Study On The Microbial Flora And The Starter Culture Of Traditional Pork Cured With Soy Sauce

Traditional pork cured with soy sauce is a kind of popular traditional fermented meat productswith special flavors and local features in china.However,at present,the products are chieflyproduced by natural fermentation and processed in manual workshops,which are limited byseasons,and need a long processing cycle,with poor safety and unstable quality.By far,thereis no report on the modern processing,the changes of the microbial flora in processing,and the mechanism of fermentation and maturation about traditional pork cured with soy sauce.And also there is no special starter culture for the producaton of traditional pork cured withsoy sauce.The study is carried out under this background.The study focused on the analysis of preponderant microorganism in traditional pork cured with soy-sauce with natural fermentation,and took it as the instruction of selecting pure good zymocyte to be used in the processing,and studied scientific parameters of fermentation tocontrol it effectively,for the sake of providing theoretical basis and technological parametersfor its industrialization.The study took traditional pork cured with soy sauce as the research object,studied on itsmicrobial flora by using classical identification methods of physiological and biochemicalreactions,and then selected standard zymocyte to make starter culture of traditional porkcured with soy sauce according to the results of the microbial flora,got optimal parameters,and studied changes of microbial counts and pH value in the process of fermentation.The conclusion of the study is:1. The total number of microbe in two samples was both high,which was reach to 10~8cfu/g,and the preponderant microorganism mainly were lactic acid bacteria,followed by theyeast,and then Staphylococcus was the least.2. The bacteria from traditional pork cured with soy sauce mainly were:Lactococcus lactissubsp.Lactis,Lactobacillus brevis,Lactobacillus plantarum,Lactobacillus delbruckii,Lactobacillus casei,Lactobacillus lactis,Streptococcus agalactiae,Staphylococcusxylosus.3. The yeasts from traditional pork cured with soy sauce mainly were:Candida fennica,Hansenula Canadensis,Candida haemulonii,Zygosaccharomyces rouxii,Bullera tsugae,Hansenula anomala. 4. The capacity of acid production of L3 was the strongest among six normal Lactobacillus,the mellow fragrance and the ester fragrance produced by Y5 was the thickest among six normal yeasts,and there was no antagonism between L3 and Y5.Therefore,L3 and Y5were taken as mixed starter culture.5. The result of orthorhombic experiment showed that the best parameters of fermentationwere:Y5:L3=l:4,inoculum's size was 2%,the fermentation time was 48h in 30℃,and the addition of glucose was 0.2%6. The total number of bacteria increased obviously throughout the fermentation process,andgrew slowly after 36h.The total number of lactic acid bacteria grew rapidly in the first12h,grew stably in 12h-36h,and grew slowly after 36h.The total number of yeasts grew slowly in the first 12h,and then maintained stably after 12h.At the end of fermentation,the total number of bacteria was 9.30×10~7 cfu/g.the total number of lactic acid bacteriawas 5.30×10~7 cfu/g.And the total number of yeasts was 1.60×10~6 cfu/g.7. The pH value of fat and lean meat was reducing in the entire fermentation process.The pH value of fat decreased marginally,just from 6.60 dropped to 6.52.But the pH value of leanmeat decreased more,from 5.99 dropped to 5.72.The decrease of the pH value slowed down after 36h.