Let's start from the beginning. In agribusiness, after every production (biscuit for example), all conveyors, equipment and utensils must be cleaned to remove dirt, food residues, and reduce microbial contamination to start the next production. This cleaning process is also applied to remove allergens from one production to another. Companies check that their equipment is clean using surface sampling. Like in CSI, operators take swabs (identical to cotton swabs) to check that there is no risk of bacteria or allergens. No fear, it is only to control because the company has already validated its cleaning method and has proven that it is effective in reducing all risks of contamination to acceptable levels.
These swabs are then either tested on site or sent to laboratories for analysis. However, in good practice, it is required to test the swabs within 24 hours after receipt. A real challenge for analytical laboratories and also for companies that must ensure that their swabs are sent and arrive the same day in the laboratory.
Using new swabs (r-Biopharm Inc.), the PARERA platform demonstrated that milk allergens and gluten could be detectable on swabs even after 7 days of storage. Several scenarios were tested (number of days, temperatures, presence of bacteria on the swabs). Finally the platform advises to keep the swabs in cold temperatures and to perform three samples per surface to ensure a good representativeness. The platform work and conclusion should be used to support the development of new rules of good practices that would be less time-sensitive for food companies and analytical laboratories.
Our results were presented at the last AOAC International conference and can be found in the PDF.