Heat Effects from Far-Infrared Source towards Antioxidant Activity in <i>Aquilaria</i> <i>subintegra</i> Leaves

Aquilaria tree is known for its ability of producing high quality resin called agarwood or gaharu oil. The leaves of this tree were under utilized and it is also claimed to be useful for treating a certain diseases. This study was aimed to identify the present of antioxidant activities in Aquilaria subintegra leaves. In the meantime, the effect of drying temperature from far-infrared (FIR) sources on antioxidant activity of the plant leaves was studied. Leaves were dried at different temperatures (40 °C, 50 °C, 60 °C) by using a (FIR) dryer. DPPH method was used to identify the scavenging activity (IC 50 ) of the methanolic leaves extracts. The result showed that methanol extract of the sample dried at 50 °C exhibited the highest antioxidant activity (IC 50 of 619.89μg/ml). In the range of temperature studied, 50 °C is proposed to be an appropriate drying temperature when using FIR as the source of heating element. In conclusion, FIR helps in lowering the drying temperature of Aquilaria subintegra leaves that retain significant amount of antioxidant activities which could be beneficial for treating certain diseases as claimed by others.