Abstract: To get the structure and function information about ACEI(angiotensin coverting enzyme) inhibitors derived from food protein. The present study prepared ACEI inhibitors from rice bran. The method of isoelectric point (PI) precipitation was adopted to obtain rice bran protein, which was hydrolyzed by pepsin, trypsin, and papain individually or jointly. The hydrolyzed products were separated according to the differences of molecular weights by Sephadex G-15 gel chromatogram. The components with the highest ACE inhibitor activity measured by FAPGG methods, were separated further by SP-Sephadex C- 25. HPLC-MS analysis showed that the highest inhibiting activity comes from pepsin-trypsin digested components, which containing short peptides such as Arg-Tyr, Met-Trp, Gly-Val-Tyr or Gly-Asp-Phe with the common characteristics of phenyl ring-like structure which maybe the important structural charecteristics.

Key words: rice bran protein, ACE, Inhibitors, IC50, HPLC-MS ..