Quality assessment of Cranberry (Vaccinium macrocarpon) based food supplements: HPTLC, HPLC and PAC quantification as effective tools for quality management

Cranberry-based food supplements with extracts from the fruits of Vaccinium macrocarpon are widely marketed for urinary tract health. As food supplements containing plant extracts, the so-called botanicals, are known to have quality problems the present study assembled efficient analytical protocols for evaluation of cranberry products for unambiguous identity testing and quantitation of procyanidins. Twelve cranberry-containing food supplements available in the D-A-CH region were included into the study. The analytical investigation comprised uniformity of mass testing of single-dosed capsule preparations, identity fingerprinting by HPTLC and HPLC and photometric quantification of the procyanidin content. Major deficiencies were detected such as labelling inconsistencies and deviations in capsule mass which indicated poor manufacturing control. The chromatographic analysis revealed that three products did not show specific anthocyanin fingerprints being typical for V. macrocarpon . In addition, deficiency was obvious concerning batch-to-batch conformity of certain brands. The results highlight the urgent need for specific analytical methods in quality control to verify botanical authenticity. Results again underscore critical regulatory gaps between the pharmaceutical-like presentation of such food supplements and their actual quality. Harmonized quality standards and stricter regulatory oversights are urgently needed to ensure transparency, consumer safety, and product integrity in the botanical supplement market.