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.