Abstract: In order to elucidate the thermal denaturation mechanism of pepsin-solubilized collagen (PSC), intact PSC was extracted from jellyfish umbrella. The denaturation temperature of PSC under different heating rates, and the rates of residual PSC after heating at different temperatures for different times were investigated by a microcalorimeter. The thermal denaturation kinetics of PSC was analyzed as well. The results showed that the endothermic peak gradually moved towards lower temperature area with the decrease in heating rate, suggesting that the denaturation temperature of PSC declined with the decrease in heating rate. However, the change in heating rate did not show any significant impact on the heat of reaction. As the temperature rose, the increase of energy per unit time, namely the quantity of heat, could increase the degeneration rate of PSC, thereby shortening the degeneration time of PSC. The thermal denaturation process of PSC could be described by a regression equation with a reaction order of 0.9. At 34, 35, 36, 37, 38 and 39 ℃, the D90 values (time required for 90% denaturation) were 53.76, 26.11, 15.75, 4.89, 4.26 and 2.55 min, respectively. The Z90 value (temperature change for 90% reduction of D value) was 3.69 ℃. The apparent activation energy was 481.90 kJ/mol. This research can provide a theoretical guideline for further development and utilization of jellyfish collagen.

Key words: jellyfish, pepsin-solubilized collagen, thermal denaturation, kinetics