Isolation, Screening And Application Of Lactobacillus Casei From Natural Fermented Meat Products

In this research, strains were isolated and screened from natural fermented sausages and cured meat. Their capacity of acid and enzyme production , their application in fermented sausages and fermented meats were analysed. The results were:Based on the standards of screening lactic acid bacteria) for fermented meat products, Two strains of lactic acid bacteria with excellent character were isolated and screened from natural fermented sausages and cured meat, respectively named as C67 and R6. They did not produce gas and slime,showed high acidification rate and acidification capacity.Both of them also showed high resistance to nitrite and NaCl.They were identified as Lactobacillus casei.The optimum harvest time of maximum bacteria counts of C67 in MRS broth was 10h,that time of R6 was 12h.The lowest pH within 24hours in MRS broth of C67 and R6 were respectively 4.00 and 3.97.They grew well at 25-40℃.They did not produce lipase and had weak proteolytic activity.They could not produce the biogenic amines from histidine and lysine.Physico-chemical properties and microbiological characteristics were studied during the processing of fermented sausage,sensory analysis was also done. The results showed that the pH ,Aw, moisture content dropped more rapidly and with higher proteolysis index in the groups added strains than those in the control group.There were no differences in acidity value and peroxide value between three groups. POV of two fermented groups was lower than control groups.The lactic acid bacteria of fermented groups was dominant flora during the whole processing with the maximum bacteria counts 108cfu/g, while that of the control group increased gradualy with the maximum bacteria counts 107cfu/g.The fermented groups had more welcome flavor and sour. They are suitable for Chinese people.But the surface colour of the fermented groups were worse than the control group.There were faults in single strain fermentation.Physico-chemical properties and microbiological character were studied during the processing of fermented meat,sensory analysis was also done. The results showed that the pH ,Aw, moisture content dropped more rapidly than the comtol.The lactic acid bacteria of fermented groups was dominant flora during the whole processing with the maximum bacterial number 108cfu/g, while that of the control group increased gradualy with the maximum bacterial counts 106cfu/g. The fermented groups had obvious fermentation flavor and acceptable sour.