Enzyme inactivation and drying technologies influencing the vasorelaxant activity of a whey protein hydrolysate in semi-pilot scale

A vasorelaxant whey hydrolysate at semi-pilot scale was generated, assessing the influence between two different enzyme inactivation conditions (pH and temperature) and drying technologies (freeze- and spray-drying). Hydrolysis was performed with 1.25% (w/v) whey protein concentrate solution and 1.91% (w/w) pepsin (pH 2, 3 h, 37 °C). Reactions were stopped either by increasing the pH to 7 (5 m NaOH) or by heating the solution at 80 °C for 5 min. Thermally inactivated samples induced a vascular relaxation ex vivo above 70%, while the chemically inactivated ones reached only 20%. Both drying technologies were effective in maintaining the bioactivity of the hydrolysate. These results brought the possibility of developing a whey-based product with high vasorelaxant potential in semi-pilot scale; thermal treatment followed by spray drying seemed to be the more affordable alternative for food and nutraceutical industries to generate this bioactive product.