Study On Intramuscular Lipid Oxidation And Influencing Factors In Chicken After Heat Treatment

At present,chicken meat is the second largest meat consumer product in China,with high edible value and nutritional value.The processing and storage of chicken products must be accompanied by oxidation of meat.The degree of lipid oxidation is an important parameter to measure the quality of meat,and temperature is an important process parameter affecting lipid oxidation.The mechanism of muscle lipid oxidation is very complicated.In this paper,chicken breast meat is the main research object,and the regulation of muscle lipid oxidation during heating and cold' storage is explored.The relationship between endogenous pro-oxidation and anti-oxidation factor and lipid oxidation in muscle is clarified.The proteomics method was used to further verify the effect of pro-oxidation or anti-oxidation proteins on lipid oxidation during heating,in order to understand the mechanism of endogenous pro-oxidation and anti-oxidation factors on lipid oxidation during heat treatment.The main findings are as follows:1.The heating temperature and refrigerating time were used as experimental factors to determine the changes of muscle fatty acid composition and TBA value.The effects of temperature and storage on lipid oxidation were studied.The results showed that the relative content of unsaturated fatty acids decreased significantly during the heating process,while the content of saturated fatty acids increased(P<0.05).The FFA content did not change significantly with the refrigerating time(P>0.05).The TBA value increased significantly with increasing temperature and prolonged refrigerating time(P<0.05).It is indicated that heating promotes oxidation of muscle lipids.2.Determination of the activities of endogenous antioxidant enzymes(CAT,SOD,GSH-Px),hydroxyl radicals(·OH)and metal ions(Fe,Cu)in chicken meat,and studied the promotion of oxidation and antioxidant factors to lipids.The mechanism of mass oxidation.The results showed that the total iron,Cu and·OH content increased with the increase of temperature,while the heme iron and antioxidant enzyme activities decreased with the increase of temperature(P<0.05).Among them,the·OH content increased sharply at 60 0C,while the heme iron and GSH-Px activity decreased at the temperature of 60?,and the SOD and CAT decreased significantly at 60? and 70?,respectively.And TBA value and free radicals,metal ions(Total Fe,Cu)were positively correlated with the increase of temperature,and negatively correlated with antioxidant enzymes.The results showed that the oxidative stability of chicken meat was synergistically affected by endoge-nous pro-oxidation and anti-oxidation factors.3.The proteomics method based on LC-MS further validates the correlation between pro-oxidation or anti-oxidation protein changes and lipid oxidation.Four types of differential proteins associated with lipid oxidation were identified:structural proteins(35.90%),antioxidant enzyme proteins(10.26%),redox proteins(10.26%),and metal ion binding proteins(43.59%).The antioxidant protein content of SOD and GSH-Px began to decrease at 60?,while CAT began to decrease at 70?.The iron binding protein content begins to decrease at 60?-70?.TBA values were inversely correlated with antioxidant protein content as a function of temperature.The results verified that the pro-oxidation and anti-oxidation proteins in the heating process jointly regulate the oxidation of muscle lipids.