Growth Kinetics Model And Shelf Life Prediction Of Specific Spoilage Bacteria In Sacheted Sauced Duck Clavicle

Sauced duck is rich in nourishment and flavor,and deeply loved by our people,which is popular all over the country in recent years.Sauced duck has low processing temperature and high moisture content,so it is susceptible to bacterial contamination and spoilage,and a threaten of the comsumers'health.At the same time,it also limits the further development of sauced duck industry in China.Therefore,it is necessary to determine the specific spoilage organism,and establish a fast and effective shelf-life prediction method for sauced duck products,to ensur the comsumers'health and promote the sustainable development of sauced duck industry in China.This research takes sacheted sauced duck clavicle as the research object,and uses the 16S r RNA gene metagenomic method to study the change of microbial community composition,and combines with the change of quality to determine the specific spoilage bacteria.On this basis,establishs the growth kinetics model of the specific spoilage bacteria.Furthermore,eatablishs the shelf life prediction model in sacheted sauced duck products storaged at normal temperature.The contents and results are as follows:1.Study on the change of microbial community during storage of sacheted sauced duck clavicle.In this study,high-throughput sequencing method based on Ion S5^TMXL conbined with the16S r RNA gene metagenomic method is used to analyze the changes of microbial community composition in the sacheted sauced duck clavicle storaged at 4°C and 25°C.The results showed that with the increase of storage time,the diversity of microbe in the sacheted sauced duck clavicle decreased gradually and the community structure tended to be simple.In the late of storaged at4°C,dominant microorganism are Cobetia(25.9%),Psychrobacter(22.4%)and Weissella(13.5%).In the late of storaged at 25°C,dominant microorganism is Weissella(67.9%).2.Determination the specific spoilage bacteria of sacheted sauced duck clavicle.The results showed that the specific spoilage bacteria is Weissella storaged at 4°C to 35°C,by analazing the physicochemical,sensory and microbial indexes of the sacheted sauced duck clavicle storaged at4°C,25°C and 35°C.By analyzing the linear relationship between Weissella and the total plate count,the minimum putrefaction of Weissella is 3.188 lg(CFU/g).3.Microbial growth kinetics models for the specific spoilage bacteria and shelf life prediction model of sacheted sauced duck clavicle.Logistic model is used as primary model to fit observed data,and Belehradek model is used as secondary model.On this basis,eatablishs the shelf life prediction model in sacheted sauced duck clavicle storaged at 15-35°C:SL={-ln[(7.368-N₀)/(3.188-N₀)-1]}/?_max+?.The results show that the relative error of the model is less than 10%,which can be used to predict the shelf life of sacheted sauced duck clavicle.