Study On Strengthening Solid Fermentation Of Vinegar Based On Steam Explosion Pretreatment And Temperature Regulation

In recent years,solid state fermentation（SSF）has shown great potential in resource utilization and biological process development.Chinese traditional vinegar mostly adopts open solid-state fermentation process.This study proposes a new process that applies steam explosion technology to the solid-state fermentation process of vinegar to clarify the impact of steam explosion treatment of substrate on vinegar fermentation process,At the same time,through the establishment of server and temperature field model,the process of temperature feedback turning fermented grains is realized.Through the combination of the two methods,the efficiency of vinegar solid-state fermentation was improved.It lays a foundation for the stable production of vinegar.The fermentation experiment showed that the total acid production rate of each treatment experimental group was higher than that of the untreated experimental group in the acetic acid fermentation stage.The most significant was that when the steam explosion condition was 1.5mpa-2min,the total acid production rate was 0.443 g/100g cupei/d,which was 17.523%higher than that of the untreated experimental group.At the same time,the bacteria had the best growth state.The abundances of acetic acid bacteria and lactic acid bacteria were 10^5.139CFU/100g cupei and 10^5.055 CFU/100g cupei,respectively.The reasons for the improvement of fermentation efficiency were explored from the aspects of nutrient composition and mass transfer pores.The results showed that when the steam explosion treatment condition was 2 MPa-3 min,the specific surface area of wheat bran was the largest,which was 0.60 m²/g,the pressure increased from 1 MPa to 3 MPa,and the maintenance time extended from 60 s to 180 s,the fat dissolution of wheat bran gradually increased from 1.44%to 3.58%,increasing by 2.5 times;The starch dissolution increased from 14.72%to 19.63%,increasing by 1.33 times;The solubility of wheat bran protein increased from 8.2%to 20.41%,an increase of 2.5 times.After pretreatment,the dissolution and porosity of nutrients in bran were improved,which was more conducive to the growth and metabolism of bacteria.To sum up,the effectiveness of steam explosion pretreatment for vinegar fermentation has been confirmed.It is necessary to further build an efficient fermentation process based on pretreatment-real-time temperature feedback mashing process.The fermentation cloud server program is developed by using Django framework and LAN.The mode of system development is mainly the design of the combination of client and server.The temperature data on the production site is transmitted to the cloud server in real time.The mobile end and PC end can manage and remotely monitor the fermentation temperature through the cloud server.At the same time,the temperature monitoring model is established by interpolation method and dynamics method,Combining the two methods can quickly show the temperature distribution of vinegar fermented grains in the fermentation process and realize the process of temperature feedback.Therefore,the on-line monitoring of temperature and the simulation results of temperature field can provide scientific data and effective means for the realization of intelligent fermented grains.