Angiotensin converting enzyme inhibitory peptides in Finnish cereals: a database survey

Angiotensin converting enzyme (ACE) regulates blood pressure (BP) by hydrolytic actions. ACEinhibitors are widely used in the pharmacological treatment of hypertension. Certain food-derived peptides can also inhibit the activity of ACE. This study shows the occurrences of known ACE-inhibitory peptides in cereal storage protein structures. A literature search yielded thirty-nine candidate peptides. Of these, twenty-two peptides were found to occur in the cereal storage proteins. For instance, of the tripeptides (isoleucine-proline-proline or valine-proline-proline) that lower BP in fermented milk products either one appears in cereal prolamins. In addition, oat globulins possess seven of the candidate peptides in their structures, whereas tripeptides leucine-glutamine-proline (LQP) and valine-serine-proline (VSP) occur repeatedly in C-hordeins and ω-secalins (LQP), and D-hordeins (VSP). Cereal storage proteins, thus, appeared as potential sources of ACE-inhibitory peptides. Novel cereal products with BP-lowering effects may be developed by liberation of the target peptides.