Effect of nanovesicle-encapsulated nisin on growth of Listeria monocytogenes in milk.
Commercial nisin was encapsulated in nanovesicles (mean diameter 140 nm) prepared from partially purified soy lecithin. Nisin-loaded liposomes and unencapsulated (free) nisin were initially tested in BHI medium and skim milk inoculated with Listeria monocytogenes and incubated for 48 h at 30 degrees C. At such abuse temperature conditions, free nisin showed better inhibitory than the liposomal counterparts. Subsequently, the effect of encapsulated or free nisin was evaluated in combination with refrigeration (7 +/- 1 degrees C) in both whole (3.25% fat) and skim (0% fat) milk for up to 14 day. A decrease of 3-4 log cycles in L. monocytogenes counts was observed for free and encapsulated nisin at 0.5 mg/ml concentration. Liposome encapsulation of antimicrobial peptides may be important to overcome stability issues and interaction with food components. The utilization of nanovesicle-encapsulated nisin in combination with low temperatures appeared to be effective to control L. monocytogenes in milk, emphasizing the importance of hurdle technology to assure food safety.
da Silva Malheiros
Patrícia
P
Departamento de Ciência de Alimentos, Laboratório de Bioquímica e Microbiologia Aplicada, ICTA, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS, Brazil.
Daroit
Daniel Joner
DJ
da Silveira
Nádya Pesce
NP
Brandelli
Adriano
A
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D008081:Liposomes; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development*; D008892:Milk / Q000382:microbiology*; D009561:Nisin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D008081:Liposomes; D009561:Nisin