Screening And Identification Of Lactic Acid Bacteria To Substitute Nitrite Color Protection From Fermentation Meat

Color is the important sensory characteristics of the meat and meat products,which is the decisive factor affecting the behavior of consumers to buy.Nitrite has not only antibacterial,antioxidant and flavor-enhancing effects in meat products,but more importantly,has the effect of improving the color of meat products,and is used as a meat coloring agent.However,due to nitrite own "toxicity" and the potential carcinogenicity,it has seriously threat to human health,so looking for alternative nitrite coloring agent is solution to solve the nitrite problem of the meat industry.Chinese traditional fermented meat products were much welcomed by the vast number of consumer consumers due to its unique flavor and nutritional value.Traditional fermented meat products are produced by the natural fermentation of their own microbes,which contain a large number of beneficial bacteria,in particular,contains a large number of lactic acid bacteria.Lactic acid bacteria is a kind of probiotics,the human body has a variety of health functions and special physiological activity.Therefore,the traditional fermentation of meat products is the study,the development of a variety of different functions of meat fermentation agent of the important biological resources.In this paper,lactic acid bacteria with excellent coloring effect and excellent fermentation characteristics were screened from the traditional fermented meat products,and the germinated bacteria were identified by physiological and biochemical and molecular biology methods.Then,the lactic acid bacteria were identified in the meat emulsion To achieve the purpose of alternative nitrite color protection,to reduce the amount of sub-acid in meat products for the purpose of the future lactic acid bacteria fermentation method to replace the meat in the nitrite color protection to provide the original strains and basic research data.Below are key research findings:1.coloring lactic acid bacteria separation,screening resultsIn this paper,four different natural fermented meat products of Niuganba,Sichuan sausage,Xuanwei ham and board duck were coated on MRS solid medium containing 3% calcium carbonate,and the Gram-positive G +),hydrogen peroxide negative,the production of calcium lamb lactic acid bacteria 166,of which cattle dry Pakistan strains,Sichuan sausage strains,Xuanwei ham strains of duck strains.33 strains of lactic acid bacteria were screened out from 166 strains of lactic acid bacteria by myoglobin plate culture and myoglobin liquid culture.Among them,the myoglobin plate culture from the 166 strains of lactic acid bacteria were screened with 69 coloring effect of lactic acid bacteria,the 69 strains of lactic acid bacteria are contained in 2mg / ml high-iron myoglobin solid culture medium at 37 ? for 24-48 h Bright red,the remaining 135 strains are brown.69 lactic acid bacteria were used to detect the color-protecting effect of myoglobin liquid culture,and 33 lactic acid bacteria with best color-protecting effect were screened out.The 33 strains of lactic acid bacteria produced bright red at 37 ?for 10 h,and the color was stable.Among them,12 strains of bovine dry bar,12 strains of Sichuan sausage and 9 strains of Xuanwei ham.Indicating that there are lactic acid bacteria in the natural fermentation of meat products with alternative nitrite,and the proportion of Lycoranic acid bacteria in different samples is different.2.Determination of Main Fermentation Characteristics of Lactic Acid Bacteria and Preliminary Study on the Transformation of Myoglobin Derivative Type.2.the main fermentation characteristics of color-protecting lactic acid bacteria According to the requirements of Lactobacillus in fermented meat products,the main fermentation characteristics of 33 color-protecting lactic acid bacteria were determined.Finally,three lactic acid bacteria with good fermentation characteristics were selected,which were numbered L2?bovine dry bar?L3?cattle dry bar?and X31?Xuanwei?.L2,L3 and X31 were reduced to 4.47,4.40 and 4.58,respectively,in the MRS medium for 24 h,and no mucus was obtained.Tolerance of 6% NaCI and 150 mg / kg NaNO₂ was carried out.Fermentation glucose was not produced.Ammonia does not produce ammonia,can inhibit E.coli and Staphylococcus aureus.The strain has excellent fermentation characteristics and meets the screening criteria for meat products.3.the color of Lactobacillus bacteria identification results The three strains were screened and identified.The three strains had good colonies,rounded,neat and slightly raised.The surface was smooth and smooth,and was gray and white.Under the oil microscope,the cells were round or pointed spherical,single or paired,Gram stain positive?G +?.Tolerance,and sugar alcohol and other physiological and biochemical tests,identification results and "Berger's bacteria identification manual","common bacterial system identification manual" comparison,comprehensive morphological characteristics of the initial results of L2,L3 and X31 three lactic acid Yersinia.The results showed that the size of L2,L3 and X31 were 1433 bp,1414bp and 1443 bp respectively.The sequencing results were compared in the GenBank gene pool.The phylogenetic tree was constructed and finally identified as fusion Weibesia,L3 and X31 for food Weiss bacteria.4.coloring lactic acid bacteria biological characteristics of the research results L2,L3 and X31 three lactic acid bacteria of the optimal growth temperature of 37 ?,the optimum pH of 6.It was found that strains L3 and X31 were more favorable than L2 in pH2 pH4,and L2 was more stable than L3 and X31 at pH 9.Both strains L2,L3 and X31 had no fat and protein degradation activity.Three strains were observed at 37 ? for 24 h,and the three strains entered the logarithmic phase from the growth stage for about 4 hours.During the incubation period of 8 hours,the medium entered the stable period of about 8 hours,,X31 in the culture 14 h into a stable period.The acidity rate of the three strains of lactic acid bacteria increased with the increase of the cell density,and the pH value of the strains L2,L3 and X31 increased at 37 ? for 24 h,especially the growth rate of the cells Period to logarithmic period is more obvious,when entering the stable phase after the pH remained stable.There was no significant difference in pH between the two cultivars,and the pH values were 4.47,4.40 and 4.58 for L2,L3 and X31 respectively.5.color lactic acid bacteria in the meat of the role of color protection Three lactic acid bacteria were prepared as color protection agent,and the meat emulsion was soaked in it for 2 min.The 100 mg / kg sodium nitrite was used as a control.The sensory evaluation and color difference test showed that the three lactic acid bacteria had good color protection,Can be used for meat products instead of nitrite color protection.