Effects Of Lactobacillus Plantarum CM25 On Microflora Community Structure And Sensory Quality Of Fermented Sausage

Two strains of Lactobacillus Plantarum isolated from traditional fermented meat products were used to produce fermented sausage.The effects of different starter cultures(CM25 and X31)on the quality of fermented sausage were studied with natural fermentation(ZR)as the control group.From the basic indicators,the p H value of the fermentation group(CM25,X31)decreased rapidly,and the p H value,Aw,and water content decreased first and then tended to be stable.The change in sausage texture was manifested as the increase in hardness,chewiness,and the decrease in elasticity.The TBA value of sausage added with starter cultures(CM25,X31)was lower than that of ZR group.The CM25 group compared with the other two groups,the overall quality characteristics of sausage are better.In terms of flavor,the response values of electronic nose sensors(W5S,W1 S,W1W,W2 S,W2W)in the ZR group were lower than those in the CM25 group and the X31 group,indicating that adding lactic acid bacteria helps to form more alcohols,aldehydes,and acids.GC-MS analysis showed that the ZR group had the least kinds of flavor substances and low content.The CM25 group had the largest number of volatile flavor compounds(43 species)in the mature stage,and the contents of ethanol,benzaldehyde,benzaldehyde,3-methyl-1-butanol,heptanal,n-hexanol,and hexanal were relatively high(212.65,38.89,32.07,4.90,5.46,4.62,21.19 AU × 106 / g),indicating that the decomposition of carbohydrates,amino acid metabolism,and fatty acid degradation were rapid in sausage.The contents of ethyl butyrate,ethyl hexanoate,ethyl 2-hydroxypropionate and ethyl heptanoate in the sausages of group X31 were relatively high(56.42,187.17,92.06,and 16.24 AU × 106 / g),and the accumulation of esters was relatively high,which played an important role in the formation of sausage flavor.From the perspective of flora structure,Firmicutes in CM25 and X31 groups were dominant,with relative abundances of 99.04 % and 98.92 %,respectively.Lactobacillus was dominant,with relative abundances of 95.42 % and 95.60 %,respectively.Through the analysis of the structure and flavor correlation of sausage flora,it was found that there was a positive correlation between 1-octanol,undecanal,octanal,ethyl palmitate,and ethyl octanoate and other flavor substances,such as Lactobacillus,Streptococcus,Pseudomonas,Weissella,and Enterococcus,indicating that most of the genus-level bacteria would directly or indirectly use nutrients such as protein,fat,and carbohydrate to produce a variety of flavor substances while meeting the growth and metabolism of bacteria.Ethyl caproate was significantly positively correlated with Lactobacillus(P < 0.01).Ethyl caproate was a short-chain fatty acid with a low threshold,which had a significant contribution to sausage flavor.In conclusion,this study can provide a theoretical basis for the industrial development and safety application of fermented sausage.