Production of antibacterial fraction from Atlantic mackerel (Scomber scombrus) and its processing by-products using commercial enzymes

Atlantic mackerel and its processing wastes were hydrolyzed separately using four commercial proteases, namely: Protamex, Neutrase, papain, and Flavourzyme. Mackerel and its by-products hydrolysates were rich in essential amino acids such as lysine, leucine and phenylalanine (3.44-7.81 mg g(-1)). Hydrolysis using protamex, neutrase or papain generated a high number of small peptides (300-700 Da). Both crude hydrolysates of mackerel and its by-products (1 mg mL(-1)) inhibited at least 40% of Listeria innocua HPB13 and Escherichia coli MC4100 growth, with crude by-products hydrolysate obtained by papain and neutrase being the most antilisterial with 69.7% and 65.2% of inhibition, respectively. Dose-dependent inhibition curves were obtained and complete inhibition of both L. innocua and E. coli was obtained after acetone fractionation of whole mackerel and its by-products hydrolyzed with protamex at 20 mg mL(-1). Due to its high nutritional value, coupled with excellent functional properties mackerel by-products are of interest as functional foods. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.