The Study On The Establishment Of Prediction Model Of Shelf Life And The Technology Of Pulsed Light Preservation Of Chilled Chicken Breast Meat

This project is based on the actual production situation of the factory and measured at the factory production site.Since the process and the main equipment are the same or similar to most of the domestic slaughter and processing plants,the sampling of the factory investigation experiment is carried out at the production site and synchronized with the production process.It can provide a theoretical basis to the factory to develop practical production regulations.Shelf life prediction experiment takes the chicken breast carcass temperature of 0-4 ?,and timely sent to the factory center laboratory,were placed at 0?,4?,7?,10?,15 ?,20?,25 ?temperature microbial and physical and chemical indicators of detection.Using the microbial growth kinetics model to predict the shelf life of chilled chicken breasts at different temperatures,the quality and safety of the products can be accurately judged.The chicken breasts are used as the research object,and the bactericidal rate,shear force,dehydration Rate,?E,p H as an indicator of pulsed light sterilization techniques.On the basis of single factor experiment,the Box-Benhnken center combination design principle and response surface analysis method were used to determine the best conditions of pulse and strong light sterilization,and to prolong the shelf life of chilled chicken breasts under the condition of ensuring product quality.The results showed that.(1)Through the investigation of the present situation of microbial contamin ation of chilled chicken meat during the production process,with the extension of time,the number of microorganisms about the main contact including knives, chopping board,workers hand each 0.5h showed the trend.There were signifi cant differences in the number of microbial contamination on the surface of ch icken before and after cooling After cleaning and disinfection,the number of ini tial microorganisms in the main contact was higher for 1.6220~4.1767lg(cfu/cm~2),the microorganisms quantity of conveyor increased to 2.3045 ~2.8864lg(cfu/c m~2)in 0.5h,2.6194~3.1005 lg(cfu/cm~2)in 1h,2.5034~2.9488lg(cfu/cm~2)in 2h.The number of microorganisms in the conveyor belt after cleaning and disinfection was 0.6066 lg(cfu/cm~2),the microorganisms quantity of conveyor increased to 3.2768 lg(cfu/cm~2)in 3h,2.6666lg(cfu/cm~2)in 4h.After cooling,the number of microorganisms on the surface of chilled carved chicken breast was 1.7333 lg(cfu/cm~2),significantly lower than the number of microorganisms in the main co ntact work,and the main contact close with the cooling of the chicken breast i n the process of working,which indicated that the segmentation process had sec ondary pollution to chicken itself.The number of microbial contamination of chi cken carved breast meat and chicken carved leg meat before and after the part ition was 1.3900~1.6833lg(cfu/g)and 2.4900~2.4467lg(cfu/g),respectively.Strength en disinfection work suggests that enterprises improve the disinfection time of main contact in the process of segmentation: It is suggested that enterprises sh ould strengthen disinfection work,improve the disinfection time of main contac ts in the process of segmentation,control pollution sources,and avoid the influ ence of the two pollution on the products.(2)The first-order model(logistic equation)of the total number of colony colonies and the second-order model of the second-order model of colony at the constant temperature were better than 0.94,which could well fit the growth of the total number of colonies at different temperatures.The remaining shelf life equation of chilled chicken breast was established:SL=1/[0.01828(T+4.122)]2-[(6.8620-log N0)/[0.01544(T+10.66)]2*2.718]*{ln[-ln(5.78-log N0)/(6.8620-log N0)]-1}.As long as you know the initial colony and storage temperature conditions when cooling chicken breasts,the total number of colony kinetic models can quickly and reliably predict the remaining shelf life of 0-25 ?storage,the actual production has important guiding significance.(3)To determine the best pulse sterilization equipment parameters are as following : the pulse energy 400 J,pulse distance of 12 cm,pulse time 50 s.Under these conditions,the total bactericidal rate of colony reached 90.33%,the shear force was 2.59 kg,the water loss rate was 31.00%,color /?E was 3.46.The relative error of sterilization rate,water loss rate,shear force,color / ?E was 0.32%,3.26%,1.54% and 2.02%,respectively.According to the prediction model of the remaining shelf life of frozen chicken breasts,it can be seen that the storage rate is 0 ~ 4 ?,the initial colony value is reduced by one order of magnitude,the corresponding shelf life can be extended for 1-2 days.It indicates that the optimized equipment parameters effectively solve the factory the real problem facing.