title: Potassium lactate combined with sodium diacetate can inhibit growth of Listeria monocytogenes in vacuum-packed cold-smoked salmon and has no adverse sensory effects.
abstract: Growth of Listeria monocytogenes in ready-to-eat fish products such as cold-smoked salmon is an important food safety issue. The objective of this study was to evaluate the antilisterial activity of potassium lactate (PL) in combination with sodium acetate (SA) or sodium diacetate (SDA) in cold-smoked salmon and to determine whether these compounds could be incorporated easily into the formulations and technology currently used by processors. A commercial brine injector was used to inject salmon filets with either saturated saline brine or saturated saline brine supplemented with combinations of PL and SA (PURASAL Opti. Form PA 4) or PL and SDA (PURASAL Opti. Form PD 4). In the brine-injected cold-smoked salmon, 2.1% (water phase) PL and 0.12% (water phase) SDA delayed the growth of L. monocytogenes for up to 42 days of vacuum-packaged storage at 10 degrees C. Storage at 25 degrees C for 6 h resulted in only a 1-log CFU/g increase in L. monocytogenes. Treatments with lower concentrations of PL and SDA or similar concentrations of PL and SA resulted in an extended lag phase and slower growth of L. monocytogenes. It was not possible to incorporate more than 2% (water phase) PL while ensuring a minimum of 3% (water phase) NaCl in the finished product because PL decreased the solubility of NaCl. Sensory analyses revealed that the preservatives did not negatively affect flavor or odor. The combination of PL and SDA is therefore a viable technology for preventing L. monocytogenes growth on cold-smoked salmon.
authors.affiliation: Department of Seafood Research, Danish Institute for Fisheries Research, Søltofts Plads, DTU Buliding 221, DK-2800 Kgs. Lyngby, Denmark. bfv@difres.dk
authors.forename: Birte Fonnesbech
authors.initials: BF
authors.lastname: Vogel
authors.forename: Yoke Yin
authors.initials: YY
authors.lastname: Ng
authors.forename: Grethe
authors.initials: G
authors.lastname: Hyldig
authors.forename: Mona
authors.initials: M
authors.lastname: Mohr
authors.forename: Lone
authors.initials: L
authors.lastname: Gram
mesh_terms: D000818:Animals; D003080:Cold Temperature; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods; D005520:Food Preservatives / Q000494:pharmacology*; D006801:Humans; D007773:Lactates / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D012474:Salmon / Q000382:microbiology*; D017747:Seafood / Q000382:microbiology*; D019346:Sodium Acetate / Q000494:pharmacology; D013649:Taste; D013696:Temperature; D013997:Time Factors; D014618:Vacuum
chemical_list: D005520:Food Preservatives; D007773:Lactates; D019346:Sodium Acetate