Abstract:

A certain amount of salts were introduced into fish antihypertensive peptides during the process of fish protein hydrolysis and 10% of ash in the final products was capable of influencing its activities and quality. The desalting technology of fish antihypertensive peptides by DA201-C macroporous adsorption resin was investigated as well as its physic-chemical properties after desalting. The results indicated that the optimum condition for desalting was obtained as follows: loading sample concentration of 10 mg/ml, sampling flow rate of 1.5 BV/h and 70% alcohol as eluent. Under this condition, the ash content in fish antihypertensive peptides was decreased from 13.89% to 3.89%, and its ACE inhibitory activity increased from 64.35% to 95.00%. Molecular weight of fish antihypertensive peptides distributed from 200 to 7000D, and the content of peptides from 200 to 2000D accounted for 81.7% of total peptides. The solubility at pH 2 － 12 was over 98% and its moistureabsorption was similar with soybean peptides while the rate of absorption moisture was lower than urea and higher than glycerol.

Key words: fish antihypertensive peptides, macroporous adsorption resin, ACE inhibitory activity, desalting, physico-chemical properties