Quantitative Analysis on 2-Acetyl-1-pyrroline of an Aromatic Rice by Stable Isotope Dilution Method and Model Studies on its Formation during Cooking

A quantitative analysis of 2-acetyl-1-pyrroline from aromatic rice samples using a stable isotope dilution method was developed. The compound was extracted from seedlings, roots, and husks at room temperature for 2 h, whereas milled or brown rice samples were extracted at 75 °C. The recovery of 2-acetyl- 1-pyrroline was linear from 5 to 5000 ng/g with sensitivity of less than 0.1 ng/g. 2-Acetyl-1-pyrroline showed tautomerism with animide form. The results revealed that 2-acetyl-1-pyrroline present in aromatic rice samples did not form during cooking or postharvest processes.