Changes In Meat Quality And Effect Of Antioxidants On Color Stability Of Beef During The Postmortem Cold Storage

Consumers pay more and more attention to meat quality of beef, and the beef color of quality directly decided to purchase desire of consumers. Antioxidants can improve the color stability. The experiment with Western qin hybrid cattle supraspinatus(SU), longissimus dorsi(LL) semimembranosus(SM) as raw materials, and they were stored at 4℃ in aerobic environment. Determining quality(shearing force, water loss rate, cooking loss), color(L*, a*, b* value), oxymyoglobin(OxyMb) content, metmyoglobin(Met Mb) content, and endogenous antioxidant capacity(total phenol content, radical scavenging ability(RSA), tocopherol equivalent antioxidant capacity(TEAC)) of muscles in the storage of the 1, 3, 5, 7, 9 days. Using the dynamic data analysis and correlation analysis to explore the beef quality change rule, color stability mechanism and the endogenous antioxidants capacity impact on color stability. Exploring exogenous antioxidants for color stability impacts by adding natural antioxidant(tea polyphenols, Vc, Ve), and determining the optimal formula of compound antioxidants by using the response surface. The study could be used to give theoretical guidance on improving the beef quality and color. The results are as follows:1. Shearing force, water loss rate and cooking loss of SU, LL, SM increase with the extension of storage time, and then drop after reaching the maximum on the third day of storage. The three parts of shear force, water loss rate, cooking loss are differences. Beef began to mature after storage of the third day. The fit of linear model of shear force and water loss rate are very low. Cooking loss of the beef with the extension of storage time is not linear.2. L* values of SU, LL, SM first increase then decrease with the extension of storage time. a* value of SU, LL, SM significantly decrease with the extension of storage time(p<0.05). b* values of SU, LL, SM increased slowly with the extension of storage time. Three parts of the L* and b* values are basically identical, and a* value differences.Beef color has browned during aerobic storage. The fit of the linear model of a* and b* value are good. L* values’ changes of the three parts of the beef with the extension of storage time is not linear.3. OxyMb% of SU, LL, SM significantly declines as the extension of storage time(p<0.01). OxyMb% of SU, LL, SM significantly increases as the extension of storage time(p<0.01). Oxy Mb% are differences in the three parts of the beef and the difference is irregular. MetMb% of LL is the least. The fit of the linear model of Oxy Mb and Met Mb are good.4. Total phenol content, RSA, TEAC of SU, LL, SM decrease with the extension of storage time, and the three parts of them are basically no difference. Muscle endogenous antioxidant capacity decreases gradually during storage. The fit of the linear model of total phenol content, RSA and TEAC are good.5. a* and b* value of SU, LL, SM is linear positive correlation with Oxy Mb% and negative correlation with MetMb%. L* value of the three parts of the beef are no correlation with OxyMb% and MetMb%. Oxy Mb% and Met Mb% of muscle significantly affect a* value(p<0.01) and b* value(p<0.05). Beef color has browned because of the generation of MetMb.6. Total phenol content, RSA, TEAC of SU, LL, SM are linear positive correlation with OxyMb% and negative correlation with Met Mb%. Muscle endogenous antioxidant capacity has a significant influence on color stability(p<0.05).7. Adding natural antioxidants can inhibit MetMb% of the Beef, and the inhibition is tea polyphenols > Vc > Ve. Using Box-Behnken design model to determine the best ratio of compound antioxidants is tea polyphenols content is 0.09%, Vc content is 0.13%, Ve content is 0.15%, and the Met Mb% can be reduced to 27.45%.