What’s really in your lingonberry supplement?

Lingonberries are packed with phytochemicals, and extracts are sold as food supplements promising a wide range of health benefits – and often premium pricing particularly, for wild berry products.

Lingonberries – or Vaccinium vitis-idaea - tend to be much more expensive to source than other berries in the same family, and that creates the temptation to add these cheaper alternatives, dilute the final product, and hike profit margins.

Cranberries (Vaccinium macrocarpon), blueberries (Vaccinium corymbosum) and bilberries (Vaccinium myrtillus) are have all been encountered as adulterants in pure lingonberry products, but their similarity can make the substitution hard to spot.

Now, researchers from the Czech Republic – a major source country for wild lingonberries -  have developed what they think could be a simple way to tell if cranberries have been added to lingonberries, even if the proportion is as little as 1 per cent.

Writing in the journal Food Chemistry, the team from the University of Chemistry and Technology in Prague and the Research and Breeding Institute of Pomology Holovousy report a technique that uses the profile of  metabolites in frozen and dried samples of lingonberries and cranberries to distinguish between the species.

Using ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (U-HPLC-HRMS), the researchers identified specific marker compounds that could be used to tell if a sample was lingonberry, cranberry or a mixture, even if the sample was in extract form. The most significant markers identified were glycerophospholipid and polyphenol compounds.

“The knowledge obtained in this study can be used for checking compliance with label declaration both in case of various berries based food products and/or food supplements and prevent fraudulent practices, such as substitution or dilution which are quite common in case of high value commodities such as lingonberries,” they conclude.

In 2016, a sampling study by the US Department of Agriculture (USDA) gave a telling assessment of the level of mislabelling in dietary supplements claiming to made from Vaccinium berries, not necessarily just lingonberries.

By examining the anthocyanin profiles of the products, researcher Jungmin Lee determined that more than a third (14 out of 45 samples) did not contain the fruit listed as ingredients, and six of them contained no anthocyanins at all.

Five others had contents differing from labelled fruit (for example bilberry capsules containing Andean blueberry fruit), says the study in Food Science and Nutrition.

Image: skeeze / Pixabay