PREPARATION AND CHARACTERIZATION OF ALKALI-SOLUBLE COLLAGEN FROM PIGSKIN SHAVINGS

The leather industry discharges large quantities of solid wastes containing high-value native collagen. In this study, the pigskin shavings, generated from the shaving of pelts which had been dehydrated with anhydrous sodium sulfate after deliming, were pretreated to remove most of salt and fat. Then alkaline treatment method was used to extract collagen from the pigskin shavings. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and circular dichroism (CD) spectra revealed that the alkali-soluble pigskin collagen (ASPC) retained the polypeptide chains and triple helix conformation. The amino acid profiles showed no major deviation from the characteristic collagen composition. Both of the denaturation temperature and the isoelectric point (pl) of ASPC were lower than those of pepsin-solubilized pigskin collagen (PSPC). Scanning electron microscopy showed that ASPC sponges had porous fibrillar network structures, and the pore sizes became larger with the decrease of collagen concentrations and as the pH of the collagen solution approached the pl of ASPC.