Proteolysis Of Lactic Acid Bacteria Effect On Characteristics Of Lamb Dry Fermented Sausage

To explore the effect of proteolytic ability of lactic acid bacteria on the quality of dried lamb meat,In this study,68 strains of lactic acid bacteria isolated from our laboratory were selected to have a strong proteolytic ability and excellent performance of lactic acid bacteria strains as a fermentation agent for mutton fermented sausages,After producing mutton dry fermented sausage microbiological indicators,physical and chemical indicators,total protein,volatile base nitrogen,amino acid nitrogen,free amino acids,etc.of sausages during processing and storage were tested.The results showed that 2 strains of lactic acid bacteria capable of decomposing specific proteins were screened out of 68 strains of lactic acid bacteria isolated from this laboratory.: X19-2B and X19-2D.Salt tolerance of X19-2D,growth at p H 4.5,growth at 4°C and 15°C,and acid production in different media were better than X19-2B;The ability of X19-2D to degrade myofibrillar proteins is stronger than that of X19-2B at p H6.5.Taking the above characteristics into consideration,X19-2D is preferred as a starter for mutton dry fermented sausages.Lactobacillus X19-2D was used as a starter for the processing of dry lamb fermented mutton(X19-2D group)and commercial starter(Hansen group)and natural fermentation(natural group)as the control group.The total number of colonies in the X19-2D group at one month of processing and storage was lower than the other two groups;at the end of fermentation and storage for one month,the number of lactic acid bacteria in X19-2D group was significantly higher than other two groups(p<0.05);At the end of the fermentation,the p H value of the X19-2D group was lower than that of the natural fermentation group and higher than the Hansen group,and the difference was significant(p<0.05).At the end of processing,the Aw of the X19-2D group was higher than that of the natural group;the a* values of the Hansen group and the X19-2D group were higher than the natural group;the hardness of the X19-2D group was lower than the Hansen group was higher than the natural group.At the end of processing and storage,the TVB-N content in the X19-2D group was significantly lower than that in the other two groups(p<0.05).The amino acid content of X19-2D group at the end of processing was significantly higher than other two groups(p<0.05);the total free amino acid content of each group during processing and storage was: X19-2D group> natural group> Hansen group,and the free amino acid content of X19-2D group is basically higher than the other two groups.Conclusion: A strain of lactic acid bacteria X19-2D with strong proteolytic ability can be selected from 68 strains isolated from the laboratory as a starter of sausage;X19-2D can reduce the total number of bacteria,p H,TVB-N content in sausages;increase the number of lactic acid bacteria,a* value,amino nitrogen in sausages,and proteolysis of X19-2D has increased the content of free amino acids to a certain extent and improved the quality of mutton dry fermented sausages.