Effect of processing conditions and simulated gastrointestinal digestion on the activity of angiotensin I-converting enzyme (ACE) inhibitory peptide derived from duck meat hydrolysate

In this study, the ACE-inhibitory peptide (<3kDa) was obtained through ultrafiltration of duck meat enzymatic hydrolysate. The research investigated the effect of processing conditions (heating, pH, NaCl, glucose) and simulated gastrointestinal digestion on the activity of peptide. It was found that contents of NaCl and glucose, heating temperatures (up to 100 degrees C), and heating times (20-120min) had no significant effect on the activity of peptide. The peptide attained highest activity at pH=7, while sharply declined at alkaline condition. The activity of peptide significantly increased by 9.08% than before in vitro digestion. Peptides were cleaved into smaller fragments after pepsin digestion and leading to increased exposure of internal hydrophobic residues. With further treatment of trypsin, more free amino acids were released and surface hydrophobicity was declined. The study showed that the activity of ACE-inhibitory peptide has ideal tolerance for different processing conditions and in vitro gastrointestinal digestion. RESUMENEn este estudio, se obtuvo peptido inhibidor de la ACE (<3kDa) empleando ultrafiltracion de hidrolizado enzimatico de carne de pato. La investigacion indago los efectos que las condiciones de procesamiento (calentamiento, pH, NaCl, glucosa) y la digestion gastrointestinal simulada tienen sobre la actividad del peptido. En este sentido, se encontro que los contenidos de NaCl y glucosa, las temperaturas de calentamiento (hasta 100 degrees C) y los tiempos de calentamiento (20-120min) no tuvieron efectos significativos sobre la actividad del peptido. Este alcanzo su actividad maxima a pH = 7, y la misma disminuyo bruscamente en condiciones alcalinas. La actividad del peptido aumento significativamente en 9.08% despues de la digestion in vitro. Tras la digestion con pepsina, los peptidos se escindieron en fragmentos mas pequenos, lo que dio lugar a una mayor exposicion de los residuos hidrofobos internos. El tratamiento adicional con tripsina provoco la liberacion de mas aminoacidos libres, reduciendose la hidrofobicidad de la superficie. El estudio mostro que la actividad del peptido inhibidor de la ACE muestra una tolerancia ideal a diferentes condiciones de procesamiento y a la digestion gastrointestinal in vitro.