Key odorant · the claim says “primary odorants of wheat bread crust”
A review of bread aroma chemistry reports 2-acetyl-1-pyrroline, (E)-2-nonenal, 3-methylbutanal, 2,3-butanedione, methional and (Z)-2-nonenal as primary odorants of wheat bread crust, with 2-acetyl-1-pyrroline suggested as the key crust odorant behind its cracker-like note; the crumb has a different set, and these odorants are generated mainly during baking.
Scope: Wheat bread; crust and crumb differ, and odorants depend on ingredients, fermentation and baking. CLM-BREAD-001 ↗
Key odorant · the claim says “well-established contributor to the characteristic aroma”
Cooked rice contains many volatile compounds, while 2-acetyl-1-pyrroline is a well-established contributor to the characteristic aroma of aromatic rice.
Scope: Supports aroma complexity and the role of 2-acetyl-1-pyrroline in aromatic rice; not every rice variety has the same sensory profile. CLM-RICE-001 ↗
Checked against PubChem and Wikidata on 2026-10-02 (identifier check run 37063263965). Every name SmellBook uses must resolve to the same single PubChem compound.
WHAT THIS MEANS
SmellBook lists a molecule only where a VERIFIED claim names it, in the role and scope that claim states. A molecule reported in a smell's evidence is not the whole smell: most smells come from many compounds together, and the studies measured particular samples, such as one cultivar, an essential oil or a cooked product.