Evaluation of the Lipid Composition of Commercially Available Evening Primrose Products by Gas Chromatography and Mass Spectrometry

Evening primrose oil supplements are rich in omega-6 fatty acids, with emphasis on linoleic and γ-linolenic acids, being taken in the treatment and prevention of diseases, but mainly for the relief of symptoms caused by premenstrual tension and menopause in women. This study aimed to evaluate the quality of the lipid profile of evening primrose oil supplements using gas chromatography techniques with a flame ionization detector and mass spectrometry with electrospray ionization. For this, eight commercially available national evening primrose oil brands were used. Of the eight samples analyzed, only two met all the standards established in legislation for fatty acids. The remaining capsules were subjected to triacylglycerol analysis and using a calibration curve the presence of soybean oil in the composition of the evening primrose oil capsules was verified. From the triacylglycerol with a mass/charge ratio of 901, it was possible to identify the addition of 31.16-85.88% of soybean oil in six of the eight capsules, leading the consumer to ingest products that did not comply with current legislation.