• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.3
• /
• pp.176-181
• /
• 2008

To evaluate the effective use of endoprotease from squid viscera as a food processing aid, various methods of fractionating endoprotease from viscera of the Argentina shortfin squid (Illex argentinus) were evaluated. The endoprotease-positive fractions of each fractionation were fraction II (30-40%, w/w) with cold acetone, fraction IV (50-60% saturation) with ammonium sulfate, fraction UF with anion exchange chromatography, and fraction II (15-24 kDa) with gel filtration. The specific activities (approximately 25 U/mg) of the fractions using ammonium sulfate and gel filtration were higher than the others. Total azocaseinolytic activity and recovery of the positive fraction using gel filtration were 806.95U and 37.82%, respectively, and were the highest among the positive fractions. Based on the results, gel filtration was the most efficient method for fractionating endoprotease from the viscera of Illex argentinus.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.2
• /
• pp.135-143
• /
• 2014

Exopeptidase active fractions from the hepatopancreas of the Argentina shortfin squid Illex argentinus, were obtained with acetone (AC 30-40%), ammonium sulfate (AS 60-70% saturation), anion exchange chromatography (AE-II, 0.2 M NaCl) and gel filtration chromatography (GF-I, 30-50 kDa) fractionation methods. A bitter peptide solution that has a bitterness equivalent to that of 2% glycylphenylalanine and prepared by tryptic hydrolysis of milk casein, was treated with the exopeptidase active fractions. The GF-I fraction was the best based on aminopeptidase activity (35.3 U/mg), percentage of recovery (30.7%) and a sensory evaluation (1.7). The amount of released amino acids increased as incubation time increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides as revealed by the reverse-phase high performance liguid chromatography profile, with three peaks (3, 5 and 6) decreasing in area (%) and three peaks (1, 2 and 4) increasing in area (%). Therefore, the GF-I fraction appeared to be ideally suited to reduce bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.8
• /
• pp.1009-1017
• /
• 2008

For the effective use of exopeptidase from squid viscera as food processing aids, the viscera of Argentina shortfin squid (Illex argentinus) were fractionated by various methods such as acetone treatment, ammonium sulfate treatment, anion exchange chromatography, and gel filtration. The positive exopeptidase fractions were obtained from the fraction II treated by cold acetone ($30{\sim}40%$, w/w), the fraction V by ammonium sulfate ($60{\sim}70%$ saturation), the fraction II (0.2 M NaCl) by anion exchange chromatography, and the fraction I ($30{\sim}50\;kDa$) by gel filtration. The specific activities of positive fractions from viscera of I llex argentinus against substrates were higher to LeuPNA than to ArgPNA. Total activity and recovery against LeuPNA of positive fraction by gel filtration were 1,867 U and 30.69%, respectively, which were the highest among those of positive fraction. The results suggested that the gel filtration chromatography method was the most efficient method for the fractionation of exopeptidase from viscera of Illex argentinus.