Valorisation of olive pomace: phenolic prospecting and biological potential

Phenolic compounds were extracted from biphasic olive pomace and their biological potential was characterised. Two different extracts were prepared, E1 (40% methanol) and E2 (80% methanol), both subjected to agitation (180 min) and 70 °C. LC-ESI-qTOF-MS was used for individual quantification of the extracted phenolic compounds. The antioxidant activity was determined using different methods, including nitric oxide, DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radical. The enzymes α-amylase and α-glucosidase were used to evaluate the antihyperglycemic potential and sulforhodamine B and MTT (tetrazolium salt) for antitumor activity. To evaluate the antimicrobial activity, minimum inhibitory concentration and minimum bactericidal concentration of the extracts, the disc diffusion technique was used. Among the phenolic compounds present, tyrosol was highlighted in both extracts, as well as the anti-hyperglycemic effects, antitumor action and antioxidant activity. The antimicrobial activity found in the extracts was considered moderate to weak.