Screening and Application of Fungal Proteases for Goat Casein Hydrolysis Towards the Development of Bioactive Hydrolysates

Five protease-producing and non-mycotoxin-producing fungi (Mucor subtilissimus URM 4133, Mucor sp. URM 4146, Mucor guilliermondii URM 5848, Aspergillus viride-nutans URM 6629 and Penicillium decumbens URM 6018) were used for hydrolysis of caprine casein. Peptides obtained from different fungi were separated on two fractions: molecular mass (MM) < 3 kDa and MM from 3 to 10 kDa, and the peptide fractions were investigated for antimicrobial, antioxidant and antihypertensive bioactive properties. All the 3 to 10 kDa fractions of all fungi were able to inhibit the growth of the three Gram-negative bacteria and the hydrolysate from URM 5848 inhibited all bacteria, except the bacteria Gram-positive Enterococcus faecalis. All hydrolysates with the peptides between 3 and 10 kDa possessed a strong scavenging capacity for ABTS•+ [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals, in which URM 5848 (100