title: Inhibition of toxigenesis of group II (nonproteolytic) Clostridium botulinum type B in meat products by using a reduced level of nitrite.
abstract: The effect of three different concentrations of sodium nitrite (0, 75, and 120 mg/kg) on growth and toxigenesis of group II (nonproteolytic) Clostridium botulinum type B was studied in Finnish wiener-type sausage, bologna-type sausage, and cooked ham. A low level of inoculum  (2.0 log CFU/g) was used for wiener-type sausage and bologna-type sausage, and both low (2.0 log CFU/g) and high (4.0 log CFU/g) levels were used for cooked ham. The products were formulated and processed under simulated commercial conditions and stored at 8°C for 5 weeks. C. botulinum  counts were determined in five replicate samples of each nitrite concentration at 1, 3, and 5 weeks after thermal processing. All samples were positive for C. botulinum type B. The highest C. botulinum counts were detected in nitrite-free products. Toxigenesis was observed in  nitrite-free products during storage, but products containing either 75 or 120 mg/kg nitrite remained nontoxic during the 5-week study period, suggesting that spores surviving the heat treatment were unable to germinate and develop into a toxic culture in the presence of nitrite. The results  suggest that the safety of processed meat products with respect to group II C. botulinum type B can be maintained even with a reduced concentration (75 mg/kg) of sodium nitrite.
authors.affiliation: Department of Food Hygiene and Environmental Health, P.O. Box 66, FI-00014 University of Helsinki, Helsinki, Finland. riikka.keto-timonen@helsinki.fi
authors.forename: Riikka
authors.initials: R
authors.lastname: Keto-Timonen
authors.forename: Miia
authors.initials: M
authors.lastname: Lindström
authors.forename: Eero
authors.initials: E
authors.lastname: Puolanne
authors.forename: Markku
authors.initials: M
authors.lastname: Niemistö
authors.forename: Hannu
authors.initials: H
authors.lastname: Korkeala
mesh_terms: D001905:Botulinum Toxins / Q000032:analysis; D047014:Clostridium botulinum type B / Q000187:drug effects* / Q000502:physiology; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D008461:Meat Products / Q000382:microbiology*; D009573:Nitrites / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors
chemical_list: D009573:Nitrites; D001905:Botulinum Toxins