Oxidative characteristics and gel properties of porcine myofibrillar proteins affected by l ‐lysine and l ‐histidine in a dose‐dependent manner at a low and high salt concentration

Summary This study investigated the effects of l ‐lysine (Lys) and l ‐histidine (His) on the oxidative characteristics and gel properties of porcine myofibrillar proteins (MP). Results showed that Lys and His had a strong ferrous ion‐chelating ability and hydroxyl radical‐scavenging activity. Moreover, Lys and His inhibited the protein carbonyl formation and MP aggregation at 0.2 M and 0.6 M NaCl, respectively, in a dose‐dependent manner. Furthermore, 2 and 4 mg mL −1 Lys and His decreased the oxidation‐induced loss of the tertiary structure of MP accompanied by the lower surface hydrophobicity. The water‐holding capacity and gel strength of MP gels increased with increasing Lys and His concentrations due to more regular and lamellar structures with smaller and homogeneous pores at 0.6 M NaCl and more orderly crosslinking via fibrous filament at 0.2 M NaCl. In summary, Lys and His chelated the ferrous ions and scavenged hydroxyl radicals, decreased the oxidation‐induced physicochemical changes, thus preventing oxidative damage during the formation of a three‐dimensional gel network, which resulted in better gel quality.