2.12. Differential scanning calorimetry (DSC) of carp skin collagens DSC measurement was carried out using the DSC 8000 Series Advanced Double-Furnace DSC (Perkin-Elmer, Waltham, MA, USA) following the method of Liu et al. (2014). The maximum transition tem- perature (Tmax, °C) of the ASC and PSC from the skin was defined as` the temperature of the endothermic peak. The Tmax and enthalpy (AH, J/g) change were assessed from the peak of the DSC thermogram.