Abstract: The water soluble total protein (TP) of selenium-enriched Spirulina platensis (SeSP), named as SeSP-TP, was extracted by phosphate buffer and then hydrolyzed by 5 different proteases to produce SeSP peptides (SeSP-Ps). The angiotensin convert enzyme (ACE) inhibition of SeSP-Ps was measured in vitro. The results showed that treatments with different proteases caused obvious difference of hydrolysis degree (HD) to SeSP-TP, and the combined use of pepsin, trypsin and chimotrypsin led to the highest H. Furthermore, we found that all SeSP-Ps produced by various proteases could inhibit ACE. The 50% ACE inhibition concentration (IC50) of SeSP-Ps derived from the combination of pepsin, trypsin and chimotrypsin was 74.6μg/mL, which was the lowest in comparison with SeSP-Ps obtained with each of the three enzymes or papain. The present results implied that the excellent functional food SeSP contains highly active dose-dependent ACE inhibition peptides.

Key words: angiotensin convert enzyme, Spirulina platensis, selenium, peptide