Food sampling
Why is sampling carried out?
Sampling is an important way of assessing the safety of food produced by a business and also the safety of the environment where food is produced or manufactured.
What types of samples are taken?
The Food Safety team undertakes microbiological sampling. Usually this will be informal sampling which involves the officer taking samples of food or environmental swabs.
Will I always know if a sample has been taken?
Usually the officer will identify themselves, as they will need to enter the food production area to obtain samples and swabs. Occasionally, however, officers will take samples without announcing their identity. This is so observations can be made of normal handling practices when staff are not under the scrutiny of an inspection.
When will I receive a sampling visit?
The authority has a routine sampling programme. Samples may be taken as part of an inspection, in relation to a complaint or as part of a local or national sampling programme. Sampling is usually based upon risk, so a business which handles more open high risk foods is more likely to receive a sampling visit than a low risk business.
What happens to the sample once the officer has visited?
The sample is submitted to the Health Protection Agency laboratory for microbiological examination.
When will I get to know a sampling result?
It is the policy of this department to notify all businesses in writing of their sample results. Even those businesses which have been subject to anonymous sampling will be notified of results.
What happens if my results are unsatisfactory?
We are normally notified by telephone if the laboratory isolates high levels of indicator or pathogenic organisms (potentially harmful bacteria). We would work with the business to try and identify the source of the problem. We may take further formal food samples.
What do the sample results in my letter mean?
An explanatory leaflet should be enclosed with your letter. It explains about your results and any action you may need to take if your sample is considered borderline or unsatisfactory.
You can also read the guidance about sample results below.
Where can I obtain further information about sampling?
For further information on food sampling contact the Food Safety team.
Food sample results - a guide to understanding microbiological results
Why is Food Sampling undertaken?
Food sampling is undertaken to assess the safety of foods produced by food businesses throughout the district. This leaflet is intended to try to explain about the different bacteria which may have been found in food you have produced and what to do to reduce the risk of them getting in your food again.
Borderline results are neither satisfactory nor unsatisfactory. They are on the upper limit of acceptability and indicate the potential for the development of public health problems and of unacceptable risk. Where results are considered borderline action as indicated in these guidelines must be considered.
Aerobic Colony Count at 30°C
This is an indication of the total number of bacteria in a food at 30°C. Some foods naturally have a high count, such as yoghurt or cheeses. However, for most foods there is an upper acceptable limit, beyond which the count is considered unsatisfactory.
A high count is usually the result of poor handling practices, poor temperature control or poor stock rotation. These all need examining and changes implemented.
Staphylococcus aureus (Staph. aureus)
This bacterium is usually associated with poor personal hygiene issues. The bacterium is found in the nose and mouth of humans and also in uncovered cuts and boils. It is important to ensure good standards of personal hygiene at all times and to discourage bad habits. Good hand-washing regimes should be implemented and cuts, boils and open wounds should be covered by a blue detectable plaster. Cross contamination should be avoided and all food which needs chilling should be chilled.
Escherichia coli (E. coli)
This organism is common in the gut of animals, including humans. Raw meat can become contaminated during the slaughter of animals. The presence of E. coli in cooked food indicates poor handling practices, cross contamination from raw foods (particularly raw meats), inadequate cooking and poor chill storage which allows the organism to grow.
Steps should be taken to check these practices within your business and to review and document them should they be inadequate.
E. coli O157
This strain of E. coli can cause serious illness when ingested. Fortunately it is relatively rare. However, it is essential that the steps outlined above are put in place and that all meat products, for example burgers, stews, curries, gravies and meat pies, are thoroughly cooked to ensure the organism is destroyed.
Clostridium perfringens (C.perfringens)
This food poisoning organism is widely distributed in the environment and foods, and forms part of the normal gut flora in man and animals. When it is found in foods it is usually as a result of poor food handling practices and inadequate cooking procedures. It is usually associated with stews, gravies and rolled joints.
To reduce the risk of this organism contaminating food, it is important to ensure that raw and cooked foods are stored separately, that good personal hygiene is maintained, and that food is cooked thoroughly and cooled rapidly. Stirring food, such as stews, during cooking, will allow for even distribution of heat throughout the food.
Bacillus cereus (B. cereus)
This bacterium is usually found in cereals (especially rice), dust and soil. It is usually associated with poor cooking practices.
To reduce the risk of this bacterium contaminating your food, you need to ensure that you cook food thoroughly and cool food rapidly. Where large batches of food are produced, portioning into smaller amounts can help the cooling process. If food is re-heated, then this should be done thoroughly. It is important to avoid cross contamination.
Salmonella species
Salmonella bacteria are usually associated with the intestines of animals and birds. It is not acceptable for any of these bacteria to be present in food.
Survival of this bacteria in food is usually due to inadequate cooking, poor standards of hygiene, and cross contamination.
It is important to ensure that frozen foods are thoroughly defrosted prior to cooking, especially poultry. Pets should be excluded from the food preparation area. Standards of personal hygiene should be reviewed and raw and cooked foods should be kept separate.
Listeria species (including Listeria monocytogenes)
These organisms are found throughout the environment and are capable of growing at refrigeration temperatures. They are often associated with salads, pates and soft cheeses. It is important that foods are thoroughly cooked, chilled and kept under refrigeration where appropriate. Cooked hygienic practices are essential, including thorough cleaning of equipment and surfaces.
Campylobacter species
This organism should not be present in food. It is usually found in the intestines of animals and is particularly associated with poultry. It’s presence in food is usually associated with cross contamination and inadequate cooking.
It is important to ensure that food is cooked for the correct time and at the correct temperature. Cross contamination needs to be avoided and good standards of hygiene should be maintained throughout.
Enterobacteriaceae
This is a family of bacteria that forms part of the normal gut flora in man and animals but is also widely distributed in the environment. Therefore when found in foods it is usually as a result of poor food handling practices and inadequate cleaning of equipment and work surfaces. It is commonly found in salad/vegetable products.
To reduce the risk of these organisms contaminating food it is important that raw and cooked foods are stored separately and good personal hygiene is maintained. Also ensuring good hygienic practices are maintained including thorough cleaning of equipment and surfaces and that raw products such as salad and vegetables are thoroughly washed.
Environmental swabs
Environmental swabs are taken for two reasons.
- To assess the cleanliness of the food environment and to assess the effectiveness of cleaning.
- To identify the presence of any food poisoning / indicator organisms in the food environment.
If swabs taken for cleanliness are considered unsatisfactory, then you need to re-examine your cleaning regimes and assess whether they are adequate, whether you are using the correct dilution factors and whether you are cleaning all appropriate areas, especially hand and food contact surfaces. It is important that these are cleaned as dirty surfaces help promote cross contamination.
Swabs which are unsatisfactory for pathogens or indicator organisms, should be regarded with greater concern and immediate action should be taken to eliminate any possible sources of such contamination. It is essential that sources of cross contamination are eliminated and that thorough cleaning is undertaken to eliminate the contamination.