Screening Of Nitrite Degrading Lactic Acid Bacteria And Their Application In Fermented Lamb Sausage

Fermented sausages are highly favored by consumers due to their good nutritional value and long shelf life.Nitrite is an essential additive in fermented meat products,and excessive residue can cause food safety hazards.This study screened lactic acid bacteria with good nitrite degradation ability and fermentation characteristics from traditional fermented foods in Inner Mongolia,and applied them to lamb fermented sausages to clarify their effects on nitrite residue,quality characteristics,and microbial community structure.The experimental results are as follows: 1.The microorganisms in traditional fermented foods in Inner Mongolia were isolated and screened,and the strains R1-1-1and YBP-2 had nitrite degradation rates higher than 85%.They were identified as Lactobacillus plantarum.The fermentation characteristics of two strains of bacteria were studied,and the results showed that after 24 hours of cultivation,the pH value of the fermentation broth decreased to below 3.65.At pH 3.5,NaCl concentration of 9%,NaNO2 concentration of 150mg/Kg,and temperature of 42 ℃,the bacterial density was relatively high.2.The processing of lamb sausages was carried out using strains R1-1-1and YBP-2 as fermentation agents,with naturally fermented sausages as the control group(CK group).In the fermented lamb sausage with added nitrite(100mg/kg),the degradation rates of nitrite in the R1-1 and YBP-2 groups were 87.28% and 87.54%,respectively.The number of lactic acid bacteria reached 108CFU/m L,the pH was maintained below 4.5,and Aw was lower than 0.75,all of which were significantly better than those in the CK group(P<0.05).The microbial community structure was determined and it was found that the Firmicutes and Lactobacillus plantarum were dominant genera in the R1-1 and YBP-2 groups of sausages,and significantly higher than those in the CK group(P<0.05).In summary,the two strains of Lactobacillus plantarum screened have good nitrite degradation ability and fermentation characteristics,effectively improving the nutritional value and safety of sausages.This provides a theoretical basis for the development and safe application of fermented sausages in the industry.