Manufacture of bioactive peptide-rich concentrates from whey: characterization of pilot process

This work was focused on the manufacture, at pilot scale, of cow whey protein and peptide concentrates, using selective filtration techniques—associated with hydrolysis brought about by proteolytic enzymes from Cynara cardunculus aqueous extracts, using as (optimal) conditions an enzyme/substrate ratio of 1.6% v/v, a pH of 5.2, a temperature of 55 °C and an incubation time of 7 h. The profiles of proteins and peptides were assessed by liquid chromatography and electrophoresis; ca. 87% of α-lactalbumin was hydrolyzed, but essentially no degradation of β-lactoglobulin (β-Lg) was observed. A bioactive peptide concentrate, its fraction below 3 kDa and a β-Lg-rich fraction were obtained as final products, containing ca. 73, 43 and 91% w/w protein (on a total solid mass basis). All these fractions were low in lactose and salt, and their microbial loads were reduced. Said fractions are high added-value products, so they can be used as nutritional and functional ingredients—thus yielding an economically viable alternative for upgrade of whey.