Screening And Application Of Bacteria Strains To Be Used As Meat Starters In Fermented Sausage

There are a lot of bacterium resources in natural fermented foods, and can be used to select starter cultures with excellent characteristic for fermented meat products. Isolation, purified, screening and application of fermentative microbiology from naturely fermented food ( most meat products ) had been carried out in this study. The report including several parts as follows:1.132 strains of lactic acid bacteria were isolated and purified from fermented food, their important fermentation characteristics were studied. Salt and nitrite tolerance for different strains had significant difference. Most isolates produced no gas(CO2) from glucose(74%),H2S (72%)and NH3 from arginine(77%) . Few strains were responsible for slime production. Some were no H2O2 producers (33%) and had no decarboxylase activity (48%) . About half of LAB inhibited E.coli and S.aureus. Acidification rate and acidifying capacity varied significantly for these lactic acid bacteria in different broth.2. 4 strains with excellent characteristics were selected on the basis of fermented dry sausage. The growth of 4 strains had significant difference, the effect of temperature on the growth of 4 strains were significant. Four strains were preliminary identified, R17 was Lactobacillus pentosus, P20 and P30 were Pediococcus pentosaceus, J33 was Lactobacillus sake. R17 and P20 were selected as mixed culture following compatibility tests between strains.3. 158 catalase-positive cocci were isolated and purified from traditional fermented meat products with MSA agar. 50 strains showing very high nitrate reduction according to a fast semiquantitative plate assay were selected, then according to fermentation adaptation, two cocci S15 和 S113. were selected , two strains displaying proteinase and lipase activity were preliminary identified as staphylococcus carnosus S15 和 S113.4. lactic acid bacteria with two staphylococci were mixed cultured on simulative broth medium, their relationship were studied and mixed starter cultures P20+S15 was initial selected. According to acute toxicity test , S15 are safety.5. Fermented sausage were produced with selected strains, microbial and pHysico-chemical changes were studied. Lactic acid bacteria of 4 batchs with starter culture rapidly dominateds the total microflora. P20+S15 showed significantly more staphylococci counts than other batch.. The growth of enterobacteriaceae was inhibited and they were reduced to undectectable levels after 14 and 28 day. The lowest value were reached at 3th day, then the pH values increased slightly. Aw values significantly decreased. No significant difference was found in texture between 4bacths with starters. There were significant difference in colou between different batchs, The a value of P20+S15 showed siginificantly higher than other batchs. Combined with sensory evaluation, 4 batch could be used as meat starter cultures in fermented sausage.