Effect Of Compound Preservative On Storage And Quality Of Chilled Mutton

In the process of storage,and transportation and sales,by the extension of time,the flavor and nutritional value of chilled mutton were severely lost.To increase the quality of chilled mutton and prolong the shelf life,this study used Ascorbic acid,Nisin,and Tea polyphenols three preservatives as the main component to developed compound preservative.The optimal formula of compound preservative was obtained by single factor and response surface optimization test,then the compound preservative was applied to chilled mutton,and the fresh-keeping effect of compound preservative was studied.The main results are as follows:Taking the total number of colonies,volatile base nitrogen value and p H value as evaluation indexes,the dosage of three preservatives with good fresh-keeping effect was obtained by single factor test and the response surface optimization test with three factors and three levels was carried out.Taking the reciprocal of volatile base nitrogen(1/TVB-N)as the response value,the optimal formula of compound preservative was determined as follows: 0.25% of Ascorbic acid,0.06% of Nisin,and 0.20% of Tea polyphenol.The effects of compound preservative on the microbial,sensory and physicochemical indexes of chilled mutton showed that compound preservative had significant inhibition on the microbial indexes(total number of bacteria,enterobacter,lactic acid bacteria and pseudomonas)of chilled mutton(P<0.05),and the antibacterial effect of vacuum preservative group was the most obvious.In terms of sensory evaluation,the sensory scores of the control group decreased sharply during the period of 4-7 days,and the sensory indexes continued to deteriorate and the sensory traits were unacceptable at the10 th day.The vacuum preservative group could maintain the better sensory index of chilled mutton until day 13.In terms of physical and chemical indicators,in the middle and late storage period,p H value and volatile base nitrogen value of vacuum preservative group were significantly lower than those of other groups(P<0.05).Compared with other treatment groups,the shear force of L*,a * and b * values in color of vacuum preservative group had the smallest change range,which could better maintain the original muscle tissue state of mutton and had the best stability of meat color.The analysis results of volatile flavor substances in chilled mutton during storage showed that there were no adverse flavor substances in chilled mutton treated with compound preservative.The types of alcohols in the flavor substances decreased significantly,but most of them did not have characteristic aroma,and had no significant effect on the overall flavor of chilled mutton.The newly added flavor substances,such as heptanal,benzaldehyde,decanal,acetophenone,tridecane and lauryl alcohol,improved the flavor of chilled mutton slightly.Through the comprehensive evaluation of microbial,sensory,physical and chemical indexes of chilled mutton,the storage period of the control group was 6 days,while that of the vacuum preservative group,the preservative group and the vacuum group were 15,11 and 9 days,respectively,which were 9,5 and 3 days longer than the control group.