Volatile profiling of high quality hazelnuts (Corylus avellana L.): Chemical indices of roasting
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- 作者：Luca Nicolotti ; Chiara Cordero ; chiara.cordero@unito.it ; Carlo Bicchi ; Patrizia Rubiolo ; Barbara Sgorbini ; Erica Liberto
- 关键词：Hazelnuts ; Corylus avellana L. ; Roasting ; Quality indices ; Key-aroma compounds ; HS-GC&ndash ; MS ; MS-nose ; On-line monitoring
- 刊名：Food Chemistry
- 出版年：2013
- 出版时间：1 June, 2013
- 年：2013
- 卷：138
- 期：2-3
- 页码：1723-1733
- 全文大小：1416 K
文摘
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.