Broken Rice as a Potential Functional Ingredient with Inhibitory Activity of Renin and Angiotensin-Converting Enzyme(ACE)

The aim of this work was to evaluate the ability of broken rice, an underutilized industrial by-product, as a potential functional and health promoting ingredient. With this purpose, the ability to inhibit the angiotensin converting enzyme and renin of a rice protein hydrolyzate (RPH) obtained from a high-protein variety of broken rice (var. Nutriar FCAyF) was analyzed (IC 50 = 0.87 and 2.7 mg/mL, respectively). RPH was separated by gel permeation chromatography and in a second purification step by RP-HPLC. The sequence of antihypertensive peptides presented in two RP-HPLC fractions was analyzed. Peptides capable of interacting with the active sites of both enzymes were identified. In this study, we demonstrate that the hydrolysis treatment improves functional and biological properties of rice proteins. Protein preparations obtained from a by-product of rice industry, such as broken rice, are a promising ingredient with potentially good biological properties.