Effect of different process parameters on the rheological properties of ginger protease-induced milk gels

Ginger protease with milk coagulating activity was isolated from ginger root. The rheological properties of ginger protease inducing skim milk gels were investigated. Also the processing conditions at a dynamic heating pattern for making skim milk gel and its physicochemical variation during cold storage were assayed.The results showed that storage modulus of ginger protease inducing skim milk gel were high at temperatures over 60℃. The rate of increase in storage modulus of skim milk gel made at a heating rate of 1℃ /min from45℃ to 80℃ was the highest. During the cooling process, storage modulus of milk gel increased significantly, and there was a peak value at 45℃ for loss tangent value and tended to be constant below 20℃. The storage modulus, loss modulus, and loss tangent of milk gel gradually decreased during cold storage, and stabilized after 2h storage. These results showed that dynamic heating pattern enabled the ginger protease to form skim milk gel with high gel strength and cold storage stabilized the milk gel.