Staphylococcus aureus was found high in one Swiss roll sample at a level that might cause food poisoning.
In collaboration with the Centre for Food Safety (CFS), the Consumer Council have jointly conducted a test on a collection of 114 sweet foods sourced from various eatery outlets across the territory - Chinese restaurants, Thai restaurants, cafés, coffee shops, bakeries, dessert specialists and supermarkets.
The test aimed at investigating the microbiological quality of these foodstuffs.
One sample of Swiss roll was detected to contain Staphylococcus aureus of 500,000 cfu/g, rendering it unsafe to eat.
Another 7 samples were found to have aerobic colony counts of between 150,000 cfu/g and 2,000,000 cfu/g, exceeding the "acceptable" limit of below 100,000 cfu/g for Food Category 2 stipulated in the Microbiological Guidelines for Ready-to-eat Food (the Guidelines) established by the CFS
In general, sweet foods that do not contain specific ingredients such as dairy cream, cheese, raw fruits and fresh juices are classified into Food Category 2. They include egg tarts, coconut tarts and most of the Chinese style sweet soups, and Chinese and Thai style puddings.
Staphylococcus aureus are bacteria commonly present in the nasal passage, throat, hair and skin of healthy individuals. They can be passed from men to foods during the preparation processes, especially when proper food handling practices are not adopted. The bacteria can be destroyed during general cooking procedures, but the toxins produced are resistant to heat and may remain in food causing food poisoning.
The onset of symptoms in staphylococcal food poisoning is usually rapid and in many cases acute. Common symptoms include vomiting, diarrhea, abdominal cramping and prostration. The ailments usually last for one to two days, but longer in severe cases.
According to the Guidelines, the Swiss roll sample with Staphylococcus aureus content (500,000 cfu/g) was classified as Class D, the lowest in the microbiological quality classification.
A sample classified as of Class D in microbiological quality means that it contains unacceptable level of specific pathogen that is potentially hazardous to the consumer.
Warning was issued by the Food and Environmental Hygiene Department (FEHD) to the bakery concerned and sale of Swiss rolls was not detected during the follow-up visits.
The 7 samples with excessive aerobic colony counts were classified as Class C, indicating a sub-optimal microbiological quality and there is need for improvements on the hygienic conditions.
The FEHD has given health advice to the licensees of the food premises concerned, and has taken follow-up samples and noted the improvements.
The causes for poor microbiological quality could be improper handling during the food preparation processes, for example, contamination by other sources after production, prolonged storage at room temperature or unhygienic practices of the food handlers.
Overall, the test found approximately 7% (8 out of 114) of the samples to be of either Class C or Class D in microbiological quality. The majorities (93%) of the test samples were considered to be satisfactory (Class A) or acceptable (Class B) in microbiological quality.
According to the Department of Health's statistics, there were 232 outbreaks of bacterial food poisoning affecting 837 people in 2010.
Consumers and restaurant operators alike should not take the problem of bacterial food poisoning lightly.
Consumers are advised to take heed of the following:
- Choose and patronize hygienic and reliable licensed food premises.
- Consume sweet foods as soon as possible.
- Store sweet foods not immediately consumed at 4℃ or below such as in a refrigerator.
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