Characterization of different hempseed fractions after dehulling and defatting: chemical composition and functional properties

Hemp is a highly sustainable crop that grows rapidly and can be cultivated in a variety of climates. Hempseeds either whole or dehulled are processed into hempseed oil, hempseed protein powder, and hempseed milk, among other food products. The by-products, such as hempseed cake, are also used in animal feed processing. The aim of this study was to examine the bioactive components and functional characteristics of whole hempseed (WHS), dehulled hempseed (DHS), defatted hempseed/hempseed cake (HSC), and hempseed oil. DHS and HSC exhibited reduced condensed tannins and saponins compared to WHS. The most important cannabinoid in hempseed, d9-THC, was highest in HSC (0.061 µg/mg), followed by WHS (0.37 µg/mg), and then DHS (0.25 µg/mg). UHPLC-ESI-QTOF-MS identified 45 compounds, predominantly polyphenols in hempseed. Moreover, GC–MS detected various unsaturated fatty acids in hempseed oil, mainly C-18. WHS demonstrated potent antioxidant properties, protecting C. elegans from glucose-induced reactive oxygen species. Hempseed oil exhibited weak scavenging potential against DPPH (26.39%) and ABTS (10.30%) and showed limited antimicrobial effects against growth of pathogenic bacteria. In vitro lipase inhibition values were highest in WHS (83.63%), followed by DHS (52.94%) and HSC (43.08%). Dehulled and defatted hempseed had alpha-glucosidase inhibition values of 67.55% and 51.49%, respectively, compared to WHS (82.18%). This study offers insights into hempseed's bioactive components and health properties, serving as a reference for understanding the impact of dehulling and defatting on industrial hempseed and its oil quality as emerging food materials.