Research On Preservative Packaging Technologies For Chilled Meat

The shelf life is one of main factors that have limited the further development of chilled meat in our country. The efficient technologies of preservative packaging is the important process that can extend the shelf life of chilled meat and ensure the high quality of goods. The paper used chilled pork and chilled goat meat as the material, including three parts: The effects of different packaging on chilled pork qualities were studied; Focused on the applications of preservatives and packaging in the preservation of chilled pork; Research on effects of different headspace to meat volume ratios on chilled meat qualities. Applications of hurdle technologies were to improve disadvantages of use of packages alone, and analyzed advantages and disadvantages of different combinations.Part I :The effects of vacuum packaging and modified atmosphere packaging (20%CO₂/80%O₂/0%N₂,40%CO₂/40%O₂/20%N₂,40%CO₂/60%O₂/0%N₂,60%CO₂/20%O₂/20%N₂) on microbial growth, TVB-N value, TBARA value, percentage of weight loss and sensory quality of chilled pork were analyzed. The result showed :The preservative effects of MAP(60%CO₂/20%O₂/20%N₂) were the best in different packaging methods, and shelf life was up to 12 days.There was higher percentage of weight loss in vacuum packaging; The chilled meat in MAP(20%CO₂/80%O₂) maintained better color sensory quality in shorter storage time.In MAP, when the percentage of CO₂ is higher than 20%, the effect of inhibitory bacteria become better with the increasing of CO₂ concentration ,but in excess of 40%, no similar result.Part II :Chilled pork samples was dipped in preservatives(0.3%TP, 0.3TP+1%Vc, 1%HAC+1%Ch, 0.3%TP+1%HAC+1%Ch),then respectively packaged with VP, high O₂ MAP (20%CO₂/80%O₂) and low O₂ MAP (60%CO₂/20%O₂/20%N₂). The result showed:The preservative effects of combination packaging methods with preservatives were excellent to packaging alone. In three packaging methods, 0.3%TP+1%HAC+I%Ch showed marked inhibition of bacteria, especially, in VP and high O₂ MAP ,shelf life of chilled pork was extended to 15 days later.In high O₂ MAP, TP exhibited more effective antioxidation, and TBA value of chilled pork was 0.66mg/kg in day 15, without TP sample ,TBA value was up to 2.3mg/kg, and chilled pork exhibited better color sensory quality by TP, shelf life was extended too. So combination high O₂ MAP with TP showed excellent preservative effects.Vc could accelerate lipid oxidation and Ch could make color of chilled meat become bad in all packaging methods.Part III: This part respectively used chilled pork and chilled goat meat as sample, which were packaged in high O₂ MAP (20%CO₂/80%O₂) and headspace to meat volume ratio were 3 :1,2: 1,1:1. This trial showed:The preservative influence of different headspace to meat volume ratio on chilled goat meat was more significant than chilled pork.The 3 : 1 headspace to meat volume ratio was most effective at inhibiting bacteria both chilled pork and chilled goat meat ,but showed no significant differences between 3 : 1 and 2 : 1 ratio, Thinking about that larger volume of the 3 : 1 ratio could lead to increase material and distribution cost and so on., therefore, the 2 :1 ratio was more appropriate for practice.