Study On Production And Preservation Technology Of Fermented Pork Jerky

As a traditional Chinese meat product,pork jerky has the characteristics of high protein,low fat and convenient consumption.However,traditional pork jerky has the problems of high hardness,difficulty in chewing,and poor color.Fermented pork jerky made by inoculating fermention can not only improve the stability,safety,taste,flavor and nutritional value of the product,but also prolong the shelf life of the product.Therefore,in this paper,a composite fermentation broth made of Lactobacillus plantarum and Saccharomyces cerevisiae was inoculated into the pork,and make into fermented pork jerky,focusing on the fermentation process of fermented pork jerky,the quality change process of pork fermentation process,the drying process and preservation technology of fermented pork jerky,providing a certain theoretical reference for the production of high quality fermented pork jerky products.1.Research on fermentation process optimization experiment of fermented pork jerky.(1)Through the single factor test and the Plackett-Burman test,it was found that the single factors that had a significant effect on the pork pH test results are fermentation temperature,fermentation time and inoculum of the composite fermentation broth.(2)Base on the optimal fermentation parameters obtained by single factor test were the ratio of the composite fermentation broth of Lactobacillus plantarum:Saccharomyces cerevisiae=2:1,the amount of glucose added was 1.6%,and the amount of salt added was 1.5%,the Box-Behnken response surface optimization experiment was carried out on the fermentation temperature,fermentation time and inoculum of significant influence factors.and the optimal fermentation conditions of pork were obtained:fermentation temperature was 16°C,fermentation time was 40h,and the inoculum of the composite fermentation broth was 5%,under the condition,the fermented pork had a rich flavor and a characteristic alcoholic aroma and had a good taste.2.Study on the changes of relevant quality indicator during the fermentation and after the end of fermentation of pork,and researching the quality characteristics of fermented pork jerky.Compared with the natural fermented pork without the fermentation broth,the relevant quality indicators of the pork that inoculated with the composite fermentation broth during the fermentation process and after the end of fermentation and the quality changes of the fermented pork jerky are as follows:(1)When the pork inoculated with the composite fermentation broth was in the fermentation process,its water activity(Aw)decreased at a relatively fast rate,the volatile base nitrogen(TVB-N)increased at a slower rate,and the amino acid nitrogen(ANN)increased at a higher rate.The number of lactic acid bacteria and yeast was relatively high,and the number of E.coli is significantly reduced.(2)After the end of fermentation of the pork inoculated with the composite fermentation broth,its free amino acid(FAA)content was relatively high,It was found that the muscle fibers of fermented pork were almost completely broken by observing the microstructure.(3)The hardness,elasticity,adhesiveness and chewiness of the fermented pork jerky prepared by inoculating the mixed fermentation broth were all reduced.3.Research on the technology of microwave-hot air combined drying of fermented pork jerky.(1)Fermented pork jerky In the microwave drying process,when the microwave power was 140~280W,the drying process mainly showed three drying stages:rising speed,constant speed and decreasing speed.When the microwave power was≥420W,the drying processmainly showed the two drying stages of speed increase and decrease speed,and the larger the microwave power,the shorter of the time for maintaining the constant speed drying stage,and the faster rate of the declied speed of dry water content.During the hot air drying process of fermented pork,when the hot air temperature was 50~60℃,the drying process mainly showed three drying stages:rising speed,constant speed and decreasing speed.When the hot air temperature was≥70℃,the drying process mainly showed two drying stages of increasing speed and decreasing speed,and the higher the hot air temperature,the shorter the holding time in the constant speed drying stage,and the faster the rate of drying of the dry water content.(2)The fermented pork jerky obtained by microwave drying had a low e value,poor color,low hardness and poor chewiness.The fermented pork jerky obtained by hot air drying had high hardness,poor chewiness,long drying time and low production efficiency.(3)In the microwave-hot air combined drying process,with conversion point moisture content(based on dry basis moisture content),microwave power,hot air temperature and material density as single factors,by the membership degree and weighting method,the test index redness value e value,hardness,drying time and sensory score of the fermented pork jerky were comprehensively evaluated.Taking the comprehensive score as the index,the orthogonal optimization experiment was carried out on the drying process conditions of the fermented pork jerky.The optimal fermentation conditions of the fermented pork jerky were:microwave power 420W,conversion point moisture content 0.82,hot air temperature 70°C.The density of the material was 4kg/m~2,and the fermented pork jerky produced under this condition had the highest comprehensive score.4.Study on the quality characteristics and shelf life prediction of fermented pork dry meat under different storage temperature conditions.Under the storage conditions of 17°C,27°C and 37°C,the pH of the dried pork was decreased first and then increased with the prolongation of storage time.The brightness value L*and sensory score showed a decreasing trend.The TBARS value of the corrupted indicator of fermented pork was increasing with the storage time,the higher the temperature,the faster the rate of increase.The zero-order and first-order kinetic models were used to fit the variation rule of fermented pork jerky quality index TBARS,and found that the first-order dynamic regression coefficient∑R~2(2.963)>zero-order dynamic regression coefficient∑R~2(2.696).Therefore,the first-order kinetic model had a higher degree of fit,and combined with the Arrhenius equation could effectively predict the remaining shelf life of fermented pork.