Study On Edible Quality Of Hot-Boned Pork And Construction Predictive Model Of Specific Spoilage Organisms

The hot-boned meat is carcass on sale directly which was slaughtered without fully precooling. China is the country with the most consumption of hot-boned pork."Midnight to slaughter pigs, and morning market to sell pork." In ancient times, the public had the tradition of eating hot-boned pork. In future, the fresh pork consumption structure of our country will still be the hot-boned pork. Temperature is the key factor influencing the hot-boned pork spoilage. However, in our country, study about quality changes of hot-boned pork at different temperatures is rare. Predictive microbiological technology, which through establishing a mathematical model, can rapidly predict the safety and shelf life of meat without using traditional microbial detection method, and can effectively monitor the meat microbial safety to ensure the quality and safety of meat products during production process. In the research, the differences between edible quality, pH, total volatile basic nitrogen (TVB-N) and microbe of fresh pork which was stored at25℃,20℃,15℃,10℃and4℃was compared, the SSO (specific spoilage organisms, SSO) of hot-boned pork was separated and identified, then the Escherichia coli and Pseudomonas were selected to establish mixed prediction model. The aim is to provide a theory basis for the mixed prediction model study. The contents and results are as follows:1. To check the quality of hot-boned pork in our country’s market, the fresh pork stored at25℃,20℃,15℃,10℃and4℃was compared the differences between edible quality (including cooking loss, shear force and meat color), pH, TVB-N and microbe. The results showed that the fresh pork stored at25℃,20℃and15℃had the red color, but high shear force value and poor edible quality. In around36h and48to72h, the fresh pork stored at10℃and4℃, which had great edible quality, owned good tenderness, fresh red colour, less microbe amount; within48hours, compared with stored at4℃,the fresh pork stored at10℃had no differences in cooking lose, meat color (L* value and a*value) and TVB-N, while it owned better tenderness.2. The SSO of hot-boned pork was separated and identified. Enterobacteriaceae, Pseudomonas and lactic acid bacteria were the SSO of hot-boned pork, and strains of Escherichia coli and Pseudomonas was separated and identified.3. Escherichia coli and Pseudomonas was selected to establish the mixed prediction model. The results showed that the growth curves of Escherichia coli and Pseudomonas at10℃,15℃,20℃, and25℃were finely described by modified Gompertz equation, the R2was0.998,0.999,0.995and1.000, respectively. The influence of temperature on μmax and Lag was well described by Belehradek model, the R2was0.970and0.923, respectively. The temperatures of13℃and22℃were applied to test the reliability of the model, which showed that the mixed prediction model was reliable.