Obtenção de hidrolisados enzimáticos do concentrado protéico do soro de leite com alto teor de oligopeptídeos e elevada atividade inibitória sobre a enzima conservadora de angiotensina, utilizando a pancreatina e a papaína

Abstract

PREPARATION OF ENZYMATIC HYDROLYSATES WITH HIGH OLIGOPEPTIDE CONTENT AND ANGIOTENSIN-CONVERTING ENZYME INHIBITORY ACTIVITY FROM WHEY PROTEIN CONCENTRATE USING PANCREATIN AND PAPAIN.Protein hydrolysates have been used in clinical practice in the manufacture of special foods for individuals with special physiological and nutritional needs. Thus, the aim of the present study was to obtain enzymatic hydrolysates from whey protein concentrate (WPC) with high oligopeptide content and inhibitory activity (IA) of the ngiotensinconvertingenzyme (ACE). Some parameters were evaluated such as type of enzyme(pancreatin and papain), enzyme:substrate ratio (E:S = 0.5:100, 1:100, 2:100 and 3:100), and the use of ultrafiltration. First, the peptide profiles of the hydrolysates were characterized using fractioning by yze-exclusion-HPLC followed by a rapid Corrected Fraction Area method for the quantification of the peptide and free amino acid contents. Several hydrolysates showed nutritionally appropriate peptide profiles and the best result was obtained when using papain at an E:S ratio of 2:100, after ultrafiltration, reaching 15.29% of di- and tripeptides, 47.83% of free amino acids and 25.73% of large peptides. Then, the inhibition activity of WPC hydrolysates was evaluated using a fractionation method by reversed-phase HPLC. The assessed parameters showedvaried effect on the AI of the ACE, resulting in percentages of inhibition between 17.29 and 91.88%. The best results were obtained using pancreatin at an E:S ratio of 0.5:100 (in the presence or absence of ultrafiltration) and 3:100 (in the presence of ultrafiltration).Keywords: whey protein concentrate; enzymatic hydrolysis; enzyme:substrate ratio; ultrafiltration; peptide profile; angiotensin-converting enzyme.