Variation in the aromatic nature of Nam-Hom coconut depends on the presence and contents of 2-acetyl-1-pyrroline

Using a non-heated solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) method, the impact aroma compound, 2-acetyl-1-pyrroline (2AP), was confirmed to naturally occur in the water of the aromatic Thai coconut cv. Nam-Hom and not in the other cultivars studied. The fruit was also harvested at different stages of maturity and at monthly intervals over a year, and the water was analyzed. 2AP was first produced 5.5 months after fruit set and continued to accumulate until physiological maturity at 11 months. The content varied with the season, being high in the dry period and low in the rainy period. This variation in 2AP concentration during the course of the year was in good agreement with changes in the aroma and sweetness of the coconut water.