Hydrolysates From Ultrafiltrated Double-Cream Cheese Whey: Enzymatic Hydrolysis, Antioxidant, And Ace-Inhibitory Activities And Peptide Characterization

The hydrolysis conditions (enzyme:substrate [E:S] ratio and time) of a whey protein concentrate obtained by ultrafiltration of double-cream cheese whey were optimized for the production of antioxidant and angiotensin-converting enzyme (ACE) inhibitory hydrolysates; subsequently, the hydrolysates were fractionated and characterized by chromatography techniques. The results showed that the E:S ratio and time significantly affected (p < .05) the soluble protein content, free amino acids (FAA), degree of hydrolysis (DH), and antioxidant capacity. A decrease in the protein content and an increase in the FAA concentration, DH, and antioxidant activity were observed when both parameters increased. The most adequate conditions to obtain a hydrolysate with antioxidant potential were an E:S ratio of 1:20 (w/w), and time of hydrolysis of 7 hr for alcalase, 2 hr for chymotrypsin, and 6 hr for flavourzyme. After fractionation, different peptides were detected in the hydrolysates, which could contribute to antioxidant and ACE-inhibitory activities of hydrolysates. Practical applications Hydrolysates with antioxidant and angiotensin-converting enzyme-inhibitory activities were obtained from double-cream cheese whey, which could become in an industrial innovation strategy based on the use of by-products that can significantly impact on the circular economy of the dairy industry, the environment, and the production of functional compounds with potential use in the food, feed, pharmaceutical, or cosmetic industries.