Research On Effect Of Lactobacillus On Beef And Chicken Mixed Meat Fermentation Property

Fermented meat products could get special flavor, appealing color, texturefeatures and a longer shelf life by microbial fermentation. In the process offermentation, artificial inoculation of microbial starter cultures has played a centralrole. In order to effectively control the quality characteristics and the change tendencyof microorganism of fermented meat products during the fermentation process, thisarticle mainly researched the effect of fermentation conditions (salt concentration,microoganism inoculation level, ratio of microoganism and fermentation temperature)on the mixed meat quality properties and the change of microorganism. Optimized theoptimum fermentation conditions by the response surface design methodology andevaluated the effect of fermentation conditions on the number of microorganisms.1. Through the study of the fermentation characteristics of plant lactobacillus andpediococcus pentosaceus, and the effect of spice on lactic acid bacteria growth abilityand the ability to produce acid, the following conclusions were included:(1) Both ofplant lactobacillus and pediococcus pentosaceus had strong ability to produce acidand can tolerate6%salt concentration,150mg/kg nitrite, optimum growth pH valuerange were5.5to6.5, optimum growth temperature range were30-40℃, so theywere suitable for mixed meat starter culteres.(2) Chili powder had a promoting effecton the growth of these two strains. Plant lactobacillus and pediococcus pentosaceushad strongest acid produce capacity when the chili powder content was0.7%,0.5%respectively. Pepper had a promoting effect on the growth of two strains. The cellconcentration reached its maximum when the pepper content was0.9%. Thelactobacilluse get the strongest acid produce capacity when the pepper content was0.5%, however it had no significant impact on the ability to produce acid ofpediococcus pentosaceus. Ginger powder had a promoting effect on the growth andacid produce capacity of these two strains. The cell concentration reached itsmaximum and had strongest acid produce capacity when ginger powder content was0.9%.2Inoculated plant lactobacillus and pediococcus pentosaceus in the mixture ofbeef and chicken meat.Through the study of the effect of different fermentationconditions on the chemical properties changes (pH value, residual nitrite, total freeamino acids and protein degradation) of the mixed fermentation meat paste duringfermentation, we got these following conclusions.(1) The pH value of the mixed meatdropped to5during the30h fermentation time, the nitrite content dropped to10to20mg/kg, total free amino acid content increased and protein was degraded under thelactic acid bacteria fermentation.(2)Salt had an inhibitory effect on lactobacillusfementation. The rate of pH value descent and total free amino acid content increasedwas significantly slower, the residual nitrite content increased and protein degradationwas weaken with the increasing salt concentration.(3)The rate of pH value descent and total free amino acid content increased was significantly faster, the residual nitritecontent decreased and protein degradation was evident with the increasing lactic acidbacteria inoculation level and fermentation temperature.(4)The rate of pH valuedescent and total free amino acid content increased was increased slight, the residualnitrite content decreased and protein degradation had no obvious difference with theincreasing ratio of plant lactobacillus bacteria inoculation level.3Through the TPA experiment (cohesion, elasticity, gumminess and chewiness)of the mixed fermentation meat paste during fermentation, we got these followingconclusions.(1) With prolonged fermentation, the cohesion, elasticity, gumminess andchewiness of the fermented meat all showed an upward trend.(2) The cohesion,elasticity, gumminess and chewiness of the fermented meat all showed an upwardtrend when salt content increased from0to3%for the salting-in effect. When the saltcontent was4%, the texture index began to fall.(3) The cohesion, elasticity,gumminess and chewiness of the fermented meat all showed an upward trend with theincreasing lactic acid bacteria inoculation level and fermentation temperature.(4) Thecohesion, elasticity, gumminess and chewiness of the fermented meat all showed anupward trend with the increasing ratio of plant lactobacillus bacteria inoculation level.4Through microbiological analysis of the mixed fermentation meat paste duringfermentation, we got these following conclusions.(1) With prolonged fermentation,the total number of bacteria and lactic acid bacteria showed an upward trend. Both ofbacteria and lactic acid bacteria showed “S” type growth curve.In the first6h offermentation (lag phase), microorganism grew slowly,6-18h (logarithmic phase) theygrew fastest, at the late fermentation phase (stationary phases), the growth ratesdeclined.(2) Salt inhibited the growth of bacteria and lactic acid bacteria; the amountof lactic acid bacteria was increasing with the increasing lactic acid bacteriainoculation level and fermentation temperature; the amount of bacteria showed noobvious difference with the increasing ratio of plant lactobacillus bacteria inoculationlevel, but the amount of lactic acid bacteria was increasing.5In order to get the optimum fermentation parameter and predict the microbialnumber, we optimize the design by Box-Behnken response surface analysis. Treatedsalt concentration(X1), microoganism inoculation level(X2), ratio ofmicroorganism(X3), fermentation temperature(X4) and fermentation time(X5) as theindependent variable, sensory evaluation score as the dependent variable, theregression equation was included:Y90.841.22X10.38X20.81X31.09X40.84X50.30X1X20.30X1X30.50X3X41.07X3X50.25X4X50.93X22.01X22.52X23.23X22.32X212345According to the regression equation of the model solution, we obtainedoptimized fermentation parameters, the response surface vaule of which was thehighest: salt concentration3.29%, ratio of microoganism plantlactobacillus:pediococcus pentosaceus0.97:1, microbial starter cultures inoculation2.91%, temperature29.46°C, fermentation time27.59h. Evaluate the influence of fermentation conditions on the number of lactic acid bacteria and bacteria during fermentation processing, the regression equation of lactic acid bacteria was included:The regression equation of total number of bacteria was included:...