Cereal Chem. 70:381-384   |  VIEW ARTICLE

Comparison of Aroma Compound (2-Acetyl-1-Pyrroline) in Leaves from Pandan (Pandanus amaryllifolius) and Thai Fragrant Rice (Khao Dawk Mali-105).

V. Laksanalamai and S. Ilangantileke. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

A study was made to identify the aromatic compound 2-acetyl-1-pyrroline (AP) in fresh and aged (shelf- stored) Khao Dawk Mali (KDML) 105 (a well-accepted Thai aromatic rice variety), in nonaromatic rice, and in pandan (Pandanus amaryllifolius) leaves, using a steam distillation-extraction method. Gas chromatography-mass spectrometry identified a gas chromatographic peak for AP eluting at a retention time of 5.47 min. The compound from the volatile oil of pandan leaf was found to be similar to AP in molecular structure. Under the same gas chromatographic conditions used to identify the volatile oil of pandan leaf, the AP obtained from the volatile oil of fresh KDML-105 was found to have a clear separate peak that eluted at retention times between 5.43 and 5.59 min. The intensity of the AP was expressed as the ratio of the peak area of AP to the peak area of collidine (internal standard). The AP, however, was not found in nonaromatic rice and occurred in low concentrations in the aged KDML-105 rice. The study confirms the importance of AP as a key compound contributing to the pandanlike aroma in KDML-105 and indicates the need to determine measures to properly store the rice to ensure aroma stability.