Abstract
Possible contamination by Staphylococcus aureus of the production environment and of the meat of a canned meat production factory was analysed. A total of 108 samples were taken from nine critical control points, 13 of them were positive for S. aureus. None of the isolates produced enterotoxins. To determine how much time can elapse between can seaming and sterilisation in the autoclave without any risk of enterotoxin production by S. aureus, the growth and enterotoxin production of three enterotoxin A producing strains of S. aureus (one ATCC strain and two field strains) in canned meat before sterilisation was investigated at three different temperatures (37, 20 and 10 °C). Two types of meat were used, one with and one without sodium nitrite. In the canned products, the spiked bacteria spread throughout the meat and reached high levels. Enterotoxin production was shown to start 10 hours after incubation at 37 °C and after 48 h after incubation at 20 °C; the production of enterotoxin was always detected in the transition between the exponential and the stationary growth phase. At 10 °C, the enterotoxin was never detected. The statistical analysis of the data showed that the difference between the two different types of meat was not statistically significant (p value > 0.05). Since it is well known that following heat treatment, staphylococcal enterotoxins, although still active (in in vivo assays), can be undetectable (loss of serological recognition) depending on the food matrix and pH, it is quite difficult to foresee the impact of heat treatment on enterotoxin activity. Therefore, although the bacteria are eliminated, the toxins may remain and cause food poisoning. The significance of the results of this study towards implementing good manufacturing practices and hazard analysis critical control points in a canned meat factory are discussed with reference to the management of pre-retorting steps after seaming.
Highlights
Processed meats are protein-rich foods, which can serve as an excellent culture media for the growth of microorganisms [1]
We investigated the behaviour of three enterotoxigenic S. aureus strains spiked in canned meat with and without sodium nitrite at different temperatures, in order to implement good manufacturing practices and the hazard analysis and critical control point system at the factory, with specific attention to the management of pre-retorting steps after seaming
The growth profile and enterotoxin production of the three S. aureus strains tested in canned meat is similar to what is reported by other studies
Summary
Processed meats are protein-rich foods, which can serve as an excellent culture media for the growth of microorganisms [1]. Contamination by microorganisms can be exacerbated during the canning process, especially if the end product presents low acidity and is maintained in conditions of temperature abuse [2]. There are several bacterial species, which are known to be able to contaminate canned meat, e.g., Clostridium spp., Listeria spp., Bacillus spp., Escherichia coli and Staphylococcus aureus [3,4,5]. S. aureus represents a serious hazard for the end consumer, as it is able to produce enterotoxins, which are stable at high temperatures (e.g., Crude enterotoxin A remains active at 100 ◦ C for 2 h in broth and at 121 ◦ C for 28 min in mushrooms) and can resist under many environmental conditions (low pH, freezing, drying), in which S. aureus strains do not survive [7,8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
