Solid-Phase Microextraction(SPME)을 이용한 둥굴레차의 증자 여부에 따른 향기성분 특성 비교

Comparison of Flavor Compounds in Steamed- and Nonsteamed-Roasted Polygonatum odoratum Roots by Solid-Phase Microextraction

고품질 둥굴레차의 제조를 위한 기반연구로서 solid-phase microextraction(SPME)을 이용한 headspace 방법에 의해 볶음 전 중자(steaming) 여부에 따른 둥굴레차의 향기성분 특성을 비교하였다. SPME fiber에 대한 향기성분의 흡착조건은 $60^{\circ}C$에서 30분이 적합하였고, 무중자 및 중자(120분)된 시료를 $130^{\circ}C$에서 15분간 볶음 처리하여 분석 GC chromatogram에서는 40여 종의 peak가 분리되었고, 전반적인 pattern은 유사하였으나 서로 상이한 peak특성이 관찰되었다. 분리된 성분들을 GC-MS와 retention time 비교에 의해 25종을 동정하였으며, 무중자 볶음처리 둥굴레는 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2,5-di-methyl-4-hydroxy-3(2H)-furanone, 2-acetyl-1-pyrroline 등의 pyrazine류 함량이 중자 후 볶음 둥굴레보다 높게 나타나 둥굴레의 고유한 향과 맛에 큰 영향을 미칠 것으로 추정되었다. 특히 중자 후 볶음 처리한 둥굴레의 경우에는 acetic acid(8.17%)와 hexanoic acid(5.43%)의 함량이 무중자 시료(2.40%와 2.00%)보다 높게 나타났다.

The headspace flavors of roasted tea, prepared with steamed and nonsteamed polygonatum roots, were absorbed in solid-phase microextraction(SPME) fiber coated with $65\;{\mu}m$ of carbowax/divinylbenzene(CW/DVB) and analysed by GC-MS. The absorption conditions of SPME fiber for equilibrated headspace were selected as $60^{\circ}C$ and 30 min. In a comparison for both samples roasted at $130^{\circ}C$ for 15 min, gas chromatograms showed a similar pattern in overall profiles between steamed and nonsteamed samples before roasting, but some differences were observed in peak characteristics. From 40 separated peaks, 25 compounds were identified with both GC-MS and retention time comparison. The pyrazines including 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, 2-acetyl-1-pyrroline, etc. were higher in their contents in nonsteamed-roasted sample than steamed-roasted one. In particular, steamed-roasted polygonatum showed higher contents of acetic acid(8.17%) and hexanoic acid(5.43%) than the corresponding compounds of nonsteamed-roasted one, 2.40% and 2.00%.