By Allergen Bureau

Are lentils truly gluten free?

While lentils are naturally gluten-free, farming practices may cause lentils to come into contact with wheat, barley, or rye while being grown, harvested, or stored. After several consumer complaints about errant grain in whole, dry lentils, a 2021 survey has looked at a variety of brands of lentils to see how often gluten-containing grains are present.

In Australia and New Zealand, any product labelled as gluten free must meet the ‘nil detected’ regulatory criteria. Internationally, the Codex standard requires gluten free products to contain less than 20 parts per million of gluten. According to this requirement, a 500g bag of lentils could contain 1 intact gluten-containing grain and still be considered gluten free.

Twenty-five bags of different dry lentil products representing 24 brands were purchased online and at various grocery stores. Nine of the 25 products were labelled gluten-free. Of these, 1 was labelled certified gluten-free. Twelve of the 25 products contained an allergen advisory statement for wheat or gluten, including 3 products labelled gluten-free. Eighteen of 25 products contained a statement advising consumers to sort and rinse lentils, including 5 products labelled gluten-free.

Researchers hand sorted each bag of lentils individually. Two of the 25 packages of lentils contained errant gluten-containing grains. One bag contained a grain of wheat while another contained a grain of wheat and a grain of barley. While neither of the bags were labelled gluten free, both were 454g (16-ounce) and would therefore not meet the Codex ‘gluten free’ requirements.

Non-gluten-containing foreign material was found in 6 additional bags of lentils. This material included split peas, mallow seeds, stones, and rice grain.

The study authors suggest that manufacturers should consider sorting whole lentils for gluten-containing grain and testing lentil flour for gluten. Consumers concerned about the presence of gluten may want to choose lentils grown and processed following a gluten-free purity protocol.

Reference: Thompson et al. 2022. Frontiers in Nutrition. DOI: 10.3389/fnut.2022.867954

Available with Open Access.