Hemp seed-based food products as functional foods: A comprehensive characterization of secondary metabolites using liquid and gas chromatography methods

Abstract

Despite hemp has a long history as food, in the last years the interest in cannabis cultivars, including new varieties, requires a deeper investigation of hemp seed-based food products as a precious source of biomolecules. In the present work, a comprehensive characterization of the minor components occurring in hemp seed-based food products i.e. oil, flour and flour by-product, is reported. For this goal, volatile (i.e. terpenes, hydrocarbons, furans and ketones) and non-volatile (i.e. tocopherols, cannabinoids and phenolic compound) metabolites were investigated by means of different chromatographic techniques. HPLC in combination with PDA, fluorescence, and MS detection was employed to analyse non-volatile fraction. Furthermore, GC coupled with FID and MS detectors were used for the analysis of volatiles and unsaponifiable compounds, the latters after conversion into more volatile trimethylsylil derivatives. Terpenes represented the most abundant compounds among volatiles. A total of 58 compounds belonging to the unsaponifiable matter was identified only in hempseed oils. Among tocopherols, γ-tocopherol was quantified at the highest level. Phenols and cannabinoids were also investigated, and a total of 52 compounds were identified and quantified. To the best of our knowledge, this is the first study providing a thorough chemical characterization of minor fraction of hemp products.