Isolation, Screening And Application Of Lactic Acid Bacteria From Fermented Sausages

Fermented meat products have long history, but it belongs to natural fermentation before. Just because of the uncertainty and uncontrolable property of natural fermentation, more and more people arc inclined to use pure microbe cultures applied to the modern process to control fermentation. Moreover, the fermentation ensures product safety and stability of quality. Fermentation of meat product can not only increase digest absorption ration of product, but also give the product special flavor and prolongs its storage time. Thus, isolation, purified, screening and application of fermentative microbiology from Ukrainian fermented sausage had been carried out in this study. The report includes several parts as follows:6 strains (L1, L2, L3, P1, P2 and P3) of lactic acid bacteria were isolated and purified from Ukrainian fermented sausage, their important fermentation characteristics were studied. Salt and nitrit tolerance for different strains had significant difference. Most isolated strains produced no gas (CO₂) from glucose(L1, L3, P2 and P3); all isolated strains produced no H₂S, H₂O₂, decarboxylase activity and NH₃ from arginine; all isolated strains were responsible for slime production; 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.4 strains (L1, P2, P3 and L3) with excellent characteristics were selected on the basis of fermented 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: L1 was Lactobacillus plantarum, P2 and P3 was Pediococcus pentosaceus, L3 was Lactobacillus acidlophilus. L1 and P2 were selected as mixed culture following compatibility tests between strains.Fermented sausages were produced with selected strains and Chinese fermented meat products, microbial and physico-chemical changes were studied.Optimum proportion of Lactobacillus plantarum and Pediococcus pentosaceus were gained by orthogonal test L₉ (3⁴). The result showed that, the optimum proportion of Lactobacillus plantarum and Pediococcus pentosaceus was 1:1, the viable cell counts was 10⁷cfu/g, temperature of fermented 30°C, RH was 85% or 90%.During fermented process, the total of free amio acid and fat acid do not vary obviously, but Thr, Ala, Glu, Ile, Leu, Val etc increase obviously in the trial; In the free fat acid, C_18:1 reduces, C_18:2 and...