Extraction of crude collagen from Pterygoplichthys pardalis skin and determination of functional properties of its hydrolysates

Collagen has a great demand and fish skin is a safe alternative source of collagen. Pterygoplichthys pardalis is an endemic, freshwater fish with no economic benefit. The study was conducted to extract crude collagen from the skin of P. pardalis using a simple method and identify the functional properties of its hydrolysates. Acid and pepsin soluble collagens were extracted from skin using citric acid (CA) and ethylene diamine tetraacetic acid (EDTA). Selected crude collagens were hydrolysed using pepsin, protease and trypsin enzymes (1:100). Extracted crude collagens and best hydrolysates were selected using 8 and 15% SDS-PAGE. Hydrolysates were analysed for antioxidant, Fe(II) chelating and antibacterial activities. CA treatment showed significantly (P<0.05) higher yield than EDTA treatment. Antioxidant properties, metal chelation and antibacterial activities were not significantly (P>0.05) different. Hydrolysates showed significantly (P<0.05) higher functional properties than crude collagen in both treatments. These results conclude that collagen hydrolysates from P. pardalis have good antioxidant, metal chelating and antibacterial properties.