Study On The Technology Of Quality And Safety Control Of Chilled Meat

In order to study preservation effect of natural compound preservative which arecomposed of chitosan，lysozyme and ascorbic acid in this article, the sensory，physical and chemical properties (including water-holding capacity, proteindegradation, lipid oxidation) and microbial indicators of chilled meat wereinvestigated． The results of the study are described as follows：In order to analyze and compare preservation effect of the natural compoundpreservative randomly composed by chitosan， lysozyme and ascorbic acid to sensoryof chilled meat, single factor experiment was applied．The result showed that thepreservation effect of the compound preservative composed of these three naturalpreservatives was far better than that of the single preservative．In order to evaluate natural compound preservatives effect of differentconcentration ratio on chilled meat, orthogonal experiment L9（34） was applied andthe sensory quality, physical and chemical indicators, such as drip loss rate, pH values,TVB-N values, POV values, TBA values, acid values were investigated．The resultsof the experiment showed that, during chilled meat stored at0-4℃for12days, thenatural compound preservative can effectively suppress the drip loss, inhibit pH valueand can effectively prevent TVB-N content and lipid peroxidation of chilled meat,reduce the increase of the value of TBA, acid and POV, but the preservation effect ofdifferent concentration ratio of natural compound preservatives to chilled meat isdifferent, Group4natural compound preservative of2.0%chitosan,0.15%lysozyme,0.04%ascorbic acid had the best preservation effect on the chilled meat．As we cansee, all the physical and chemical quality indicators were below the national standardof Group4at the9th day of storage. The value of TVB-N was13.19mg/100g,whereas national standard of15mg/100g. At the12th day of storage it was15.99mg/100g, slightly more than the national standard. TVB-N value of the blankcontrol group at6th day of storage was16.66mg/100g．Other physical and chemicalindicators of Group4were lower than other groups on the same day of the measuredvalues．Sensory quality of the chilled meat of Group4was also better than the othertest groups．Through the range analysis of the orthogonal experiment data， the result can beseen: lysozyme has the largest influence on maintaining the physical and chemicalproperties of the chilled meat， followed by chitosan， ascorbic acid has the minimalimpact． The optimal level combination to maintain the physical and chemicalproperties of chilled meat was A2B1C3,2.0%chitosan,0.15%lysozyme,0.04% ascorbic acid, matched with the measured values of Group4in the orthogonalexperiment．Compared inhibition of microbial growth in chilled meat stored at0-4℃ofGroup4with the blank control group, the total bacterial counts，Enterobacter counts，Pseudomonadaceae counts and Lactobacillus counts were investigated. The resultsshowed that after the application of natural compound preservative of Group4,microbiological indicators were lower than the blank control group, in which afterapplication of compound preservative the total bacterial counts at the10th day wasslightly over the national standard of106cfu/mL, while the blank control group at the5th day has been over the106cfu/mL．To sum up，the ratio of the Group4(2.0%chitosan,0.15%lysozyme and0.04%ascorbic acid) has good preservation effect on the sensory evaluation, physical andchemical indicators, microbiological indicators, which can extend shelf-life of chilledmeat to the9th day，increase the shelf-life by4-5days than the blank control group．...