Concentrados proteicos a partir de lactosuero ácido de queso colombiano como una fuente de hidrolizados antioxidantes obtenidos por proteólisis

Protein concentration and hydrolysis have been widely used in sweet whey to produce a variety of food products, while the use of acid whey has been limited due to its high salinity and acidity, hence this study aimed to obtain different protein concentrates from Colombian double-cream cheese acid whey by ultrafiltration (UF), salt treatment (ST), and thermal precipitation (TP); and to evaluate their potential application in the production of antioxidant hydrolysates by enzymatic hydrolysis with alcalase (ALC), chymotrypsin (CHY), and flavourzyme (FLA). Regarding the protein concentration, the UF, TP, and ST concentrates presented a protein content of 49, 75, and 53% and protein yield of 46, 28, and 43%, respectively. After enzymatic hydrolysis, the soluble protein content decreased in the UF and ST concentrates, while the free amino acid concentration increased in all concentrates. The UF and ST concentrates showed a higher degree of hydrolysis with ALC (33.76 and 33.57%, respectively) and FLA (40.35 and 31.60%, respectively). Concerning antioxidant activity, the UF and ST concentrates treated with ALC (5,675 and 5,199 µmol Trolox L-1, respectively) and CHY (4,663 and 4,419 µmol Trolox L-1, respectively) were the most effective in scavenging the ABTS radical. All the FLA hydrolysates presented higher reducing power (152-183 µmol Trolox L-1) and the UF concentrate, and its hydrolysates showed greater iron-chelating activity. In conclusion, UF and ST are valuable methods for acid whey protein recovery and concentration, which could be converted into potential antioxidant peptides by proteolytic processes.