Study On The Effect Of Apple Polyphenol To Shelf Life Of Chilled Meat In Different Packaging

In the last few years,with the transformation of people's ideal in consuming,meats consumption in our country has had the obvious constitutive change.The producing of chilled meat has had presented the strong development,but the shelf life of chilled meat has been the key aspect of limiting its development,how to extend the shelf life of chilled meat has becomed the urgent question to be solved in the chilled meat processing industry,taking the effective technology of maintaining freshness is an essential tache to keep the high quality of chilled meat.Vacuum and modified atmosphere packaging has adopted widely in our country and abroad,and the technology is relatively mature,however,a single form of packaging should not tend to get a better effect,the integrated use of several means is required.With the strength of people's consciousness in food security and nutritional requirements,the use of traditional chemical preservatives has being challenged.So many investigation in our country and abroad shows that apple polyphenols not only has excellent ability of oxidation resistance,but also has broad-spectrum antibacterial ability,which have practical significance to develop the natural preservatives and antioxidants of new type.The paper used fresh pork as raw materials,major research on antibacterial effect and oxidation resistance of apple polyphenols to the major spoilage organisms and pathogens in chilled pork,the antibacterial and antioxidant components of apple polyphenols was primarily determined by HPLC.Confirmed its effective concentration combined with single factor experiment about preserving vacuum packaging chilled pork by using apple polyphenols,find the best proportion of apple polyphenols compound with other natural preservatives by orthogonal experiments.In order to tackle the problem of discoloration of chilled pork which is in high-oxygen modified atmosphere packaging(80%O₂/20%CO₂) during storage,confirm its effective concentration combined with its antibacterial effect and single factor experiment about keeping color of chilled pork by using apple polyphenols,find the best proportion of apple polyphenols compound with other natural anti-oxidants by orthogonal experiments.The result of experiment is as follows:1.The result of antibacterial experiment of apple polyphenols shows that:Apple polyphenols have antibacterial effect to the five bacteria.The antibacterial effect to G^-(Escherichia coli, Pseudomonas fluorescens)is better than G⁺(Staphylococcus aureus,Lactobacillus),the best antibacterial effect is to Escherichia coli,and the worst is Lactobacillus.The MIC of apple polyphenols to Escherichia coli and Staphylococcus aureus is 0.02%,The MIC to Bacillus subtilis is 0.06%,The MIC to Lactobacillus is 0.08%.The best antibacterial concentration of apple polyphenols to the five bacteria is 0.1%～0.5%.The antibacterial ability of apple polyphenols is best in the circumstance of pH=5～6,and the worst is in pH=8.2.The result of antioxidant experiment of apple polyphenols shows that:The antioxidant effect of apple polyphenols to lard is worse than TBHQ,but better than VE and clove naphtha.3.The antibacterial and antioxidant components of apple polyphenols was primarily determined by HPLC,the result shows that,the sample of apple polyphenols contain(+)-catechin and (-)-epicatechin,according to literature,it may also contains chlorogenic acid or caffeic acid.Because of lacking standard samples,other components of apple polyphenols could not be determined exactly.4.The fresh keeping experiment of chilled pork by using apple polyphenols shows that:The apple polyphenols could extend shelf life of vacuum packaging chilled pork effectively,The great concentration of apple polyphenols,the better fresh keeping effect.The fresh keeping effect of 0.08%,0.1%apple polyphenols are worse than other four treated team,this is relative to the antibacterial effect of apple polyphenols.The water loss of treated team is higher than CK in the prophase of storage.The water loss of 0.5%is the highest of every treated team during the whole storage.The treated team of 0.2%,0.3%,0.4%have the best fresh keeping effect of all.According to range analysis of experiment result and the analysis of every target as a whole,the best components of compound preservatives is A₂B₃C₁D₃,0.3%apple polyphenols+0.1%Nisin+ 2%NaL+1%Chitosan.5.The color keeping experiment of chilled pork by using apple polyphenols shows that:The apple polyphenols of different concentration could restrain the increase of microbial flora counts, TVB-N value and pH value.The great concentration of apple polyphenols,the better effect.It is not The great concentration of apple polyphenols,the better color keeping effect,the best antioxidant concentration is 0.1%,it will present assistant oxidant effect when exceeding the level.The treated team of 0.06%,0.08%,0.1%have the best color keeping effect of all by analysing corrupt target and color target.According to range analysis of experiment result and the analysis of every target as a whole,the best components of compound antioxidants is A₃B₂C₁D₂,0.1%apple polyphenols+0.02%phytate+ 0.01%niacinamide+0.03%Vc。...