Inhibition of Listeria monocytogenes growth in Cheddar cheese by an anionic peptides-enriched extract from whey proteins

The efficacy of an anionic peptides-enriched extract (APEE), produced by nanofiltration of a tryptic hydrolysate from whey proteins, to inhibit the growth of Listeria innocua and Listeria monocytogenes in reconstituted Cheddar cheese was studied. The antimicrobial activity of APEE in reconstituted cheese was greater against L. monocytogenes than L. innocua and was higher in storage at 30 °C than at 4 °C. The combination of 20 mg g−1 of APEE and 1.75% salt/moisture (S/M) in cheeses incubated for 7 days at 30 °C was the most efficient condition to inhibit the growth of Listeria. Using these conditions, L. monocytogenes counts were significantly reduced by 1.1 and 1.5 log cfu g−1, compared with cheeses without APEE and prepared with lactococci at 1.75 and 3.5% S/M, respectively. These results suggest that antimicrobial anionic peptides from whey proteins can contribute to control pathogen in reduced-salt Cheddar cheeses.