Quality of cranberry-derived products: one HPTLC method for identification and detection of adulterants

In the past decade Cranberry (Vaccinium macrocarpon Aiton) products became one of the most popular herbal dietary supplements for treatment of urinary tract infections. This popularity has resulted in numerous cases of adulteration, particularly with low-cost sources of anthocyanins, flavonoids and proanthocyanidins [1].

The aim of this study was to establish an HPTLC method for identification of cranberry-derived ingredients and detection of different known adulterants, based on multiple derivatization steps and detection modes.

A new HPTLC method was developed. A SPE cartridge was used to remove sugars and increase the detectability of flavonoids, catechins and anthocyanins. The new method, featuring a different mobile phase, detection modes and 2-derivatization steps, was tested with 52 cranberry-derived ingredients. Seven known adulterants were included in the analysis: bilberry and blueberry fruits, hibiscus flower, grape seed and skin, peanut skin, and pine bark extracts. Most of the samples show a fingerprint similar to that of cranberry juice. Nine samples of both, pomace and fruit, show no zone due to anthocyanidins. The method was capable of distinguishing all adulterants. Two commercial extracts presented zones characteristic for peanut skin and bilberry fruit and lacked cranberry zones. Those adulterations were not detected by HPLC.

The use of multiple detection in the HPTLC method allows verifying the identity of cranberry ingredients and also the detection of several types of adulteration, without additional chromatography. The novel method was proposed to the US pharmacopoeia to be included as identification method of cranberry-derived ingredients.

• References

• 1 Brendler T, Gafner S. Adulteration of cranberry (Vaccinium macrocarpon). Botanical Adulterant Bulletin. (1–8.12.2017). www.botanicaladulterants.com; Accessed on 11/06/2019