Essential oil and antioxidant activity of green mate and mate tea (Ilex paraguariensis) infusions

The soluble solids content, total phenolic content (Folin–Ciocalteau method), antioxidant activity (ferric thiocyanate method) and essential oil composition of green mate and mate tea (roasted green mate) infusions were analysed. The essential oil was obtained by hydrodistillation, and the volatile compounds were separated by high resolution gas chromatography and identified by mass spectrum and Kovats index. Although the antioxidant activity of green mate and mate tea infusions were equivalent, the soluble solids content in green mate was higher (4.2%) than in mate tea infusions (3.2%). Important compounds that add flavor to plant infusions—such as linalool, present in high concentrations in the green mate essential oil—were oxidized into linalool oxides after roasting. Limonene decreased from 19.5% to 7.3%, and furfural and methylfurfural were formed.