Mahatheeranont S, Keawsa-Ard S, Dumri K
Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
J Agric Food Chem. 2001 Feb;49(2):773-9. doi: 10.1021/jf000885y.
Volatile components of uncooked Khao Dawk Mali 105 brown rice were extracted using indirect steam distillation under reduced pressure and controlled temperature in order to prevent cooking. Analysis of the fresh extract by capillary gas chromatography-mass spectrometry revealed that there were >140 volatile constituents. Among these, 70 volatiles were identified, including 2-acetyl-1-pyrroline (2AP), a key aroma compound of cooked rice. Further study concentrated on an improved method for the quantification of 2AP in uncooked brown rice. The method was simplified by utilizing a solvent extraction procedure. Quantitative analysis was performed using a capillary gas chromatographic system employing a flame ionization detector with the aid of a more selective column, CP-Wax 51, for amines. This improved chromatographic system had remarkable detection sensitivity for 2AP in the rice extracts so that 2AP in an extract of only 0.5 g of uncooked Khao Dawk Mali 105 brown rice could be detected.
为防止蒸煮，采用间接减压蒸汽蒸馏法并控制温度，提取未煮过的泰国香米105糙米的挥发性成分。通过毛细管气相色谱 - 质谱联用仪对新鲜提取物进行分析，结果显示有超过140种挥发性成分。其中，鉴定出70种挥发性成分，包括2 - 乙酰基 - 1 - 吡咯啉（2AP），它是煮熟米饭的关键香气化合物。进一步的研究集中在改进未煮过的糙米中2AP的定量分析方法。该方法通过采用溶剂萃取程序得以简化。借助一根对胺类更具选择性的色谱柱CP - Wax 51，使用配备火焰离子化检测器的毛细管气相色谱系统进行定量分析。这种改进后的色谱系统对大米提取物中的2AP具有显著的检测灵敏度，以至于仅0.5克未煮过的泰国香米105糙米提取物中的2AP都能被检测到。
