Obtaining of peptides with in vitro antioxidant and angiotensin I converting enzyme inhibitory activities from cañihua protein (Chenopodium pallidicaule Aellen)

Hydrolysates and peptides from a cañihua protein concentrate with antioxidant and angiotensine-I converting enzyme (ACE) inhibitory activities were evaluated in vitro. Hydrolysates were obtained via enzymatic hydrolysis using: Alcalase, Neutrase and Flavourzyme, in reaction in one and two sequential stages. The protein hydrolysate obtained in two sequential stages (Neutrase-Alcalase for 180 min at 50 °C), presented the highest antioxidant activity and ACE inhibition (2.12 μmol TE/mg and 69.8%, respectively) and a low IC50 value (0.12 mg/mL). This hydrolysate was further purified through ultrafiltration with membranes of cut off values of 10 and 3 kDa, followed by size exclusion chromatography and a total of three fractions were obtained (F-I, F-II and F-III, respectively). LC-MS/MS analysis revealed peptides composed of 3-11 aminoacids in F-II and F-III which were identified via cross species identification within the polypeptidic chain of protein 11S seed globulin of Chenopodium quinoa. F-III outstood in the evaluated bioactive properties (3.18 μmol TE/mg, 78.4% and 55 μg/mL). Up to our knowledge, this is the first study focused on obtaining of protein hydrolysates and peptides with bioactive properties from cañihua. These results could be used to obtain products from cañihua with added value as potential functional ingredients.