Effect of digestive enzymes on the bioactive properties of goat milk protein hydrolysates

The aim of this research was to study the influence of the gastrointestinal digestion on the bioactivity of goat milk protein hydrolysates prepared with subtilisin, trypsin and a combination of these two enzymes. All hydrolysates had excellent angiotensin converting enzyme (ACE) inhibitory activity, antioxidant activity and bile acid-binding capacity. Peptide profiles and bioactivities were mainly altered during the intestinal digestion, whereas the effect of the gastric digestion was negligible. The influence of the intestinal digestion varied depending on the hydrolysate and the bioactivity studied. In the case of ACE inhibitory activity, it exclusively decreased when peptides were produced with trypsin. In contrast, antioxidant activity and bile acid-binding capacity improved after the gastrointestinal digestion, regardless the enzymatic treatment conducted. Hydrolysis employing mixtures of subtilisin and trypsin is considered a good approach to produce peptides that maintain, or even enhance, their bioactivity after digestion.