Influence of lard-based diacylglycerol on rheological and physicochemical properties of thermally induced gels of porcine myofibrillar protein at different NaCl concentrations

This study investigated the role of lard-based diacylglycerol (DG) on the rheological and physicochemical properties of pork myofibrillar protein (MP) gels at different NaCl concentrations. Incorporated unpurified diacylglycerol (UDG) or purified diacylglycerol (PDG) and increased NaCl concentration significantly enhanced gel compression force, water-holding capacity, storage modulus values (G′), and loss modulus values (G″) (P < 0.05). Scanning electron microscopy results showed that the incorporation of DG promoted a more compact and uniform three-dimensional gel network filled with protein-coated fat globules. The increase in NaCl concentration and addition of UDG or PDG significantly increased the immobilized water contents and decreased the free water contents (P < 0.05) and also caused the increases in the amount of α-helix and β-sheet concomitant with decreases in β-turn and random coil contents. Overall, the increase in NaCl concentration and the incorporation of DG exhibit an enhancing role on the rheological and physicochemical of porcine MP.