Effects of Preheating of Soybean Protein on Interaction between Meat Protein and Soybean Protein

The heat-induced gelling properties of mixtures of chicken ground meat and acid-precipitated soybean protein (APS-protein) preheated under various intensities were investigated, in order to elucidate the interaction between meat protein and soybean protein. The jelly strength, Young's modulus and water-holding capacity of mixtures of ground meat and non-preheated APS-protein showed only low values, while their values for the mixtures of ground meat and preheated APS-protein increased with increase of the preheating time. Although these values rapidly increased at the initial stage in preheating (0-4min), after 4min, the jelly strength increased only at a slow rate, while Young's modulus and water-holding capacity remained almost at a constant level. The amounts of preteins in the separated juices from mixed samples decreased with the increase of preheating time. The amounts of the sulfhydryl groups of APS-protein increased with the preheating time until 4min, but after that time, their values rapidly decreased. The physical properties of mixed samples were related to the sulfhydryl groups of APS-protein at the initial stage in preheating (0-4min), but after 4min, this relation was not observed.