title: HS-SPME-GC-MS/MS Method for the Rapid and Sensitive Quantitation of 2-Acetyl-1-pyrroline in Single Rice Kernels.
abstract: Demand for aromatic rice varieties (e.g., Basmati) is increasing in the US. Aromatic varieties typically have elevated levels of the aroma compound 2-acetyl-1-pyrroline (2AP). Due to its very low aroma threshold, analysis of 2AP provides a useful screening tool for rice breeders. Methods for 2AP analysis in rice should quantitate 2AP at or below sensory threshold level, avoid artifactual 2AP generation, and be able to analyze single rice kernels in cases where only small sample quantities are available (e.g., breeding trials). We combined headspace solid phase microextraction with gas chromatography tandem mass spectrometry (HS-SPME-GC-MS/MS) for analysis of 2AP, using an extraction temperature of 40 °C and a stable isotopologue as internal standard. 2AP calibrations were linear between the concentrations of 53 and 5380 pg/g, with detection limits below the sensory threshold of 2AP. Forty-eight aromatic and nonaromatic, milled rice samples from three harvest years were screened with the method for their 2AP content, and overall reproducibility, observed for all samples, ranged from 5% for experimental aromatic lines to 33% for nonaromatic lines.
authors.affiliation: Department of Viticulture & Enology, University of California, Davis , Davis, California 95616, United States.|Food Safety & Measurement Facility, University of California, Davis , Davis, California 95616, United States.
authors.forename: Helene
authors.initials: H
authors.lastname: Hopfer
authors.affiliation: Rice Experiment Station, California Cooperative Rice Research Foundation , Biggs, California 95917, United States.
authors.forename: Farman
authors.initials: F
authors.lastname: Jodari
authors.affiliation: Department of Plant Sciences, University of California, Davis , Davis, California 95616, United States.
authors.forename: Florence
authors.initials: F
authors.lastname: Negre-Zakharov
authors.affiliation: Agilent Technologies, Inc. , Wilmington, Delaware 19808, United States.
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Wylie
authors.affiliation: Department of Viticulture & Enology, University of California, Davis , Davis, California 95616, United States.|Food Safety & Measurement Facility, University of California, Davis , Davis, California 95616, United States.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Ebeler
mesh_terms: D005421:Flavoring Agents / Q000032:analysis* / Q000302:isolation & purification*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012275:Oryza / Q000737:chemistry*; D011758:Pyrroles / Q000032:analysis* / Q000302:isolation & purification*; D012639:Seeds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D005421:Flavoring Agents; D011758:Pyrroles; C426303:2-acetyl-1-pyrroline
keywords: 2-acetyl-1-pyrroline; GC-MS/MS; HS-SPME; aromatic rice