Main content area

Controlled release of nisin from Neusilin particles to enhance food safety of sour curd cheese

Szendy, Maik, Westhaeuser, Florian, Baude, Barbara, Reim, Jessica, Dähne, Lars, Noll, Matthias
Journal of food science and technology 2019 v.56 no.3 pp. 1613-1621
Listeria monocytogenes, antibacterial properties, atomization, cheesemaking, food additives, food pathogens, food safety, minimum inhibitory concentration, nisin, pH, soft cheeses
Nisin is frequently added as food additive to soft cheese to increase food safety against foodborne pathogens like Listeria monocytogenes. The goal of this study was the extension of the antimicrobial activity of nisin in sour curd cheese (SCC) by self-releasing adsorbed nisin from Neusilin UFL2 over production-based pH shift. First, the antimicrobial activity of nisin adsorbed to Neusilin UFL2 (UFL2-N) and free nisin was investigated in BHI broth at a pH range from 7.5 to 4.5 for each of six L. monocytogenes field isolates. UFL2-N showed similar minimal inhibition concentration to L. monocytogenes over time as free nisin. Distribution of nebulized, fluorescence-labelled UFL2 was homogenous on SCC surface. Thereafter, SCC surface was inoculated with L. monocytogenes and 0.004, 0.013, 0.026, and 0.132 mg mL⁻¹ UFL2-N or free nisin. In SCC, L. monocytogenes was below quantification limit at 0.132 mg mL⁻¹ UFL2-N or free nisin after 2 days of ripening. Collectively, UFL2-N enabled a slow release and antilisterial activity in vitro as well as in cheese manufacturing.