Heat inactivation of Salmonella typhimurium DT104 in beef as affected by fat content.
Lett Appl Microbiol
; 30(6): 461-7, 2000 Jun.
Article
em En
| MEDLINE
| ID: mdl-10849277
ABSTRACT
The heat resistance of an eight-strain cocktail of Salmonella typhimurium DT104 was determined at 58-65 degrees C in beef containing 7, 12, 18 or 24% fat. Inoculated beef was packaged in bags completely immersed in a circulating water bath and held at 58, 60, 62.5 and 65 degrees C for a predetermined length of time. The surviving cell population was enumerated by spiral plating heat-treated samples onto tryptic soy agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. Preliminary studies on thermal inactivation of the Salmonellae isolates in chicken broth indicated no correlation between heat resistance and origin of the isolates. While linear survival curves were observed in chicken broth, inactivation kinetics in beef showed deviations from the first order kinetics, represented by an initial lag period or shoulder before any death occurred with time. Overall, increased fat levels in beef resulted in longer lag periods and lower D-values, suggesting that the lag periods must be taken into account and added to the D-values for calculating the time required at a specific temperature for achieving a specific lethality for Salm. typhimurium DT104 in beef. Thermal death times from this study will assist the retail food industry to design cooking regimes that ensure safety of beef contaminated with Salm. typhimurium DT104.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Salmonella typhimurium
/
Culinária
/
Microbiologia de Alimentos
/
Temperatura Alta
/
Produtos da Carne
Limite:
Animals
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article