title: Volatile profiling of high quality hazelnuts (Corylus avellana L.): chemical indices of roasting.
abstract: The study proposes an investigation strategy to identify sensitive, robust and reliable chemical markers of hazelnut roasting. A fully-automated and validated analytical method, based on Headspace Solid Phase Microextraction (HS-SPME) coupled with Gas Chromatography-Mass Spectrometric detection (GC-MS), for effective off-line monitoring of changes in the volatile profile of high-quality hazelnuts was developed. Samples from two different harvests were submitted to roasting, following different time/temperature protocols and different technologies, enabling chemical changes to be correlated with technological processing and sensory quality. Chemical indices, expressed as analyte response ratio, were defined and their trend observed across roasting profiles. Reliability and robustness of chemical indices were also evaluated, in view of their application to on-line monitoring with Mass Spectrometry-based electronic nose technology (MS-nose). Experiments, simulating on-line chemical characterisation of the volatile fraction, were performed through a fully-automated system. The results confirmed: (a) the effectiveness of single process indicators of roasting selected by the separative method (5-methylfurfural, 1(H)-pyrrole, furfuryl alcohol, 1(H)-pyrrole-2-carboxaldehyde, 1-hydroxy-2-propanone, dihydro-2(3H)-furanone, 5-methyl-(E)-2-hepten-4-one, acetic acid, pyridine, furfural, pyrazine, and several alkyl-pyrazines); and, (b) the reliability of proposed chemical indices: 5-methylfurfural/2,5-dimethylpyrazine, 5-methylfurfural/2-methylpyrazine, 2,5-dimethylpyrazine/2,3-dimethylpyrazine; these maintained a consistent trend versus harvest and sampling/analysis technology.
authors: Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Via P. Giuria 9, I-10125 Torino, Italy.
authors: Luca
authors: L
authors: Nicolotti
authors: Chiara
authors: C
authors: Cordero
authors: Carlo
authors: C
authors: Bicchi
authors: Patrizia
authors: P
authors: Rubiolo
authors: Barbara
authors: B
authors: Sgorbini
authors: Erica
authors: E
authors: Liberto
mesh_terms: D003296:Cooking; D031211:Corylus / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D009754:Nuts / Q000737:chemistry*; D052617:Solid Phase Microextraction; D055549:Volatile Organic Compounds / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D055549:Volatile Organic Compounds