Quality of food supplements – a never ending story of food fraud in our real world

Herbal food supplements (syn. botanicals, [ 1 ]) are widely consumed for their potential health benefits. However, quality of these products can vary due to differences in raw material sources, processing methods, and potential adulteration. Ensuring authenticity, purity and consistency of these products is essential for consumer safety and product efficacy. This study focuses on the development and validation of analytical methods for quality assessment of herbal food supplements. Analytical techniques were developed for extracts from Passiflora incarnata , Vaccinium macrocarpon , Silybum marianum , and Boswellia serrata . For passionflower, a UPLC method was validated to quantify flavone C-glycosides. A clear difference between registered drugs and food supplements was visible. Only one food supplement showed positive identity, while all others did not meet specifications. In contrast, all registered passion flower herbal drugs were of high quality. Similar, cranberry ( Vaccinium macrocarpon ) food supplements were analyzed using HPLC for anthocyan-fingerprinting and photometric methods to determine proanthocyanidin levels. Again, food fraud was obvious for some preparations. The data presented here clearly reveal again massive deficits in quality of food supplements, and intensified quality control and quality surveillance by authorities by use of unambiguous and validated methods must be demanded. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany