Research On Prolongation Condition And Prediction Of Shelf Life Of Fermented Pork Jerky

In recent years,research on fermented meat products has become increasingly popular.Its unique sensory properties,rich nutrition,good digestion and absorption,long shelf life and many other advantages have made it more and more popular in the market.Nowadays,fermented meat products include traditional sausages,hams,and bacons etc.Compared with foreign countries,the development of fermented meat products in our country is still in the initial stage,and there are problems such as insufficient industrialization and lack of safety guarantees.Therefore,fermented meat products need to be improved in many ways.Fermentation of pork with lactic acid bacteria to produce fermented pork jerky has not yet been available in the market.Fermented pork jerky is a new type of deep-processed meat product that applies fermentation technology to meat products.When applies microbial fermentation technology to pork,it can not only overcome the disadvantages of poor taste and single flavor of pork jerky produced by traditional techniques,but also develop a brand-new pork jerky product for the pork jerky food industry.The experiment used Lactobacillus bulgaricus to microbiologically ferment the cooked pork to make fermented pork jerky without any preservatives during the production process.The previous research results showed that compared with non-fermented pork jerky,fermented pork jerky made by fermentation improved meat quality and flavor,promoted digestion and absorption,and also increased the research value of fermented pork jerky.At present,the research which prolonged shelf life of fermented pork jerky was little,so the experiment hopes to make up for this part of the gap and provide some references for industrial production.Firstly,L.bulogaricus was employed as starter culture to make fermented pork jerky via microbial fermentation.The fermentation conditions（inoculation amount,fermentation temperature,fermentation time）and baking conditions（baking temperature,baking time）were optimized in study.Microbial indices reflecting parameters of preserved fermented pork jerky involved the microbial detection of the total number of colonies,Escherichia coli,Salmonella,Staphylococcus aureus and Shigella.Then the best conditions for prolonging the shelf life of fermented pork jerky under each condition were obtained.Secondly,the vacuum-packed fermented pork jerky was sterilized in different ways,using boiling,pasteurization,medium temperature steam sterilization,high-temperature steam sterilization,ultrasonic sterilization,and ultraviolet sterilization to sterilize the fermented pork jerky.The experiment explored the changes of microbial indicators（total number of colonies,coliforms,Salmonella,Staphylococcus aureus and Shigella）,physical and chemical indicators（p H values,water activity Aw,total volatile basic nitrogen（TVB-N）,thiobarbituric acid（TBARS））and sensory scores during storage of fermented pork jerky with different sterilization methods.Then,the prepared fermented pork jerky was vacuum-packaged in packaging bags of different materials,and the changes of different packaging materials on the physical and chemical indicators,microbial indicators and sensory scores of fermented pork jerky during the storage of fermented pork jerky were explored.Finally,the accelerated shelf life prediction method was used to predict the shelf-life of fermented pork jerky.The prepared fermented pork jerky was stored at 30°C and 40°C.The samples stored at different temperatures were sampled regularly for different storage days.Then the microbial indicators（total number of colonies,coliforms,Salmonella,Staphylococcus aureus and Shigella）,physical and chemical indicators（p H values,Aw,TVB-N values,TBARS values）and sensory scores of fermented pork jerky at different temperatures were tested and the shelf-life of fermented pork jerky at different temperatures was obtained.To sum up,by studying the production process conditions（fermentation conditions,baking conditions）of fermented pork jerky,our results revealed that the optimal conditions for the storage of L.bulogaricus fermented pork jerky were a 10%inoculum,a 60 hour fermentation period,a30℃fermentation temperature,a 95℃baking temperature and an 85 minute baking time.The storage period was determined to be 18 days at 30℃,16 days longer than non-fermented pork jerky,and 14 days longer than non-optimized fermented pork jerky.In the research of sterilization method optimization,the results showed that the shelf-life of fermented pork jerky sterilized by the medium temperature steam sterilization method was longer than that of other sterilization methods,and the shelf-life can be up to 30 days at 30°C,and the sterilization effect was better than the other five sterilization methods.The degree of spoilage during storage was lower than other sterilized fermented pork jerky,indicated that this method was beneficial to the storage of fermented pork jerky.In the research of packaging material optimization,pure aluminum packaging materials were found the shelf life of fermented pork jerky was the longest,with a shelf life of up to 40 days when stored at 30°C.It can be seen that the use of pure aluminum packaging bags to package pork jerky further extends the shelf life of fermented pork jerky.The experimental results of the shelf life prediction of pork jerky were as follows:the shelf-life of non-fermented pork jerky stored at 30°C was 2 days,and the shelf-life of storage at 40°C was 1 day.The shelf-life of non-fermented pork jerky at commercial storage temperature of 20℃was predicted to be4 days by the shelf-life prediction model Q₁₀.The shelf-life of fermented pork jerky at 30℃was40 days～44 days,and the shelf-life at 40℃was 21 days～23 days.The shelf-life prediction model Q₁₀ predicted that the shelf-life of fermented pork jerky at 20℃was 70 days～92 days.It is hoped that the technological process of fermented pork jerky can be improved and basic data can be provided for industrial production.