Amino acid composition and antioxidant activities of hydrolysates and peptide fractions from porcine collagen.

摘要

Amino acid composition and antioxidant activities of different hydrolysates from porcine collagen were analysed. Gelatin was hydrolysed with various proteinases, namely papain, proteinase from bovine pancreas, proteinase from Streptomyces, and a cocktail mixture of proteinase from bovine pancreas and proteinase from Streptomyces. The hydrolysates were analysed for DPPH radical-scavenging ability, metal-chelating ability and lipid peroxidation inhibitory activity. It was found that collagen hydrolysates obtained via different proteinase treatments had different amino acid compositions and antioxidant properties. However, contents of Hyp and Pro were improved and content of Gly was decreased in each collagen hydrolysate compared with collagen. The hydrolysate prepared with the cocktail mixture of proteinases, which exhibited the highest antioxidant activity, was separated into 6 fractions by gel filtration chromatography. Fraction 2 was further separated by ion exchange chromatography. Fraction 2b with abundant basic amino acids and Fraction 2d, which was slightly acidic, demonstrated highest radical-scavenging and metal-chelating activities, and both Fraction 2b and 2d contained relatively high levels of hydrophobic amino acids. The antioxidative peptides were rich in Hyp, Pro and Gly, which accounted for half of their amino acid composition.