Bioactivity and peptide profile of whey protein hydrolysates obtained from Colombian double-cream cheese production and their products after gastrointestinal digestion

Peptides obtained from whey proteins have been associated with different biological properties, but most peptides are usually degraded during the digestive process. In this work, hydrolysates were prepared from a whey protein concentrate obtained by ultrafiltration of Colombian traditional cheese whey and subsequent enzymatic hydrolysis using alcalase, chymotrypsin and flavourzyme. The antioxidant and angiotensin-converting enzyme (ACE) inhibitory properties were evaluated, and peptide profile was determined by ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Changes in the above biological properties and peptide profile after simulated gastrointestinal digestion were then investigated. Before enzymatic hydrolysis, the alcalase hydrolysate showed higher 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity, whereas an inhibition greater than 85% of ACE activity was observed for the alcalase and chymotrypsin hydrolysates. In both tests, the flavourzyme hydrolysates showed lower activities. Different changes in the above biological activities were observed after gastrointestinal digestion of the alcalase and chymotrypsin hydrolysates: ABTS radical scavenging ability increased, whereas ACE inhibitory capacity decreased significantly. The alcalase hydrolysate obtained from ultrafiltrated whey protein concentrate showed high antioxidant and ACE inhibition capacities and higher survivability of peptides after in vitro gastrointestinal digestion.