Optimizing the development of an antihypertensive whey hydrolysate in semi-pilot scale

Whey proteins and peptides are byproducts of dairy industry recognized for reducing risk factors of numerous diseases, including hypertension Despite the need of better use of this agroindustrial residue and the high prevalence of hypertension worldwide, whey based-products that are able to modulate blood pressure are very scarce in food and nutraceutical markets, emphasizing the need of more research regarding this theme. The development of new products requires several stages in which scaling-up the production is comprised. In this manner, the present study proposed to optimize the process of development of a new antihypertensive whey hydrolysate in semi-pilot scale, assessing the influence of drying technologies and enzyme inactivation conditions on its biofunctionality. A commercial pepsin (1.91% w/w; 0.28μU.mL-1) was used to catalyse the hydrolysis of a 88% whey protein concentrate solution (1.25%; pH2, 1M HCl; 20L). Reactions occurred for 3h at 37°C, then the enzyme was inactivated either by increasing the temperature to 80°C/5min or the pH to 7 (5M NaOH).The drying method (freeze- and spray-drying) was also assessed concerning the vasorelaxant activity, which was evaluated in rat aortic rings. Peptide profiles of the samples inactivated by temperature were more varied than the chemically inactivated ones. In all samples α-Lactalbumin was completely hydrolyzed while β-Lactoglobulin remained partially resistant. Corroborating with the chemical analyses, hydrolysates thermally inactivated showed vascular relaxations of 72.06% ± 11.36 (freeze-dried) and 81.00% ± 14.27 (spray-dried) (p>0.05), while the samples inactivated by pH reached 20.6% ± 5.4 (freeze-dried) and -9.25% ± 10.18 (spray-dried) of vascular relaxation (p>0.05), which may be possibly related to the formation of NaCl. The results showed that it was possible to develop a whey protein hydrolysate in semi-pilot scale with high antihypertensive activity using a more affordable technology to food industries