SQU study reveals bacterial variations in cafeteria sandwiches

MUSCAT: Ameer al Rawahi, a student in the Department of Food Science and Nutrition at Sultan Qaboos University’s College of Agricultural and Marine Sciences, explored a question often overlooked in everyday food consumption: how safe are ready-made sandwiches sold in cafeterias and shops?
Sandwiches are widely considered a convenient, quick and appetising meal option. Their familiar appearance often creates a sense of reassurance.
However, behind this simplicity lies a more complex food safety reality. Variations in ingredients, reliance on manual preparation, and potential breaks in the cold chain can all influence microbial safety and determine whether such meals remain safe for consumption.
Motivated by an interest in food safety, Al Rawahi, under the supervision of Dr Ismail al Balushi, conducted a field-based study to assess the microbial quality of ready-made sandwiches.
The research involved the collection of 60 samples from cafés and shops across Muscat Governorate. The samples included egg, chicken, tuna and meat sandwiches, which were analysed to evaluate bacterial contamination levels and overall microbiological safety.
Laboratory findings showed noticeable variation in bacterial counts across the different sandwich types. Meat sandwiches recorded the highest total bacterial load, followed by tuna, chicken and egg sandwiches.
Some samples also reflected microbial indicators suggesting differences in hygiene practices during preparation and handling.
However, the study confirmed the absence of Salmonella bacteria in all tested samples, an encouraging result that points to generally safe consumption levels.
Based on the Food Standards Australia New Zealand (FSANZ) guidelines, most samples fell within acceptable microbiological limits, indicating that while variations exist, the products largely remain safe for public consumption.
The study recommends expanding future research to include a larger sample size and a broader range of pathogenic bacteria. Such efforts would help provide a more comprehensive understanding of ready-made food safety, strengthen regulatory monitoring and support improvements in hygiene standards across food outlets.