Effect of Roasting Temperature on Volatile Components of Chicory Root Extract Analyzed by HS-SPME-GC-MS and Electronic Nose

Abstract

To investigate the effect of roasting temperature on the aroma quality of chicory root extract, headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with electronic nose technology was employed to analyze the differences in volatile aroma components of chicory root extract under different roasting temperature conditions. The key aroma components were identified by the relative odor activity value method (ROAV). Results showed that 104 volatile components were detected in the extracts at different roasting temperatures, including aldehydes (24), ketones (11), acids (14), alcohols (3), esters (22), hydrocarbons (11), phenols (7), and other compounds (12). As increase of roasting temperature, the relative content of acids decreased obviously, and the relative content of aldehydes and ketones increased. Chicory root samples roasted at 150 ℃ possessed the most varieties of volatile components, reaching 81, and the flavor richness was the highest. The analysis of the cluster heatmap showed that there were significant differences among volatile components of chicory root extracts at different roasting temperatures. Electronic nose technology could effectively distinguish the volatile aroma characteristics of chicory root extracts at different roasting temperatures. Totally 14 volatile components were identified as key aroma components with relative odor activity values (ROAV>1). Among them, phenylacetaldehyde and N-methylpyrrole-2-carboxaldehyde contributed the most to the overall aroma characteristics of the sample, giving the baked and nutty aroma. This study revealed the effects of different roasting temperatures on the volatile components, providing theoretical and experimental references for the development of the characteristic flavor ingredients of chicory and the improvement of flavor quality.

Keywords

• chicory root
• headspace solid phase microextraction-gas chromatography-mass spectrometry (hs-spme-gc-ms)
• e-nose
• volatile components
• relative odor activity value (roav)