Phenolic compounds from yerba mate based beverages--A multivariate optimisation.

This work used a central composite design to optimise a reverse phase high performance liquid chromatographic method for the simultaneous separation of gallic, syringic, 5-caffeoylquinic, caffeic, p-coumaric, ferulic, 3,4-dicaffeoylquinic, 3,5-dicaffeoylquinic, 4,5-dicaffeoylquinc acids, rutin in aqueous extracts of yerba mate (Ilex paraguariensis). The effect of the linear gradient time, the initial and the final methanol concentration in the mobile phase on the peak resolution and peak symmetry was evaluated. The 26 responses obtained were simultaneously optimised using the desirability method of Derringer and Suich. According to results, the increasing in the resolution and peak symmetry was achieved by using lesser levels of methanol in both initial and final gradient elution (-1.68, -1), as well as higher gradient times (+1, +1.68). The optimal condition (13.9-40% of methanol in 39.4 min) were successfully applied for analysis of chimarrão, tererê and mate tea aqueous extracts, which showed as excellent sources of chlorogenic acids.