At Fera our experts can develop and carry out a standard microbiological testing method to assess the bacterial content of food and beverage products as well as feed products to determine their use by date as well as associated hygiene or product practices. Our methods are based on standard ISO method and consist of testing on growth plates and results are recorded and interpreted by a qualified microbiologist within an accredited laboratory setting.
Use by dates are determined during the development of any food product using scientific knowledge and testing. The length of time food is safe for is influenced greatly by the type of food, its recipe and the way that it’s packed. The main factors that can affect the speed of microbial growth, or the type of microorganisms able to grow, are temperature, water availability, pH and oxygen. Products with high levels of salt or sugar will have less available water for microorganisms to grow. Similarly, the addition of acidic ingredients, such as vinegar and fruit juice, will reduce the pH and also reduce microbial growth, thereby extending the food's shelf life. Some food packs have the oxygen removed, which can reduce microbial growth and make food stay fresher for longer. However, once such a pack is opened, oxygen returns and can limit the life of the food. Foods with a shelf life of at least two years are not required to display a best before date.
Given the complexity of the wide range of factors that contribute to a shelf life of food from the physical, microbiological and chemical processes as well as product characteristics, including the quality and consistency of ingredients, the moisture content and acidity levels, all play a part, as do external factors like storage, transport and packaging materials. Guidance on the application of date labels to food can be found here
Our method includes a pre-agreed screen of the product for the presence or absence of microorganisms as well as the amounts present over a pre-agreed time period. This time period could either be used to determine the shelf life of anew product or to confirm the shelf life in case of product re-formulation. Results are interpreted by a qualified microbiologist and are reported through in a PDF format which includes an interpretation of the results with regards to the product food safety. We offer a follow up service in which you can discuss your results and possibilities for further testing or services with a qualified microbiologist
Fera is the UK National Reference Laboratory for Materials and Articles in Contact with Food. Our staff are experts in policy and legislation in this area as well as in analysis of migrating substances from these materials or articles. Our expertise in this area focuses on research, surveillance and targeted and non-targeted analysis of known and unknown migrants in food contact materials and articles, foods and food simulants, providing solutions for the challenges faced in the complex food supply chain that exists.
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To order your shelf-life or stability analysis from Fera:
1. Download the price guide and decide on your desired test
2. Download the product order form and complete for each product you wish to be analysed
3. Send this product order form, along with the desired test, to Fera via
The use by date of a product is about safety of the product, after the date has passed the food manufacturer can no longer guarantee the microbiological safety of the product. This applies to very perishable products such as salads, meats or other ready to eat foods. Testing for the use by date means investigating the micro content from start to proposed end and making sure there aren’t any dangerous levels of organisms present before.
The best before date is about quality of the product and applies to foods which are generally very stable due to their storage conditions, for example frozen products or dried products. But some manufacturers still want their own best before dates they give checked as sometimes a change in production processes or packaging can affect it.
Fera's consultancy service is made up of senior scientists who have broad and deep experience in the food industry that we can bring to bear on your research project which goes beyond analysis and scientific expertise.
So if you have questions about shelf life or stability testing, legislation, or the regulatory environment please don't hesitate to get in touch.
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