There are companies that produce testing kits to test the level of gluten in ready prepared foods.

These tests are marketed for testing meals in restaurants and can detect a level of gluten of 20 parts per million or less. 

Reliability of these kits should always be considered, not because the kits do not do what they are reported to do, but because the user may not maintain control of the conditions needed for accurate testing. For example, testing a small sample of a certain meal will not necessarily represent the gluten content of the complete meal. It is also important to make sure that all gluten is extracted from a food before testing using the chemicals provided. It is therefore very important to follow the manufacturer's guidance on using the test kits.

More information about testing food and auditing requirements can be found over on our Food Businesses page.