ABSTRACT

This study was aimed to investigate volatile compounds of white and brown teff grain samples using the hydro-distillation and its extract in dichloromethane and n-hexane by gas chromatography-mass spectrometry. The optimized time for the hydro-distillation of the white and brown teff grain samples was nine hours. The dominant volatile compounds identified in the white and brown teff grain samples of the dichloromethane extract corresponding to peak area proportion were furfural (29.9%, 38.1%) and 5-methyl-2-furancarboxaldehyde (15.1%, 23.8%), respectively. The relative amount of dominant volatile compounds determined in the white teff grain sample of the n-hexane extract were 10.2% and 7.27% for the 5-methyl-2-furancarboxaldehyde and 2-[(methylthio)methyl]furan, respectively, and 18.4%, 16.0%, 12.5% and 9.73%, for the furfural, 5-methyl-2-furancarboxaldehyde, 2-[(methylthio)methyl]furan and benzeneacetaldehyde, respectively, for the brown teff grain sample. This study revealed that dichloromethane was efficient to extract more volatile compounds in the white teff grain sample than in the brown teff grain sample, whereas n-hexane was efficient to extract almost equal number of volatiles in both white and brown teff samples. Besides, aldehydes were the major constituents of the white and brown teff grain samples in both dichloromethane and n-hexane extracts.

摘要

本研究的目的是通过气相色谱-质谱法研究白色和棕色画眉草颗粒样品的挥发性化合物，使用水蒸馏及其在二氯甲烷和正己烷中的提取物。白色和棕色画眉草颗粒样品的水蒸馏优化时间为 9 小时。在二氯甲烷提取物的白色和棕色画眉草籽粒样品中确定的主要挥发性化合物对应于峰面积比例分别是糠醛（29.9%、38.1%）和 5-甲基-2-呋喃甲醛（15.1%、23.8%）。在正己烷提取物的白画眉草颗粒样品中测定的主要挥发性化合物的相对含量分别为 10.2% 和 7.27%，其中 5-甲基-2-呋喃甲醛和 2-[(甲硫基) 甲基]呋喃分别为 18.4% %、16.0%、12.5% 和 9.73%，对于糠醛，5-甲基-2-呋喃甲醛、2-[(甲硫基)甲基]呋喃和苯乙醛，分别用于棕色画眉草颗粒样品。该研究表明，与棕色画眉草颗粒样品相比，二氯甲烷可有效提取白画眉草颗粒样品中更多的挥发性化合物，而正己烷可有效提取白色和棕色画眉草样品中几乎相同数量的挥发物。此外，醛是二氯甲烷和正己烷提取物中白色和棕色画眉草颗粒样品的主要成分。而正己烷可有效提取白色和棕色画眉草样品中几乎相同数量的挥发物。此外，醛是二氯甲烷和正己烷提取物中白色和棕色画眉草颗粒样品的主要成分。而正己烷可有效提取白色和棕色画眉草样品中几乎相同数量的挥发物。此外，醛是二氯甲烷和正己烷提取物中白色和棕色画眉草颗粒样品的主要成分。