Primary Odorants in Popcorn

Application of an aroma extract dilution analysis to freshly prepared popcorn revealed 23 odorants among which 2-acetyl-1-pyrroline (roasty, popcorn-like), (E,E)-2,4-decadienal (fatty), 2-furfurylthiol (coffee-like), and 4-vinyl-2-methoxyphenol (spicy) predominated with the highest FD factors (odor activities). Further potent flavor compounds showing roasty odors were 2-acetyltetrahydropyridine and 2-propionyl-1-pyrroline. the latter compound showed a very low odor threshold of 0.02 ng/L (air), which was in the same magnitude as that reported for the 2-acetyl-1-pyrroline homologue. Sensory analysis of homologues 2-butanoyl- and 2-hexanoyl-1-pyrroline revealed that a longer alkyl side chain canceled the roasty flavor note and increased the odor thresholds by a factor of 10⁵.