The contrast tests of enzyme-producing capability of rhizopus strains including C-24,Q303,3866,702 and YG5-5 which were widely used in China were carried out to study the effects of culture medium,water addition level,culture temperature and raw materials on enzyme-producing capability,to investigate the physiochemical property changes of rhizopus,and to sum up the optimum starter-making conditions.
Two esterifying bacteria strains including SGAS2004.0001 and SGAS2004.0002 were obtained by transparent circle method coupled with the test of esterifying capability,alcohol resistant capability,and acid resistant capability. In addition,SGAS2004.0001 was used in liquor-making and starter-making experiments.
And addition of 0.5 %～1 % esterified red yeast in starter-making materials to produce strengthened daqu could improve esterification power by 3.8 mg/g (16.8 % increase), addition of 8 % esterified red yeast in esterified liquid production could increase ethyl caproate content above 25 g/L. (Tran. by YUE Yang)
The rate of lobster head, lobster crust to bean dregs to flour to wheat bran is 40~50∶35~40∶5~10∶10~15. With this rate, after the process of koji-making, fermentation, soaking and drying, lobster soy source is made.
Good color was obtained by several measures,including short-time steaming for raw materials(30-40 min),koji-making at low temperature(30℃)) for a short term of 46-48 h,fermentation for 2-3 months and removing spore from mature koji.
The comparative study on enzyme productivity was carried out among Rhizopus strains C-24,Q303,3866,702 and YG 5-5.The influences of culture medium,moisture addition,culture temperature and materials on enzyme production were investigated. The variation of physicochemical properties of different strains during koji making was also analyzed.
Effective results were achieved: the amount of koji spore, the enzyme activity of making koji, the reducing sugar in finished sweet paste made by binary koji, and the amino nitrogen were increased by 20%, 4.64%, 4.3%, and 8.45%, respectively. The sterilization process reduced the loss of amino nitrogen and reducing sugar by 4% and 3.5%, respectively.
The ratio of soy meal to cotton meal to wheat bran and flour was 40:20:36:4. By applying the technique of making koji with mixed strains and fermenting with solid moromi and low commen salt,the acid protease vitality of koji increased by 26% over that of monostrain and the ratio of the total nitrogen amounted to 78. 89%.
The result shows that taking the liquefaction technique under the condition that the starch raw material is out of the process of making koji can save 40% of starch raw material and the overplus can be used to produce the modified starch. The advantage of this method is to increase the solid content without salt and to enhance the cohesiveness of soy sauce.
According to the production experience, quality of Aspergillus oryzae HuNiang 3.042, equipment and condition of koji making, process of koji making, koji preservation and management were introduced, in order to ensure the quality of soy sauce koji.
For improved fermentation of shoyu (soy sauce), a useful koji-making system has been developed using a mixed tane-koji of two shoyu koji moulds, namely Aspergillus oryzae K2 (length of conidiophores about 350 μm) and the late-conidiation strain, A.