Identification of odorous constituents of bamboo during thermal treatment

Abstract

In this study, the effects of heat treatment on the odor and odorous constituents of moso bamboo (Phyllostachys pubescens L.) were studied. The component changes after heat treatment were examined by chemical analysis. The volatile organic compounds (VOCs) and odorants were identified by gas chromatography–mass spectrometry/olfactometry (GC–MS/O). The results showed that the heat treatment affected both the chemical components and the odors of bamboo. For untreated sample, totally 23 kinds of key VOCs and 41 kinds of odorants were identified. After heat treatment, both the amounts and intensities of the VOCs and odorants had significant changes because of chemical reactions during heat treatment, such as the thermo-degradation of hemicelluloses and cross-linking of lignin. The components were concentrated between 10 and 33 min in GC-O, which was different from the concentration time in GC–MS. Most of the odors smelled badly to humans and described as cheese, fishy, leather, bug, fat, etc. Comparing with 180 °C treated sample, sample treated at 200 °C underwent severer thermo-degradation process, which generated many small molecular weight compounds, and contributed to more odorants.