Obtenção de hidrolisados enzimáticos do concentrado protéico do soro de leite com elevado teor de di-tripeptídeos para utilização em nutrição clínica

Abstract

Protein hydrolysates are mainly used in patients with nutritional and physiological needs uncovered by traditional food. In this present work, whey protein concentrate (WPC) was used as raw matter considering its nutritional value, capacity to synthesize glutathione, stability, physical and chemical properties and laboratorial easy-handling. The aim of this work was the preparation of whey protein hydrolysates containing high di-tripeptides and free amino acid contents, as well as low amouts of large peptides. Commercial subtilisin and pancreatin were used separately, under different hydrolysis conditions and some process stages were optimized in order to reduce the scaling-up costs. The peptide profile of these hydrolysates was determined by fractionation onsize-exclusion-HPLC, followed by quantification of peptides and free amino acids by the Rapid Correct Fraction Area method. When using subtilisin, the best peptide profile was obtained using raw matter concentration of 10 %, an enzyme:substrate ratio of 4:100, after 5 h of reaction, reaching 13,34 % of di-tripeptides, 45,56 % of free amino acids and just 12,28 % of large peptides. For pancreatin, the beneficial effect on the peptide profile was observed in nine cases, and it was mainly associated with low content of large peptides (12,80 %, in average) and high amount of di-tripeptides (12,11 %, in average)and free amino acids (49,06 %, in average).