| The soy sauce is a kind of traditional condiment with Chinese characteristics, and has a long history. Currently there are three main processing technologies, which are the high-salt diluted state fermentation, low salt solid state fermentation, and part-brewing solid-diluted state fermentation which combine the former two. Among them, the high-salt diluted state fermentation is better because of the soy sauce made by it has the best quality and flavor. But it also has some shortcomings, such as the long lasting period, high investment, more space needed, low utilizable ratio of protein, low production of the amino acid and so on.The main purpose of this experiment is to study the processing technology of the high-salt diluted state fermentation systematicly. From soy sauce strains screening, koji-making, bacterium expanding and the parametric ascertaining in the latter fermentation, to raise the protein utilizable ratio and amino acid productive rate. The contents including: (1) the soy sauce strains screening and rejuvenescence; (2) best culture condition of strains expanding and ascertaining; (3) best matching ratio of double strains culture ascertaining; (4) best condition of koji-making and ascertaining; (5) the parametric ascertaining of the latter fermentation.The mainly conclusions are as follows:1. Using the lucent circle marks to screen and rejuvenescenced the Aspergillus oryzae and Aspergillus Niger V.Tiegh respectively, combined with the bacterial diameter as a main indicator, combining the spore number and the enzyme vigor. The M-1 Aspergillus oryzae and H-1 Aspergillus Niger V.Tiegh were choosed as the strains in follow-up experiment.2. M-1 Aspergillus oryzae is cultured expandingly in triangle bottles. The best matching ratio of cultivating materials is: bean dregs : bran: flour=6: 2: 0.8. The other parameters include, the water content is 68%, and cultivating temperature is 32-34℃. After 60-72h, its various physical and chemical indexes and the organoleptic evaluation are best. And the expanding culture verifies further that the function of the strains is fine when they are cultivated in this condition.3. The H-1 Aspergillus Niger V.Tiegh were screened. The medium ratio is bean dregs: bran: flour=6: 2: 0.8, water content 68%, 34-36℃for72-84h, it shows the best physical and chemical indexes and the organoleptic evaluation. And also, the expanding culture verifies further that the function of the strains is fine when they are cultivated in this condition.4. During the process of koji-making, steeping and steaming beans is the first critical unit operation. The best time of steeping beans is about 7 hours,under constant temperature of 30℃and the most suitable trunk/wet ratio is 1:2.0-2.1. Besides, steaming in the revolvable high-pressure cooker is the optimum way, with the pressure 0.13 MPa, for 3 Min.5. The combination of Aspergillus oryzae and Aspergillus Niger V.Tiegh is the second critical unit operation. And the best matching ratio of them is 4:1.6. The third critical unit operation is the koji-making, which contains the optimum culturing temperature and time. The results shows that 30-36℃,40-44h is ideal.7. In the later fermentation, the concentration and quantity of the brine, the time of fermentation and the effect of the enzymes were mainly studided. From the experiment, it can be known when the salt of soy sauce mash is 15%-16% and the quantity of brine is 2.2 times of the cultivating material is best. Also, the ideal time of fermentation should be more than 120 days. And at the same time, complex enzyme can improve the clarity of soy, and raise the rate of production, and also the better quantity is 1.0%.
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