Evaluation of the carotenoid and fat-soluble vitamin profile of industrial hemp inflorescence by liquid chromatography coupled to mass spectrometry and photodiode-array detection

Industrial hemp (Cannabis sativa L.) is a plant matrix whose use is recently spreading for pharmaceutical and nutraceutical purposes. Detailed characterization of hemp composition is needed for future research that further exploits the beneficial effects of hemp compounds on human health. Among minor constituents, carotenoids and fat-soluble vitamins have largely been neglected to date despite carrying out several biological activities and regulatory functions. In the present paper, 22 target carotenoids and fat-soluble vitamins were analyzed in the inflorescences of seven Italian industrial hemp varieties cultivated outdoor. The analytes were extracted by cold saponification to avoid artifacts and analyzed by high-performance liquid chromatography coupled with Selected reaction monitoring mass spectrometry. Phytoene, phytofluene, and all-trans-β-carotene were the most abundant in all analyzed samples (31-55 µg g^-1, 11.6-29 µg g^-1, and 7.3-53 µg g^-1, respectively). Besides the target analytes, liquid chromatography coupled with photodiode-array detection allowed us to tentatively identify several other carotenoids based on their retention behavior and UV-vis spectra with the support of theoretical rules and data in the literature. To the best of our knowledge, this is the first comprehensive characterization of carotenoids and fat-soluble vitamins in industrial hemp inflorescence.