Study On Fermentation Conditions Of Sweet Flour Paste With Coupling Multi-strains

Sweet flour paste is traditional seasoning for a long history. Most of the small factory continue to using the traditional fermentation methods with natural inoculation. Quality of sweet flour paste is difficult to be guaranteed, because of being affected by environmental microorganisms and its long production cycle.1. The optimum conditions of making kojiThe saccharifying enzyme vigor as the index, optimized the temperature of making koji, the humidity of making koji, the time of making koji, the ratio of major material and auxiliary material(flour and bran) by single factor experiment and orthogonal experiment, determined the optimal conditions. Results showed that the best conditions of making koji by Aspergillus oryzae: the temperature was 28℃, the humidity was 90%, the cultivated time was 48h, the ratio of Flour and bran was 9:1; The best conditions of making koji by Aspergillus niger and Rhizopus: the temperature was 32℃, the humidity was 90%, the cultivated time was 48h, the ratio of flour and bran was 9:1.2. The optimum technique of fermentationThe content of reducing sugar and amino nitrogen and the relish as the index, optimized the conditions of fermentation of the temperature of fermentation and the time of fermentation and the concentration of salt and the ratio of quality of mixed strains and the time of added active dry yeast and the additive amount of added active dry yeast by single factor experiment and orthogonal experiment. Results showed that the best technique of fermentation: the cultivated time was 25d, the temperature was 45℃, the concentration of salt was 10%, the ratio of completed koji (the ratio of Aspergillus oryzae and the mixed of Aspergillus niger and Rhizopus), after ten days added the active dry yeast, the additive amount was 1.4%.3. Appropriate sterilization temperature of the tentative explorationThe content of reducing sugar and amino nitrogen, sensory evaluation, the type of volatile flavor substances and the relative content as evaluation index. Used the solid phase microextraction (SPME) conditional processing and the gas-MS analysis (gc-ms), compared the different temperature of sterilization for the influence of quality of sauce. The results show that the sterilization temperature reached 72℃, the content of reducing sugars and amino nitrogen obviously decreased, When sterilization temperature reached 76℃, the sauce slightly tasted bitter, the sterilized product of sweet sauce of the quantity of volatile compounds and the relative contents were obviously reduced. Compared with other sterilization temperature (68℃, 72℃74℃76℃), When the sterilization temperature was 70℃, the quantity of volatile compounds and relative content in sample were slightly higher. Comprehensive consideration, when the temperature of sterilization was 70℃. the content of reducing sugar decreased 5.2%, the content of amino nitrogen decreased 4%.