Effect Of Preservation Treatment On The Application Of Growth Prediction Model Of Spoilage Microorganisms

Fresh duck meat is rich in nutrition and favored by consumers.In recent years,the proportion of fresh duck meat in the market has increased sharply,which has a good development prospect and market potential.Due to microbial proliferation in the process of slaughtering,processing and cold chain transportation of duck meat,as well as imperfect conditions and equipment in actual production,the quality of fresh duck meat deteriorates,resulting in greater economic losses and even food safety problems.Based on the actual production,processing and transportation environment,this study carried out the research on the quality change of fresh duck meat products,and clarified the change rule of the quality of fresh duck meat products.Furthermore,the growth prediction model of spoilage microorganisms in fresh duck meat was constructed repeatedly,in order to provide theoretical support for the development of quality control technology of fresh duck meat products and microbial control in the actual production process of enterprises.The main research results are as follows:(1)Based on the actual production and processing process of enterprises,the quality change law of two groups of fresh duck meat products in modified atmosphere packaging and tray packaging during cold storage was studied.The results showed that the total number of colonies,Pseudomonas and lactic acid bacteria of fresh duck meat products in modified atmosphere packaging increased significantly during storage at 4℃,and the effect of preservation treatment on lactic acid bacteria was weaker than that of Pseudomonas.TVB-N increased significantly and sensory score decreased significantly with time.However,the color difference of duck meat did not change significantly,and the p H value tended to be stable as a whole;The shelf life of the products in non-reduced bacteria group and reduced bacteria group was 9 d and 15 d,respectively.The changes of fresh duck meat packaged in trays during cold storage are similar to those of modified atmosphere packaging,and the shelf life of products treated with reduced bacteria group and non-reduced bacteria group is 10 d and 14 d respectively.The fresh-keeping methods adopted in this study have good freshkeeping effect.(2)Construction of the first-order model of microbial growth during storage of fresh duck meat products.The modified Gompertz model,Baranyi model and Huang model were used to construct the primary growth models of Pseudomonas and lactic acid bacteria in fresh duck meat products at 4℃,10℃,15℃,20℃ and 25℃.The results showed that Gompertz model and Baranyi model could better reflect the growth of Pseudomonas and lactic acid bacteria at 4-25℃ Baranyi model has the best fitting effect in the construction of Pseudomonas and Lactobacillus models of six batches of fresh duck meat.(3)Construction and optimization of microbial secondary model of fresh duck meat products during storage.The sub-square root model and Huang sub-square root model were combined with modified Gompertz and Baranyi models to describe the effect of temperature on the maximum specific growth rate.The results show that the two secondary models can describe the influence of temperature on the maximum specific growth rate in the process of model optimization.By comparing the fitting degree and fitting parameters of the models,it is found that the combination of Baranyi model and Huang sub-square root model has the best fitting degree.The combined preservation treatment of chlorine dioxide and kojic acid used in the study has a good fitting effect on Pseudomonas and lactic acid bacteria models.