Effect of light intensity and processing conditions on bioactive compounds in maté extracted from yerba mate (Ilex paraguariensis A. St.-Hil.)

•Light intensity had no effect on phenolics and shading condition raised caffeine.•220 °C is a cut off temperature for yerba mate roasting.•Phenolics were more preserved when roasting time was shorter.•There was a strong correlation between phenolics and antioxidant capacity. This is the first report investigating the effects of cultivation, growth under full sunlight (MSL) or shade (MS), and processing (drying, sapeco and roasting) on the composition and antioxidant potential of maté. Samples were roasted (180 °C, 200 °C, 220 °C or 240 °C) for a fixed time (10 min) or roasted (10, 20, 30 or 40 min) at a fixed temperature (200 °C). HPLC/UV/MS analysis and measures of total phenolic content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition and soybean oil oxidation) were used to analyse phytochemicals. There were significant differences (p