Abstract: In order to clarify the relationships between the antioxidant activity in vitro of different antioxidants permitted to be added in heat-processed meat products according to the national standard of China GB 2760-2014 and their inhibitory effect on protein and fat oxidation, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing power of eight selected antioxidants were determined, and the effect of separately adding the antioxidants to heat-processed meat products was investigated on protein and lipid oxidation as reflected by thiobarbituric acid reactive substance (TBARS) value as well as the contents of carbonyl and sulfhydryl groups. The results showed that the total polyphenol content, DPPH radical scavenging capacity and reducing power of rosmarinci acid (RA), tea polyphenol (TP), theaflavins (TF) and carnosic acid (CA) were all significantly higher than those of glycyrrhiza extract (GE), extract of bamboo leaves (BL), sodium phytate (SP) and potassium sorbate (PS). For roasted and fried meat patties, there were large differences in the inhibitory effect of different antioxidants against protein and fat oxidation. BL was the most effective antioxidant suitable for all six processed meat products, TF was more suitable for roasted chicken patties and beef patties, TP was more suitable for roasted beef patties and pork patties, SP was more suitable for fried chicken patties and beef patties, and CA was more suitable for fried beef patties and pork patties. Overall, the antioxidants with strong antioxidant activity in vitro (RA, TP, TF, and CA) may not necessarily strongly inhibit protein and fat oxidation in heat-processed meat products, while the antioxidants with weak antioxidant activity in vitro can have strong inhibitory activity (BL and SP). This implies that there may not be a significant correlation between the antioxidant activity in vitro of different antioxidants and their ability to improve the oxidative stability of heat-processed meat products.

Key words: antioxidants; antioxidant activity in vitro; heat-processed meat products; fat oxidation; protein oxidation