Parameters affecting the isolation of collagen from squid (Illex argentinus) skins

The solubility of collagen from squid (Illex argentinus) skin in salt solut ions and the efficiency of removal of skin chromatophores were determined. Homogenization of minced squid skin in 5-15% NaCl solution at 0 degrees C s olubilized 35-24% of total amount of crude protein and caused 2-5% loss of collagen but was not effective in removing pigments from the skin. The trea tment of whole squid skins in 5-15% NaCl solutions at room temperature led to separation of the chromatophores, but the loss of soluble collagen was 5 7-16%. Collagen, soluble in dilute acid solutions was isolated from squid s kins by 24 h soaking in 10% NaCl solution at room temperature, washing with water and bleaching for 48 h in 1% H2O2 in 0.01 M NaOH. The yield of colla gen was 53%. It could be increased to 90% by using NaOH solution at pH 11.5 instead of 10% NaCl but the isolate was less soluble in dilute acid and th e viscosity of 0.5% dispersion of collagen was four times lower. The rancid off-odour could be prevented by adding 0.5% of a nonionic detergent to all solution used in the procedure. (C) 1999 Elsevier Science Ltd. All rights reserved.