Optimization of extraction process and basic properties for pepsin-soluble collagen from Golden pompano skin

To improve the utilization rate of fish skin in processing by-product of Golden pompano, this paper used the response surface Box-Behnken method to optimize the extraction process of pepsin-soluble collagen ( PSC) from the skin of Golden pompano.Based on the previous single factor experiment, the model was established by three factors ( enzyme concentration, liquid-to-solid ratio and extraction time) .In addition, the basic properties of PSC were characterized and compared with acidsoluble collagen ( ASC) by Sodium Dodecyl Sulfate Poly Acrylamide Gel Electrophoresis ( SDS-PAGE) , Attenuated Total Reflectance Fourier Transform Infrared spectroscopy ( ATR-FTIR) and Differential Scanning Calorimeter ( DSC) . The results showed that the optimum extraction conditions were 1.5% enzyme concentration, 23∶ 1 m L/g liquid-to-solid ratio, and 27.5 h extraction time.Under this condition, the actual yield of collagen of Golden pompano skin was 64.68%, which was close to the predicted value ( 65.17%) .Moreover, the PSC obtained in this experiment had higher denaturation temperature ( 30.44 ℃) and preliminarily identified as type I collagen, which was similar to the electrophoretic and infrared peaks of ASC. The technical reference for the extraction of PSC from Golden pompano skin was given in this research.