and genistins were hydrolyzed after 4 weeks of fermentation. The hydrolytic enzymes contributing to isoflavone transformation originated from soybeans after water soaking and from koji with mold growth. It was of merit that the low-salt fermented products were fairly acceptable in flavor rating and rich in daidzein and genistein contents after 4 weeks of fermentation.
大豆用水浸泡4小时，蒸煮后接种米曲霉分生孢子，培养3天以制备曲。然后将曲与水浸并蒸煮过的大豆（1:2，w/w）混合，磨成糊状物，并添加15%乙醇和12.5%氯化钠或3%乙醇和6%氯化钠，于30℃进行味噌发酵。通过改进的单管法从冻干并粉碎的大豆粉或味噌匀浆中提取黄豆苷、染料木苷、黄豆苷元和染料木素含量，并采用高效液相色谱法进行分析。水浸后，黄豆苷元和染料木素含量显著增加，而黄豆苷和染料木苷含量降低。曲霉菌生长后，黄豆苷元和染料木素含量进一步增加，黄豆苷和染料木苷含量进一步降低。在发酵过程中，味噌产品中的真菌和乳酸菌生长受到抑制，而在添加3%乙醇和6%氯化钠的低盐味噌产品中，可溶性蛋白质含量的增加比其他产品快得多。当将发酵4周和8周的味噌产品与豆腐一起烹饪以进行感官评价时，低盐产品的风味评分高于一种受欢迎的商业产品。在这两种产品中，大多数黄豆苷和染料木苷在发酵4周后被水解。导致异黄酮转化的水解酶在水浸后源自大豆，在曲霉菌生长后源自曲。值得注意的是，低盐发酵产品在发酵4周后风味评分相当可接受，且富含黄豆苷元和染料木素。
