Thermal characterization of Aspidosperma pyrifolium Mart. plant drugs

Aspidosperma pyrifolium Mart. is an endemic plant from Brazilian northeastern, which is widely used in folk medicine to treat dermatitis, gastritis, and malaria due to its anti-inflammatory activity. Thus, the aim of this work was to characterize by analytical techniques A. pyrifolium in different particle sizes to use in the production of tea. For characterization, thermal analysis, optical microscopy, and near-infrared spectroscopy (NIR) techniques were used. After sieving, five samples, named AP01 (> 355 μm), AP02 (≥ 180 μm), AP03 (≥ 155 μm), AP04 (≥ 75 μm), and AP05 (≥ 38 μm), were obtained. Thermogravimetry curves showed three steps of decomposition, with different percentages of mass loss. The second step of decomposition showed the highest mass loss for the five samples. DTA curves of five samples showed a first endothermic peak at 91.70, 96.22, 96.29, 91.09, and 86.32 °C for AP01, AP02, AP03, AP04, and AP05, respectively. Decomposition of all particles occurred from 200 °C. The activation energy obtained through kinetic models showed significant differences between the two methodologies employed. NIR spectra were treated using chemometric tools, including principal component analysis and two PC were necessary to properly separate the samples. The analytical techniques used in this study allowed us to properly characterize the powders and could be used in the production of tea.