SUBCRITICAL WATER AS A TOOL FOR OBTAINING PHYTOCOMPOSITIONS OF METABOLITES WITH HIGH ANTIOXIDANT ACTIVITY FROM BUCKWHEAT HUSKS (FAGOPYRUM ESCULENTUM)

Secondary plant metabolite (SPM) extracts with high antioxidant activity (AOA) are increasingly attracting attention as biologically active additives. Green chemistry methods are increasingly being considered for their production. In the presented work, subcritical water medium (SBW) in the temperature range from 120 to 220 °C was used to obtain phytocompositions with high antioxidant activity from common buckwheat husk (BH) (Fagopyrum esculentum). The use of SBW medium for extraction processes allows not only to increase the extraction of SPM from the plant matrix, but also to achieve a change in the phytochemical profile of the obtained extracts, which will determine the AOA of the resulting compositions. It has been demonstrated that the AOA of phytocompositions obtained from buckwheat husk (Fagopyrum esculentum) depends on the extraction conditions and is determined by the polyphenolic profile of the BHE extracts determined by UV/Vis spectrophotometry. It has been shown that the content of polyphenolic compounds and the AOA of the extracts depend on the extraction conditions (temperature of SBW). It has been demonstrated that the extract obtained from BHE in the SBW medium at 220 °C demonstrates the maximum AOA (EC50 = 18.2 μg/ml) among the obtained extracts. The presented results demonstrate the prospects of using SBW for obtaining extracts from BHE with a high content of polyphenols for the development of pharmaceuticals and food additives with high AOA.