Characterization of the odorous constituents and chemical structure of thermally modified rubberwood

Rubberwood is a sustainable timber from tropical plantations, and is widely used in human’s daily routine like furniture and interior decoration. The thermal modification technology can effectively make rubberwood preservative, and improve its dimensional stability, while the odorants emitted from thermally modified rubberwood limited its application and recently has attracted people’s attention. In this study, the effects of thermal modification on odor and key odorous constituents of rubberwood were studied. The volatile odorants were identified by sensory evaluation via gas chromatography–mass spectrometry/olfactometry. To gain profound insights into the contribution of single odorants to the overall odor of heat-treated rubberwood, the odor-active constituents were calculated using relative odor activity values (ROAV) on the basis of odor thresholds. It’s revealed that with increasing temperature, the ROAV of 5-methyl-2-furancarboxaldehyde increased from 0.01 to 2.6 and then decreased to 0.7, and 5-methyl-2-furancarboxaldehyde became the important odorant of thermally modified rubberwood ranged from 155°C to 185°C. The odor of 5-methyl-2-furancarboxaldehyde smelled like chocolate and burnt. The identification of odorants from thermally modified rubberwood could provide theoretical guidelines for further controlling the production technology to produce the low odor thermally modified rubberwood.