Chemical composition and biological activities of whole and dehulled hemp (Cannabis sativa L.) seeds

This study aimed to determine a complete chemical composition of eight different varieties of whole hemp seeds and eight samples of commercial dehulled hemp seeds. We also evaluated the phenolic profiles and antioxidant, cytotoxic, and antimicrobial properties of hydromethanolic seed extracts. Whole hemp seeds contain much more fibre than dehulled hemp seeds, which contain more fat and protein. Sucrose and raffinose were the most abundant soluble sugars, and citric and oxalic acids were the most abundant organic acids. In the hydromethanolic hemp seed extracts, we detected the phenolic acids ferulic acid-hexoside and syringic acid. Whole hemp seed extracts exhibited better antioxidant activity than dehulled hemp seed extracts, especially in the TBARS assay. Cytotoxic activity against NCI-H460 cells was also observed. The dehulled hemp seed extracts displayed antibacterial activity, especially against Bacillus cereus, Listeria monocytogenes, and Enterococcus faecalis, and antifungal activity to a lesser extent.The authors are grateful to ALIMNOVA Research Group 95105 (Fundaci´on Sabor y Salud-UCM, ref. 317/2020), as well as to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/ 2020). J.I. Alonso-Esteban thanks his grant (2016/01 M) to the Rafael Folch Foundation. R.C. Calhelha and L. Barros thank the national funding by FCT, P.I., through the institutional scientific employment program-contract, and J. Pinela (CEECIND/01011/2018) through the individual scientific employment program-contract. To FEDER-Interreg Espa˜na-Portugal programme for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P. Also to the Ministry of Education, Science and Technological Development of Republic of Serbia (451-03-9/2021-14/ 200007).