The ability of deep eutectic solvent systems to extract bioactive compounds from apple pomace

The objective of this study was to examine the bioactivity of extracts from apple pomace obtained by non-conventional green extraction methods (DES systems). Bioactivity was antioxidant capacity and ability to stimulate insulin secretion from pancreatic beta-cells. The antioxidant capacity of extracts was examined using the DPPH and the FRAP assay. Impact of the extracts on cell viability and insulin secretion were examined using the BRIN-BD11 cell line. ChCl:EG(1:4) extracts resulted in high antioxidant capacity in the DPPH assay (80.1% inhibition versus 11.3%). Extracts obtained from the classical systems demonstrated an ability to promote insulin secretion significantly higher than the positive control, p < 0.05. ChCl:EG(1:4) extracts stimulated insulin secretion to a lesser extent. Overall, the data provides evidence for the potential of DES systems to extract bioactive compounds from apple pomace that have relevance for metabolic health. Further optimisation of the extraction procedures should be tailored to the desired bioactive properties.