Study On Lipid Oxidation And Anti-Oxidation Of Dry Cured Meat Products During Processing

Dry-cured meat products are the classic representative of Chinese traditional meat products with long development history, whose special flavor is loved by consumers. However, serious lipid oxidation has been the key factor limiting Chinese traditional cured meat products development for laggard and rough processing technology. The aim of this research is to investigate changes of lipid oxidation of Chinese bacon and dry cured ham during processing, analyze the effect of anti-oxidation treats on the inhibition of lipid oxidative changes by using natural antioxidants combined with edible films in order to provide a theory base for the problem of lipid peroxidatio in dry cured meat products production.By experiment design, the researches comprise three parts:1、Study on changes of lipid oxidation and anti-oxidation technology during Chinese bacon processing:The chapter was aimed at analyzing the changes of lipid oxidation during Chinese bacon processing and studying the effect of anti-oxidation treats on the inhibition of lipid oxidative changes by adding the rosemary extract, grape seed extract(GSE) and GSE combined with lard at pre-fermentation period. The results showed that acid value and TBARs value of surface lipid had been increasing, significantly positively correlated with processing temperature(r=0.95,0.90; p<0.05), peroxide value had overall upward trend with increasing and falling. The lipid oxidation values of Chinese bacon added rosemary extract, GSE and GSE combined with lard treats were much lower than the control group:Acid value seperately reduced by 13%,32% and 41%, peroxide value seperately reduced by 20%, 31% and 40%; TBARs values reduced by 14%,27% and 35% at ripening end. This indicated that the anti-oxidation effects of GSE and GSE combined with lard treats were more effective than the treatment added rosemary extract.2、Study on changes of lipids oxidation and anti-oxidation technology during ferment aging processing of dry-cured ham:The chapter was aimed at researching the inhibition of lipid oxidation changes of dry-cured ham treated by GSE and GSE combined with lard during ferment-aging processing. The results showed that peroxide value, TBARs value of dry-cured ham treated by adding GSE was significantly lower than the control group during ferment-aging processing(P<0.05). At ripening end, peroxide value, TBARs value, carbonyl value and diene value in semimembranosus muscles significantly reduced by 57%,48%, 29%,18%, surface fat decreased by 60%,24%,42%,36%, compared to the control group; While the lipid oxidation value of the treat of GSE combined with lard had no significant difference with the control group (P>0.05). The results indicated that the anti-oxidation effect of GSE was better than GSE combined with lard treat.3、Effect of the combination treat of antioxidants and edible films on lipid oxidation of dry-cured ham:The chapter was aimed at studying effect of four factors:time of anti-oxidation treat, antioxidant, edible film and coating thickness of films on the lipid oxidation of dry-cured ham through the L9(34) orthogonal test. The results showed that the anti-oxidation treat in the ferment metaphase was better than the end of fermentation and mid-maturing; natural antioxidants(GSE, compound antioxidants of rosemary and VE) had the same anti-oxidation effect with synthetic antioxidant(BHT); carboxymethyl cellulose film inhibited lipids oxidation best, whose acid value, peroxide value and TBARs value in the semimembranosus muscles respectively reduced by 13%,27% and 10% compared with the treat without coating film(P>0.05). The optimizing result of orthogonal test was that dry-cured ham was sprayed natural compound antioxidants of 0.05%rosemary and 0.05%VE, then applied three layers carboxymethyl cellulose film on the surface of the dry-cured ham during the mid-fermention period. It was well consistent with the sensory evaluation results.