Research Of Key Technologies Of Soy Sauce Fermentation With Multi-Strain

In this paper, Aspergillus oryzea Huninag 3.042 was used as the initial strain. A stain with high activity of protease and spores was obtained after rejuvenation.The methods of Plackett-Burman experiment, steepest ascent test and Box-Behnken response surface analysis were applied in optimum the condition of fermentation.The results showed that the optimal conditions of these variables were determined as:the culture temperature 22℃,initial pH 7.0,the initial water 1:0.8 proportion of soybean and bran wheat 4:6,particle size of soybean meal 6 mesh, ash content of 0.4%,phosphate solution 0.04 mol/L, After culturing under the optimized condition, the the neutral protease activity could reach 8.69 IU/ml increased by 38.3% than former.By researching on characterize property of Aspergillus niger 3.350, Bacillus natto, FlavoYeast and Monascus,it can be found that Aspergillus niger acid protease produced by Aspergillus niger can compensate for Aspergillus oryzea; Bacillus natto has a high salt tolerance, and enzymes provided by Bacillus natto can enhance protein utilization and formation of functional materials; Monascus red rice is not only enzyme-rich, but with high nutritional value, which containing the Monascus pigment can increase soy color rate; Flavor Yeast can format much more flavor material.A strain with high activity of amylase and glucoamylase named Rhizopus oryzea 3R-1 was isolated from rice alcohol.Koji was made by mixture strain of Rhizopus oryzea Aspergillus oryzae, Aspergillus niger. The result showed that the convention of starch and sugar content of soy sauce were high than that of Aspergillus oryzea.The results of koji produced by multi-strain showed that multi-strain is feasible in koji,and the best conditions of it was as following,the proportion of Aspergillus oryzea,Aspergillus niger and Rhizopus oryzae was 4:1:5,with 1% total inoculums.The method of orthogonal experimental design was applied in optimum of fermentation conditions.The optimal results demonstrated that 5% of red koji rice was added in butter and cultured to 14th day, then 5% inoculums of Bacillus natto was added and culture 2d, after that, salt added to make the sauce mash manipulation to salinity reached 15% and added 2% flavor Yeast.The result of fermentation with this technology performed that, the indications of soy sauce were better than the former, the utilization of nitrogen was increased by to 83.1%,the rate of production of amion acides was increased by to 53.8%.This study can provide a theoretic in brewing technology of soy sauce.