Research On The Development Of Mold Low-salt Sufu Powder And Its Influence Factor

Sofu powder is Chinese traditional fermented soybean food, with abundant nutrition. In traditional manufacture of this product, the processing period is long and the salt content of the product is high, which constrain the development. This study attempted to screen strains of traditional Chinese fermented sufu powder and improve process. Its production process was without molding and pickled stage which shortened the production cycle of sufu powder.Through single factor experiments on growth temperature. pH. salt and amino acid nitrogen content filtering, we identified Actinomucor elegans as the mold fermentation strains. Through orthogonal experiment, the optimized fermentation conditions were obtained as flollows:the amount of Actinomucor elegan inoculated spores was1.0×107cfu/mL. the amino acid nitrogen content had reached0.64%at the temperature of28℃for three days. Using Minitabl4.0analysis software to design response surface experiment of protease ripening process optimization, the optimized conditions were obtained as flollows: the substrate concentration was13.0%(W/V), the protease concentration was10.0μL/L. hydrolysis temperature was50.3℃. hydrolysis duration was5.2h. adding3.0%(W/V) NaCl and4.0%(W/V) ethanol, the amino acid nitrogen content had reached0.81%. And then make enzyme inactive at the temperature of100C for20min. by orthogonal experiment to optimize the process of flavoring, the optimized conditions were obtained as Hollows:the amount of dry miso was3.0%(W/V). the amount of rice wine was6.0%(W/V), the amount of compound spices were0.3%(W/V). sensory evaluation score was8.44points. Through the single factor experiments, the optimized conditions of hot air drying process were obtained as flollows:drying temperature was60℃, drying time was4.5h. Physical and chemical testings of the final product were as follows:the moisture content was8.55%. protein content was26.82%. fat content was35.43%. salt content was4.19%. solubility was93.78g/100g. bulk density was0.43g/mL. which were similar to the control red fermented sufu powder. The final product adjusts to industry standards of sufu powder and the salt content is lower than the control powder (salt content was6.52%).After the sensory evaluation.flavor and microtexture testing.the texture.taste and flavor of products.and other indicators are all of good acceptability, which verifies the feasibility of experimental plan to develop characteristic flavor sufu powders. This study laid the foundation for industrial production of rapid fermentation method to develop low-salt sufu powder.