Study On The Processing And Storage Stability Of Semi-dried Pork Porky

As a traditional Chinese meat food,pork jerky has a long history and rich nutritional value.However,traditional pork jerky is difficult to chew and has high hardness,which cannot meet the needs of modern consumers.Developing pork jerky with moderate tenderness and good taste has become a hot research topic.In addition,pork jerky is prone to mildew,how to control the growth of mold,and prolong the shelf life of pork jerky is an important issue that needs to be solved urgently.Based on this,kiwi protease and elastase were added in the process of making pork jerky to determine the processing conditions of semi-dried pork jerky,the formula was optimized,the molds in the mildewed pork jerky were separated and identified,and antifungal agents that can effectively inhibit spoilage molds in pork jerky were preliminary screened and compounded.Finally,the storage stability of semi-dried pork jerky was explored.The main experiments and results have shown as follows:(1)The kiwi protease and elastase were added in the pork jerky processing.The effects of the amount,proportion,tenderization time and tenderization temperature of the compound protease on the tenderness of the pork jerky were studied.Orthogonal test was carried out,and the optimal conditions for the tenderization of pork jerky with composite protease were as follows: the amount of complex protease(accounting for the quality of pork)was 0.05%,kiwi protease dosage: elastase dosage was 3:1,and the tenderization time was 90 min,tenderization temperature was 55°C.Comparing with the pork jerky before tenderization,the shearing force of the pork jerky after the tenderization of the complex protease decreased from 5807.37 g to 4445.07 g,the difference was significant(P<0.05).The sensory score increased from 75.03 to 83.14,which significantly improved the tenderization and sensory score of the pork jerky.(2)The formula was optimized by uniform test.The spicy pork jerky and hot spicy pork jerky were developed.The optimal addition amount of the spicy pork jerky ingredients was as follows: the total concentration of hot pepper and zanthoxylum was 20.77%,and hot pepper: zanthoxylum was 5:1,the concentration of zanthoxylum was 5.5% and the concentration of ginger was 7.55%.The optimum addition amount of hot spicy pork jerky was: 8.39%,1.00%,0.58% and 4.06% of hot powder,spiced powder,octagonal powder and ginger.(3)The molds on the mildewed pork jerky were separated and purified,and 8 molds were obtained.The six molds were identified as Aspergillus chevalieri,Aspergillus terreus and Aspergillus sp.,Penicillium sp.,Irpex lacteus and Altermaria mail.Among them,No.1,No.2 and No.3 were Aspergillus,No.4 was Penicillium,No.5 was Capsule,and No.6 was Alternaria.(4)Four kinds of fungicides which had a good inhibitory effect on the spoilage of pork jerky: polylysine,sodium dehydroacetate,natamycin and clove essential oil were initially screened.The uniformity test was used to compound polylysine,clove essential oil,natamycin and sodium dehydroacetate to study the antibacterial effect of the composite antifungal agent on 8 kinds of molds.The optimum ratio of the composite antifungal agent was: polylysine,clove essential oil,natamycin and sodium dehydroacetate were 0.011%,0.110%,0.010% and 0.003%,respectively.(5)A composite antifungal agent was applied to pork jerky.According to whether the bacterial suspension and the composite fungicide were added to the pork jerky samples,they were divided into three groups.The first group was a blank group,that was,neither bacterial liquid nor compound antifungal agent was added to the pork jerky samples,the second group was the bacteria-added group,that was,only the bacterial liquid was added to the pork jerky samples.The third group was the bacteria-preserved group,the bacterial liquid and the compound antifungal agent were simultaneously added to the pork jerky samples.The results showed that the blank group of pork jerky can not be mildewed in a short time.There was a significant difference in the number of molds between the bacteria-added group and the bacteria-preserved group(P<0.05).During the storage period of 20 days,the number of molds in the bacteria-preserved group was gradually reduced to 3.95 Log CFU/g.It shows that the compound anti-fungal agent has a good practical application effect in the prevention of mold from pork jerky.In the storage stability test of pork jerky,the pork jerky was stored at 28°C and 37°C for 60 days,and the sensory scores showed a downward trend.At 37°C storage conditions,the sensory score of pork jerky decreased faster.The TBA value did not change much during the storage period.The microbial detection showd that the total number of colonies of pork jerky products did not change much and remained within 1000 CFU/g,indicating good bacterial stability.E.coli was not detected and met national standards.Therefore,pork jerky has a good microbial stability.