Hydrolysis of sheep's milk whey concentrate by membrane and evaluation of the antioxidant and antimicrobial properties

Abstract

Sheep´s milk whey is an important source of protein and present functional properties. Studies related to the concentration of sheep´s milk whey proteins are still scarce in the literature. In order to improve not only the chemical, physical and functional properties of foods, but also the absorption characteristics of the proteins, without impairing the nutritional value, enzymatic hydrolysis process can be used. From the hydrolysis of whey proteins are generated bioactive peptides that have antioxidant and microbial activity. The aim of this study was to produce sheep's milk whey concentrate by ultrafiltration/diafiltration process and to perform the enzymatic hydrolysis using corolase H-pH in different times (1, 2, 3, 4, 5 and 6 h) and evaluate the degree of hydrolysis, antioxidant and antimicrobial potential and protein fractions. The protein value found for diafiltered sheep's milk whey was 84% with protein fractions corresponded to β-lactoglobulin, α-lactalbumin. The values of degree of hydrolysis were 12.07 and 15.55% in the evaluated times. The highest antimicrobial activity was observed in 1 h for Salmonella choleraesuise and Listeria monocytogenes and the high antioxidant activity was obtained for the maximum concentration tested (3.0 mg mL/L) in 6 h of hydrolysis. Therefore the diafiltered sheep's milk whey hydrolysed presented antimicrobial and antioxidant characteristics, presenting potential of application in foods.