Abstract

It was reported that supercritical fluids could increase the reaction rates and stability of enzymes. The transglutaminase (TGase) was used as a cross-linking agent for collagen fibre and cattle hide in supercritical carbon dioxide (SCF-CO2) medium. The denaturation temperature (Td) and shrinkage temperature (Ts) of the cross-linked samples were determined. SCF-CO2 could improve the crosslinking reaction of the TGase with the collagen fibre and cattle hide according to the denaturation temperature determination. For collagen fibre, the Td of TG-SCF-Collagen is about 20°C higher than that of TG-Collagen in water medium. While the Td of cattle hide treated with TGase in SCF-CO2 is about 10°C higher than that of in water medium. Interestingly, the shrinkage temperature of the cattle hide did not show any change while it was treated by TGase both in SCF-CO2 medium and in water. However, the appearance of the hide after TGase treatment was tighter and finer with the area reduction. The results implied that intermolecular cross-linking created by TGase did not like the crosslinking by chrome (III) tanning agents, which formed rigid structures among the collagen fibrils that play the main role for the increase of shrinkage temperature of leather.