Bioactive compounds from hemp (<i>Cannabis sativa</i> L.) seeds: optimization of phenolic antioxidant extraction using simplex lattice mixture design and HPLC-DAD/ESI-MS² analysis

The extraction of phenolic compounds from defatted hempseeds was optimized using a simplex lattice
mixture design with three solvents (water, methanol, and acetone). The response variables were total
phenolic content (TPC) and antioxidant activity evaluated by different spectrophotometric tests. The results
showed that the binary acetone-water mixture in equal proportions is the optimal combination to achieve
the maximum TPC (53.65 mg GAE per g extract) with higher antioxidant activities (265.53, 36.25, 119.03,
69.46, and 68.91 mg TE g 1 extract for the TAC, DPPH, ABTS, FRAP, and CUPRAC tests respectively). In
addition, the phenolic profile analysis of defatted hemp seeds by HPLC-DAD/ESI-MS2 techniques showed
the predominance of hydroxycinnamic acid amides and lignanamides. It allowed visualizing the effect of
each solvent mixture on the relative extracted amount of each identified phenolic compound. This study
suggests that N-trans-caffeoyltyramine, cannabisin A, and cannabisin B might contribute strongly to the
potent antioxidant activity of hempseed extracts. Thus, it encourages the use of defatted hemp seeds as
a source of antioxidants with added value for pharmaceutical and cosmetic applications.