Study on the production technology of Qula rennet casein

The productive technology of rennet casein was optimized and verified by pilot test. The orthogonal was designed to optimized process parameters by four factors on effecting Qula dissolution rate, four color fixative on improving rennet casein color and three factors on effecting the centrifuge and degrease of Qula solution. The result showed that the optimum technological parameter of Qula dissolution rate was pH10.5, temperature 55℃, stir speed 300r/min and material concentration 10%. The optimum technological parameters of four color fixative matching were Na 2 S 2 O 4 0.2% , NaHSO 3 0.2% , EDTA 0.05% and Na 2 S 2 O 5 0.23% . The optimum technological parameters of centrifuge and degrease were gravity disc inner diameter 108mm, feedstock flow 2.5t/h, slagging interval time 5min. The 15 batch products were made sensory evaluation and chemical & physical test. The sensory evaluation result showed that the product was yellowish powder, odorless and tasteless. The average value of chemical & physical test result showed that protein 91.0% , fat 0.6%, lactose 0.19%, moisture 10.3%, ash 5.0% and pH7.07. The quality of products was improved greatly after optimizing. Qula dissolved rate increased by 20.7% , rennet casein sensory indexes improved significantly, fat content dropped 50%, and other physical and chemical indexes were better.