title: Effect of the lactoperoxidase system on Listeria monocytogenes behavior in raw milk at refrigeration temperatures.
abstract: Activity of raw milk lactoperoxidase-thiocyanate-hydrogen peroxide (LP) system on four Listeria monocytogenes strains at refrigeration temperatures after addition of 0.25 mM sodium thiocyanate and 0.25 mM hydrogen peroxide was studied. The LP system exhibited a bactericidal activity against L. monocytogenes at 4 and 8 degrees C; the activity was dependent on temperature, length of incubation, and strain of L. monocytogenes tested. D values in activated-LP system milk for the four strains tested ranged from 4.1 to 11.2 days at 4 degrees C and from 4.4 to 9.7 days at 8 degrees C. The lactoperoxidase level in raw milk declined during a 7-day incubation, the decrease being more pronounced at 8 degrees C than at 4 degrees C and in control milk than in activated-LP system milk. The thiocyanate concentration decreased considerably in activated-LP system milk at both temperatures during the first 8 h of incubation. LP system activation was shown to be a feasible procedure for controlling development of L. monocytogenes in raw milk at refrigeration temperatures.
authors.affiliation: Departamento de Producción y Tecnología de Alimentos, CIT-INIA, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Gaya
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: M
authors.initials: M
authors.lastname: Nuñez
mesh_terms: D000818:Animals; D003080:Cold Temperature; D015169:Colony Count, Microbial; D004355:Drug Stability; D004795:Enzyme Stability; D005516:Food Microbiology; D007784:Lactoperoxidase / Q000737:chemistry / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D008892:Milk / Q000032:analysis / Q000382:microbiology*; D012034:Refrigeration; D013861:Thiocyanates / Q000494:pharmacology
chemical_list: D013861:Thiocyanates; D007784:Lactoperoxidase; C031760:thiocyanate