Enzymes for production of whey protein hydrolysates and other value-added products

Abstract

Whey is a byproduct of dairy industries, the aqueous portion which separates from cheese during the coagulation of milk.It represents approximately 85–95% of milk’s volume and retains much of its nutrients, including functional proteins andpeptides, lipids, lactose, minerals, and vitamins. Due to its composition, mainly proteins and lactose, it can be considereda raw material for value-added products. Whey-derived products are often used to supplement food, as they have shownseveral physiological effects on the body. Whey protein hydrolysates are reported to have different activities, including antihypertensive,antioxidant, antithrombotic, opioid, antimicrobial, cytomodulatory, and immuno-modulatory. On the otherhand, galactooligosaccharides obtained from lactose can be used as prebiotic for beneficial microorganisms for the humangastrointestinal tract. All these compounds can be obtained through physicochemical, microbial, or enzymatic treatments.Particularly, enzymatic processes have the advantage of being highly selective, more stable than chemical transformations,and less polluting, making that the global enzyme market grow at accelerated rates. The sources and different products associatedwith the most used enzymes are particularly highlighted in this review. Moreover, we discuss metagenomics as a tool toidentify novel proteolytic enzymes, from both cultivable and uncultivable microorganisms, which are expected to have newinteresting activities. Finally enzymes for the transformation of whey sugar are reviewed. In this sense, carbozymes withß-galactosidase activity are capable of lactose hydrolysis, to obtain free monomers, and transgalactosylation for prebioticsproduction.