| Chilled pork has the advantages of rich nutrition,convenience and safety,good color and taste,and is the consumption mainstream of fresh meat products in China.Its high water content and comprehensive nutrients make it easy to grow microorganisms in the process of circulation,which have an immediate impact on product sales and business economic benefits.Therefore,it is of great significance to adopt practical and engineering preservation techniques to prolong the shelf life of chilled meat.In this study,chilled pork was used as the research material and was stored at 4?.Before storage,high-oxygen packaging with different oxygen content and vacuum packaging which combined with compound preservative or active films were used to preserve chilled pork.The preservation effect of compound preservation packaging technology on chilled pork was studied.The main results are as follows:?1?The effect of high-oxygen and vacuum packaging on the preservation of chilled pork.The chilled pork was respectively packaged with high-oxygen packaging?65%,70%,75%,80%?,vacuum packaging and air packaging,and measured the changes of quality indexes of meat samples during storage to evaluate the preservation effect of high-oxygen packaging with different oxygen levels and vacuum packaging on chilled pork.The results showed that both high-oxygen packaging and vacuum packaging improved meat quality.The high-oxygen packaging significantly improved the meat color,but at the same time led to the deepening of the degree of lipid oxidation,of which the ratio of 70%O2/20%CO2/10%N2 had a better preservation effect on the chilled meat.The effect of vacuum packaging on the inhibition of the growth of TVB-N and microorganisms was better than that of high-oxygen packaging,but it was not conducive to the good appearance of flesh color,and the juice loss was more serious.The shelf life of chilled pork was prolonged by 4 days and 6 days respectively by high-oxygen packaging and vacuum packaging.?2?The effect of compound preservative on chilled pork with modified atmosphere packaging.Natural preservatives?-tocopherol,tea polyphenols,chitosan were combined to preserve chilled pork in 70%O2/20%CO2/10%N2 high-oxygen packaging and vacuum packaging respectively.Used TVB-N value of meat as examining index,identified the most appropriate ration of mixed preservative through the Box-Behnken center combination experiment design and response surface analysis,and then the preservation effects of chilled pork with mixed preservative was studied.The results showed that the optimum ratio of preservative was 0.01%?-tocopherol,0.20%tea polyphenol and 1.81%chitosan with high-oxygen packaging,and 0.006%?-tocopherol,0.250%tea polyphenols and 1.000%chitosan with vacuum packaging.Compared with the untreated control group,the optimal ratio of the compound preservative in the treatment of chilled pork had an obvious preservative effect,which extended the preservative period of meat samples to 18 days and 28days respectively.?3?The effect of active films on vacuum-packed chilled pork.Used low density polyethylene as base material,?-tocopherol as active substances,and diatomite as inorganic filler for preparation of active packaging films,and explored the effect of diatomite addition on the release property of?-tocopherol in the active film and the preservation effect of different active films on vacuum-packed chilled pork.The results showed that adding diatomite reduced the release rate of-tocopherol in the active film as compared with no diatomite.When the amount of diatomite added was 1%3%,the release rate was ranked as 3%>1%>2%..The?-tocopherol active films significantly delayed the increase of TVB-N and TBARS in chilled pork,improved the color of meat and reduced the loss of juice,but had little effect on the pH value and the total bacterial count.When the additive amount of diatomite in the active films was 1%,it had the best preservation effect on the meat samples,and the preservation period of the meat samples was extended to 30 days. |
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