Scientists from the Higher Council for Scientific Research (CSIC) in Madrid, Spain developed a new approach based off various chromatographic techniques for evaluating the quality and authenticity of raspberry ketones, a type of chemical used in food supplements. Their findings were published in the Journal of Chromatography A (1).
A recent trend is the growing use of food supplements to increase the intake of certain nutrients and achieve certain physiological effects. Notably, this has become evident in the case of plant-based supplements, which are viewed as natural and safe alternatives to pharmaceutical products. Specifically, food supplements aimed at overweight control have become popular due to the widespread prevalence of obesity. One commonly marketed type of weight supplement is those that contain 4-(4-hydroxyphenyl)-butan-2-one (also known as raspberry ketone [RK]).
RK is a chemical found in red raspberries (Rubus idaeus L.) that is believed to increase metabolism, increase the body’s fat-burning pace, and reduce appetite. This chemical is typically used to treat obesity, hair loss, and other conditions (2). RK contains various bioactive properties, such as hepatic, cardiac, and gastric protection, while also holding potential benefits for conditions like Alzheimer’s. While these substances are popular, fraudulent practices, such as mislabeling or adulteration, are a concern for consumers. As such, there has been demand for comprehensive analytical approaches for ensuring the quality of these products.
In this study, a novel multi-analytical strategy was developed to detect potential composition frauds in RKSs. The approach combined gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–MS (LC–MS). GC–MS was used to analyze carbohydrate mixtures after conversion to volatile derivatives; meanwhile, LC–MS was used to determine raspberry phenolic compounds. This combination, according to the researchers, can provide comprehensive characterization of RKS composition aimed at better detecting frauds. Unlike previous approaches, which solely focus on RK content, the scientists also considered additional raspberry-specific compounds, in hopes of providing information on the type of fraud committed.
The optimized LC–MS method allowed for precise (RSD < 3 %) and sensitive (LOD 150ng mL−1) determination of RK and other phenolic compounds. Meanwhile, the developed GC–MS methodology provided efficient carbohydrate separation. Among supplements declaring RK content, 60% of the samples taken showed discrepancies between labeled and measured values, with most containing less concentrations than first expected. Multicomponent characterization of reference raspberry extracts allowed the proposal of myo-inositol and phenolic compounds (ellagic acid and epicatechin) as markers of natural origin.
With this system’s application to representative sets of commercial RKSs, the multicomponent strategy simultaneously allowed the identification of a number of supplements with questionable efficacy due to their extremely low contents of bioactive RK, frequent mislabelling practices due to discrepancies with the declared RK content, and the detection of supplements with high RK content of undeclared synthetic origin. These findings, therefore, may make this approach worthy of consideration by nutraceutical companies or by regulatory bodies that aim to assure food supplement quality and authenticity, the researchers wrote.
(1) Luque-Jurado, I.; Yesares, M.; Soria, A. C.; Sanz, M. L. Evaluation of Quality and Authenticity of Raspberry Ketone Supplements by a Multianalytical Approach. J. Chromatogr. A 2025, 1757, 466131. DOI:
(2) Raspberry Ketone – Uses, Side Effects, and More. WebMD 2025.
