Theoretical framework to evaluate antioxidant synergistic effects from the coextraction of marjoram, rosemary and parsley

Synergies between compounds in food ingredients have been commonly obtained by the mixing of extracts produced individually. A different approach, based on the coextraction of plants and a new theoretical framework to identify synergistic and antagonistic effects in the coextracts, has been proposed in this study for the first time. The Pressurized Liquid Extraction (PLE) of rosemary and marjoram with parsley at several plant ratios was carried out and the antioxidant activity (ABTS and cellular assays) and phenolic compounds of the extracts were evaluated. Synergistic effects on the antioxidant activity of the extracts were identified from all the plant combinations. The HPLC-PAD analysis of the samples did not show a relation between the concentration of the main phenolic compounds in the coextracts and the observed antioxidant synergistic effects. The proposed theoretical framework may be successfully used for the determination of synergies in the bioactivity of extracts obtained by coextraction.