Angiotensin-I-converting enzyme (ACE)-inhibitory and antihypertensive properties of squid skin gelatin hydrolysates

► Gelatin extracted from squid skin was hydrolysed with pepsin to prepare ACE inhibitory peptide. ► Ultrafiltration was used to separate hydrolysate of squid skin gelatin. ► The fraction HSSG-III (MW < 2 kDa) showed the most potent ACE inhibitory activity. ► The HSSG-III remarkably reduced the arterial blood pressure.