l-Arginine/l-Lysine Alleviated the Deterioration of Emulsion Sausages with Partial Replacement of Porcine Backfat by Soybean Oil by Hindering Hydroxyl Radical Stressed Oxidation of Meat Proteins

Myosin oxidation destroys its gelling and emulsifying properties, which decreases the yield and deteriorates the mouthfeel and chewiness of meat products. This work investigated the effects of l-arginine (Arg)/l-lysine (Lys) on the physicochemical properties of emulsion sausages prepared from pork batter oxidatively stressed by hydroxyl radicals (•OH). Four sausage samples with partial replacement of porcine backfat by soybean oil (control and sample treated with •OH, a combination of •OH and Arg, or a combination of •OH and Lys, respectively) were prepared, and their physicochemical properties were determined. Under •OH stress, the addition of Arg/Lys increased L*, a*, hardness, springiness, cohesiveness, and chewiness (P < 0.05) but decreased the cooking loss, total expressible fluid, and expressible fat/oil (P < 0.05). Furthermore, both Arg and Lys decreased the carbonyl content (P < 0.05); meanwhile, Lys increased the total sulfhydryl content (P < 0.05). Confocal laser scanning microscopy indicated that Arg and Lys caused the formation of more regular and uniform oil droplets embedded in a protein gel matrix. The results disclosed that Arg/Lys could retard meat proteins from oxidation under •OH stress, which is favorable for meat proteins to keep their functional properties, ultimately reducing the quality deterioration of meat products.