Comparison of Amomum tsaoko crevost et Lemaire from four regions via headspace solid-phase microextraction: Variable optimization and volatile characterization

Abstract

A novel headspace solid-phase microextraction method combined with gas chromatography–mass spectrometry was developed to extract volatiles from fresh Amomum tsaoko (FAT) from four districts. The single-factor experiment found an optimum extraction fiber (2 cm) coating with 50/30-μm divinylbenzene-carbon-polydimethylsiloxane, and the response surface design experiment determined that optimal extraction was achieved with equilibration and extraction times of 31 and 32 min at 42°C, respectively. Fifty compounds were identified in FATs from four regions, of which the main volatiles, including ( E )-2-octenal, ( E )-2-decenal, 2-isopropylbenzaldehyde, neral, geranial, and eucalyptol, accounted for a large proportion. Additionally, of the 50 compounds, 32 volatiles determined by orthogonal partial least squares-discriminant analysis contributed to the differentiation of FATs from the four distinct regions. Hierarchical clustering analysis revealed that four FATs were divided into three groups based on the volatiles identified. The four FATs had similar odor profiles, but the odor intensity of the Kongdang sample was weaker than that of the other samples. Therefore, this study not only developed a feasible method to extract volatiles from FAT but also established a theoretical basis for differentiating FATs from different regions. • Important variables of HS-SPME were optimized, and maximum extraction efficiency was achieved. • Fifty volatiles were identified in fresh Amomum tsaoko (FATs) from four regions. • OPLS-DA and HCA were used to differentiate FATs for the first time. • Odor profiles of four FATs were clarified.