Production of Protein Hydrolysates Teff (Eragrostis tef) Flour with Antioxidant and Angiotensin-I-Converting Enzyme (ACE-I) Inhibitory Activity Using Pepsin and Cynara cardunculus L. Extract

Abstract

In recent years, several studies have shown the antioxidant and antihypertensive potential of bioactive peptides. Thus, bioactive peptides are likely to be a valuable substance for the development of functional foods. There are a wide variety of sources of these peptides, including several cereals. Teff is an Ethiopian-rooted cereal with an interesting nutritional profile, mainly due to its high amount of protein. In this study, teff flour was subjected to a defatting process for optimizing the protein extraction. Such extraction was performed by precipitation from its isoelectric point, a crucial step that separates the protein from other components based on their charge. The protein obtained was subjected to enzymatic hydrolysis by pepsin and Cynara cardunculus L. The antihypertensive (angiotensin-I-converting enzyme ―ACE-I― inhibitory activity) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl ―DPPH― radical scavenging activity) of the peptides were determined. According to the IC50 values, the results obtained showed that the peptides from teff flour show promising bioactivity compared to other cereals. Furthermore, the peptides from teff flour obtained from C. cardunculus L. showed higher antioxidant activity (defatted teff flour ―DTF―: 0.59 ± 0.05; protein extract ―EP― : 1.04 ± 0.11) than those obtained with pepsin (DTF: 0.87 ± 0.09; EP: 1.73 ± 0.11). However, C. cardunculus L. hydrolyzate peptides showed lower inhibitory activity of ACE-I (DTF: 0.59 ± 0.07; EP: 0.61 ± 0.05) than the pepsin hydrolyzate (DTF: 0.15 ± 0.02; EP: 0.33 ± 0.05).