Research On Screening And Fermentation Optimization Of Fermented Bacterial Strain Of Rice Steamed Sponge Cake, Analysis Of Aroma Composition

This thesis regards rice steamed sponge cake in traditional Hubei as the research object,utilize classical physiological biochemistry,of microorganism to appraise the method,let competent research to ripe rice microbial bacterial strain department of thick liquid;Take the microbial bacterial strain of advantage among them is as a basis,select fine bacterial strain use rice steamed sponge cake for ferment,study the quality of the fermented rice steamed sponge cake of bacterium with compounding of fermented rice steamed sponge cake of the single bacterium and construct the characteristic and aroma composition.This research is in the understanding rice steamed sponge cake microorganism strain foundation,screens the rice steamed sponge cake the superiority bacterial strain,produces has the Hubei peculiar taste,the quality stable,the safety and health rice steamed sponge cake.The main research content and the result are as follows:1.Separation,purification produce 3 lactic acid bacteria L1,L2,L3,5 yeast Y1,Y2, Y3,Y4,Y5 in old thick liquid,through appraisal,these 3 lactic acid bacteria are Lactobacillus casei;Y1,Y2,Y4,Y5 are Brettanomyces anomalus;Y3 is Brettanomyces claussenii.2.Through carry on research to 3 lactic acid bacterial strain and 5 performance of yeast,confirm lactic acid bacterial strain L3 reply and mixing one of the bacterial strain for rice steamed sponge cake fermented pharmaceutical,the bacterial strain Y4 of yeast, for the main fermented bacterial strain of fermented pharmaceutical of rice steamed sponge cake.3.Test the use of central composite design and response surface methodology,using statistical software Design expert on one yeast fermentation process to optimize the conditions,the yeast fermentation process of the single regression equation prediction model:y=0.88-0.064~*A-0.055~*B-0.007412~*C+0.084~*A~*B-0.013~*A~*C+0.014~*B~*C -0.068~*A~2-0.074~*B~2-0.061~*C~2.Optimize the process conditions:10%increase in plasma volume,fermentation temperature 30℃,fermentation time 15h.The optimum process conditions,the flexibility value of 0.864±0.011. 4.Test the use of central composite design and response surface methodology, statistical software Design expert with mixed strains of conditions to optimize the fermentation process has been mixed strain fermentation equation regression prediction model:y=0.76-0.045~*A+0.007886~*B-0.079~*C-0.024~*D+0.004345~*A~*B-0.005067~*A~*C -0.003937~*A~*D+0.046~*B*C+0.029~*B~*D+0.032~*C~*D+0.062~*A~2-0.035~*B~2 -0.019~*C~2-0.040~*D~2.Optimize the process conditions:bacteria ratio of 1.5:1,a 10%increase in plasma volume,fermentation temperature 35℃,fermentation time 15h.The optimum process conditions,the flexibility value of 0.79736±0.033.5.The use of SPME-GC-MS method,samples of different characteristics of flavor study results show that the mixed strains(Y4:L3=1.5:1) in the next 10 percent of pulp, temperature 35℃,fermentation time of fermentation.conditions for 15h obtained under the characteristics of rice steamed sponge cake the most flavor.