Jéssica de Cássia Tomasi
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Gabriel Goetten de Lima
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Ivar Wendling
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Cristiane Vieira Helm
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Fabrício Augusto Hansel
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Abstract
This work investigates the effect of different drying processes on chemical, nutritional and leaves colour characteristics for Ilex paraguariensis leaves. These processes were composed of typical drying techniques (roasting + rotary dryer and roasting + conveyor dryer), and cutting-edge techniques (microwave oven [MW], freeze-drying (FD) and oven dryer [OD]). The MW can be an alternative technique, this is because the content of phenolic compounds (77 mg/g), antioxidant capacity (DPPH and ABTS) (∼370 and ∼1040 μM TE/g), methylxanthines and caffeoylquinic acids (2–4 mg/g) were similar, and sometimes higher, to the conventional drying processes. Leaves dried with MW also exhibited satisfactory nutritional analysis for protein (16.4%), dietary fibre (52.3%), ash (6.4%), lipid (6.1%) and moisture (5.7%), implying that yerba mate is a potential source of fibre and protein. Furthermore, the MW preserved leaves green colour (high and low scores of b* and a*, respectively).