Abstract:

Trypsin was used to hydrolyze bovine type Ⅰ collagen with trypsin for the preparation of angiotensin converting
enzyme (ACE) inhibitory peptides. The influence of pretreatment by heating or high-pressure (HP) treatment for a short
time on the degree of hydrolysis (DH) and ACE inhibitory activity of hydrolysates was studied. Heating could improve
hydrolysis of collagen and release of ACE inhibitory peptides. HP pretreatment caused no significant difference in DH from
the untreated control, but exhibited significantly lower ACE inhibitory activity than the control. The correlation between DH
and ACE inhibition implied that ACE inhibition rose rapidly as DH increased, until reaching a plateau at a DH level of 5%.
The peptide profile showed that collagen could be hydrolyzed effectively after heating and the sites hydrolyzed by trypsin
could be changed after HP pretreatment. Sequence analysis of peptides from collagen with heating pretreatment showed
that all sequences were from the triple-helix of collagen and most of them could have strong ACE inhibitory activity, which
implied the triple-helix of collagen could be damaged and ACE inhibitory peptides could be released effectively after shorttime
heating pretreatment.

Key words: trypsin, collagen, pretreatment, hydrolysis, ACE inhibitory activity