Effects Of Different Packaging Materials And Packaging Conditions On The Quality Of Beef Storage

In recent years,with the development of economy and the improvement of people's living standard,yield and consumption of beef have been increased generally.Thus,consumers are paying significant attention to the freshness and hygienic quality of beef.The quality characteristics and the storage of beef are quite urgent to be solved in the development of meat industry in China.In this paper,chilled beef is chosen as the experiment material,examining the effects of different gas atmosphere package and packaging materials on the chilled beef quality.And the synergistic effects of single or compound natural preservative agents with modified atmosphere packaging on cooling meat shelf life.It is order to provide theoretical support for the preservation of beef and extending the shelf life.1.Firstly,the composite bags and PVDC materials were used to study the effects of natural packaging group,vacuum packaging,modified atmosphere packaging(gas is 60%O2+20%CO2+20%N2.40%O2+30%CO2+30%N2)on the quality of fresh beef.The sensory evaluation,pH,color difference,odor determination of electronic nose,determination of TVB-N,texture related parameters,total number of colonies and detection of coliform were analyzed during the beef were kept in 0-4 0.The results showed that the different packaging materials on beef during the storage period had little influence on its quality.In the process of cold storage,pH,the content of TVB-N and the quantity of microorganism increased.Descend range of texture characteristics were different and odor varied differently.The color changed from red to brown and the sensory score was decreased.Considering the TVB-N value as a judgment index,index,natural packaging shelf life can reach 3 days,vacuum packaging shelf life can recch 6 days,modified atmosphere packaging shelf life can reach 9 days.The best combination is PVDC material with 60%O2+20%CO2+20N2%,which has a good antibacterial effect can maintain desirable color.Shelf life can reach 12 days.The packaging materials less affected the quality of beef.2.Second,we studied the influence of natural preservative agents on the quality of beef in the optimistic gas condition(60%O2+20%N2+20%CO2).Some natural preservatives were chose to soak beef,such as nisin,natamycin,lysozyme,nisin+natamycin,nisin+ lysozyme,natamycin+ lysozyme,and then stored in two kinds of packaging materials(PVDC,composite bags)at 0-4 ?.The microbial indexes of cold fresh beef(total bacterial count,coliform),TVB-N,pH,color and TPA(hardness,adhesiveness,elasticity,chewiness),sensory evaluation indicators were analyzed.During cold storage,the pH value,TVB-N and microorganism increased gradually,and other beef quality indexes changed differently.Using TVB-N as the indicator of blank samples shelf life were up to 12 days.There was no significant effect between nisin and natamycin Adding nisin,natamycin,natamycin + lysozyme,lysozyme + nisin can make the shelf life to 15 days.The best effect is lysozyme and its shelf life were up to 18 days.Short term storage packaging materials has little effect on beef quality.