title: Reduction of Brochothrix thermosphacta on beef surfaces following immobilization of nisin in calcium alginate gels.
abstract: Lean and adipose beef carcass tissues inoculated with Brochothrix thermosphacta (BT) (approx. 4.50 log10 cfu cm-2) were left untreated (U) or treated with 100 micrograms ml-1 nisin (N), calcium alginate (A) or 100 micrograms ml-1 nisin immobilized in a calcium alginate gel (AN). Tissue samples were refrigerated after treatments and bacterial populations and nisin activity were determined at 0, 1, 2 and 7 d. U, A and N treatments of lean and adipose tissues did not suppress bacterial growth ( > 6 log10 cfu cm-2 by day 7) while treatments of lean and adipose tissues with AN suppressed bacteria ( > 2.42 log10 cfu cm-2 by day 7). Bacteriocin titres from both tissues were higher in AN vs N samples after the 7 d incubation. This study demonstrates that immobilization of nisin in a gel may be a more effective delivery system of a bacteriocin to the carcass surface than direct application.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Roman L. Hruska US Meat Animal Research Center, Clay Center, NE 68933, USA.
authors.forename: C N
authors.initials: CN
authors.lastname: Cutter
authors.forename: G R
authors.initials: GR
authors.lastname: Siragusa
mesh_terms: D000464:Alginates; D000818:Animals; D002417:Cattle; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology*; D020723:Glucuronic Acid; D006093:Gram-Positive Asporogenous Rods / Q000187:drug effects* / Q000254:growth & development; D006603:Hexuronic Acids; D008460:Meat / Q000382:microbiology*; D009561:Nisin / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000464:Alginates; D005520:Food Preservatives; D006603:Hexuronic Acids; D009561:Nisin; D020723:Glucuronic Acid