title: Inhibition of nonproteolytic, psychrotrophic clostridia and anaerobic sporeformers by sodium diacetate and sodium lactate in cook-in-bag turkey breast.
abstract: A nonproteolytic, psychrotrophic Clostridium isolate, designated strain OMFRI1, was recovered from cook-in-bag turkey breasts (CIBTB) that displayed an intense pink discoloration and an off-odor following extended refrigerated storage. The viability of strain OMFRI1 in CIBTB containing sodium diacetate (at 0, 0.25, and 0.5%) and/or sodium lactate (at 0, 1.25, and 2.5%) was subsequently evaluated. Raw CIBTB batter was inoculated with 9 to 30 spores of strain OMFRI1 per g, vacuum packaged, cooked to an instantaneous internal temperature of 71.1 degrees C, chilled, and incubated at 4 degrees C for up to 22 weeks. In the absence of food-grade antimicrobial agents, spoilage (i.e., an off-odor) occurred within 6 weeks, and anaerobic plate counts reached 6.6 log10 CFU/g. The CIBTB containing sodium diacetate (0.25%) and that containing sodium lactate (1.25%) required 12 weeks for spoilage to occur and for anaerobic plate counts to reach 7.0 and 6.0 log10 CFU/g, respectively. When sodium diacetate (0.25%) and sodium lactate (1.25%) were used in combination, no off-odor was detected and anaerobic plate counts did not exceed 2.3 log10 CFU/g over 22 weeks of storage at 4 degrees C. In related experiments, sodium diacetate (at 0, 0.25, and 0.5%), sodium lactate (at 0, 1.25, and 2.5%), and combinations of both ingredients were evaluated in uninoculated CIBTB incubated at 25 degrees C for up to 22 days. In the absence of antimicrobial agents and in CIBTB containing sodium diacetate (0.5%), spoilage occurred within 8 days and anaerobic plate counts reached 6.8 and 6.6 log10 CFU/g, respectively. Samples of CIBTB containing sodium lactate (2.5%) showed signs of spoilage within 22 days, and anaerobic plate counts for these samples ranged from < or = 1.0 to 6.3 log10 CFU/g. In CIBTB containing both sodium lactate (2.5%) and sodium diacetate (0.25%), spoilage was not evident and anaerobic plate counts were < or = 1.0 log10 CFU/g within 22 days. These data validate the efficacy of sodium lactate and sodium diacetate in extending the shelf life of CIBTB.
authors.affiliation: Department of Food Microbiology and Toxicology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Meyer
authors.forename: J G
authors.initials: JG
authors.lastname: Cerveny
authors.forename: J B
authors.initials: JB
authors.lastname: Luchansky
mesh_terms: D000818:Animals; D003013:Clostridium / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005511:Food Handling / Q000379:methods; D005519:Food Preservation / Q000379:methods*; D008461:Meat Products / Q000382:microbiology*; D009812:Odorants / Q000032:analysis; D019346:Sodium Acetate / Q000494:pharmacology*; D019354:Sodium Lactate / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000254:growth & development; D013696:Temperature; D013997:Time Factors; D014422:Turkeys
chemical_list: D019346:Sodium Acetate; D019354:Sodium Lactate