Mariana Wanessa Santana de Souza

Analysis of whey protein hydrolysates: peptide profile and ACE inhibitory activity

O objetivo deste estudo foi preparar hidrolisados enzimaticos do concentrado proteico do soro de leite com perfil peptidico nutricionalmente adequado e com capacidade para inibir a atividade da enzima conversora da angiotensina (ECA). Os efeitos do tipo de enzima usado (pancreatina ou papaina), da relacao enzima:substrato (E:S=0,5:100, 1:100, 2:100 e 3:100) e do uso da ultrafiltracao (UF) foram investigados. O fracionamento dos peptideos foi feito por CLAE de exclusao molecular e a quantificacao dos componentes das fracoes cromatograficas foi realizada pelo metodo da Area Corrigida da Fracao. A atividade inibitoria da ECA (AI-ECA) foi determinada por CLAE de fase reversa. Todos os parâmetros testados afetaram tanto o perfil peptidico quanto a AI-ECA. O melhor perfil peptidico foi atingido para os hidrolisados obtidos com papaina, enquanto a pancreatina foi mais vantajosa em termos da AI-ECA. O efeito benefico do uso de menor relacao E:S sobre o perfil peptidico e a AI-ECA foi observado para ambas as enzimas dependendo das condicoes usadas para o preparo dos hidrolisados. O efeito benefico da ausencia da UF sobre o perfil peptidico foi observado em alguns casos para pancreatina e papaina. No entanto, a ausencia da UF produziu maior AI-ECA somente quando a papaina foi usada.

Production of Ace-Inhibitory Whey Protein Concentrate Hydrolysates: Use of Pancreatin and Papain

Whey protein concentrate hydrolysates, capable of inhibiting the activity of angiotensin-converting enzyme, were prepared in the present study. Several parameters, such as type of enzyme, enzyme:substrate ratio, and use of ultrafiltration were evaluated. The angiotensin-converting enzyme inhibitory activity was observed only after the enzymatic treatment and high rates of inhibition were obtained, ranging from 17.29 to 91.88%. Most hydrolysates obtained with pancreatin showed higher angiotensin-converting enzyme inhibitory activity than those obtained with papain both in the absence and presence of ultrafiltration. The smallest enzyme:substrate ratio for pancreatin resulted in better angiotensin-converting enzyme inhibitory activity values. The use of ultrafiltration proved to be disadvantageous for inhibitory activity of hydrolysates obtained with papain.

Effect of Some Hydrolytic Parameters in the Action of Subtilisin and Pancreatin on Whey Protein Concentrate

Abstract In this work, the influence of some reactional parameters in the hydrolysis of whey protein concentrate (WPC) was evaluated, in terms of the nutritional quality of peptide profiles of the hydrolysates as well as the reduction of costs for scaling-up the process. Two enzymes (subtilisin and pancreatin) were used for preparing 18 hydrolysates, using different E:S ratios and reaction times, and the distribution of peptides according to chain length was analyzed by size-exclusion chromatography. The studied parameters affected the peptide profiles of WPC hydrolysates and the best result was similar for subtilisin and pancreatin, both using an E:S ratio of 4:100, after 5 h and 10 h, respectively. In these conditions, these enzymes gave rise to the smallest large peptide contents (12.28% and 12.34%, respectively) and one of the highest amount of di- and tripeptides (13.34% and 13.00%, respectively) as well as of free amino acids (45.56% and 47.26%, respectively). However, in terms of number of samples the action of pancreatin was more advantageous than subtilisin, since among the nine hydrolysates, four showed appropriate peptide profiles (P1, P2, P5, and P6), from the nutritional point of view, while the same happened only with one hydrolysate prepared by using subtilisin (S3). Also, the economical advantage of using smaller E:S ratio and reaction time was observed in several cases for both enzymes.