2acetyl1pyrroline

2-acetyl-1-pyrroline, commonly abbreviated as 2-AP, is an organic compound that provides a distinctive popcorn-like, roasted aroma in heated foods. It is a five-membered heterocyclic amide, a substituted pyrroline with an acetyl group at the 2-position. The molecular formula is C6H9NO, and its molar mass is approximately 111.1 g/mol. 2-AP is a volatile compound that contributes strongly to aroma even at very low concentrations.

Natural occurrence and significance are centered on its role as a major odor-active component in basmati and jasmine rice, where it helps define the characteristic rice fragrance. It is also found in other heated foods such as popcorn, bread crust, and roasted coffee, where it adds a toasty, roasted note that is characteristic of browning reactions.

Formation and biosynthesis in foods occur primarily through Maillard-type reactions during thermal processing, involving reducing sugars and amino acid–derived intermediates that lead to the formation of pyrroline precursors. In rice, cultivar, storage conditions, and cooking methods influence the amount of 2-AP produced, affecting overall aroma quality.

Analytical aspects rely on gas chromatography coupled with mass spectrometry (GC-MS) and sometimes GC-olfactometry to identify and quantify 2-AP in complex matrices. Its odor activity is high due to a very low odor threshold, making it a key aroma-active compound in many foods.

Uses and safety notes indicate that 2-AP is studied and sometimes synthesized for fragrance and flavor applications, though it occurs naturally in foods. It is typically regarded as an aroma compound rather than a direct food additive, and safety assessments are conducted within the regulatory framework for aroma materials.