Behavior of spoilage bacteria and Salmonella enterica subspecies enterica O:4,5 in vacuum-packaged beef during refrigeration

Comportamento de bactérias deteriorantes e Salmonella enterica subespécie entérica O:4,5 em carne bovina embalada a vácuo durante refrigeração

ABSTRACT:

In this study, the kinetic parameters of mesophilic, psychrotrophic and lactic acid bacteria in vacuum-packed beef at 1 °C and 4 °C were estimated from experimental growth curves produced by samples stored during 21 and 60 days, respectively. In a separate experiment, the survival of multidrug resistant (MDR) Salmonella enterica O:4,5 at 1°C was also characterized. The shelf-life of vacuum-packed beef stored at 4 °C was estimated at 16.1 days (95% CI: 14.8 - 17.3 days), whereas at 1 °C it was longer than 21 days because the mesophiles count estimated towards the end of the experiment was 12.5 ln CFU.g^-1 (95% CI: 11.8 - 13.3 ln CFU.g^-1) which is lower than the shelf-life reference value. At 1 °C, inoculated Salmonella was reduced in 6.61 ln CFU.g^-1 (2.87 log CFU.g^-1). These results demonstrated the importance of establishing in legislation, especially in Brazil, standard values of deteriorating microorganisms in beef for maintaining product quality.

Key words:
deteriorating microorganisms; meat quality; predictive microbiology; Salmonella