Extraction, purification and application of hydrolysed collagen from fish skin

The removal of non-collagen agents usually employs sodium hydroxide. Depending on the chemical composition of the fish skin, sodium hydroxide concentrations ranges from 0.05 M to 0.1 M, the ratio of fish skin weight to sodium hydroxide solution is 1:10 (w/v) and soaking time is from 6 to 24 hours.