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J Sep Sci

Title:		Development of a GC x GC-TOFMS method using SPME to determine volatile compounds in cacao beans
Author(s):		Humston EM; Zhang Y; Brabeck GF; McShea A; Synovec RE;
Address:		"Department of Chemistry, University of Washington, Seattle, WA 98195, USA"
Journal Title:		J Sep Sci
Year:		2009
Volume:		32
Issue:		13
Page Number:		2289 - 2295
DOI:		10.1002/jssc.200900143
ISSN/ISBN:		1615-9314 (Electronic) 1615-9306 (Linking)
Abstract:		"A method to analyze volatile compounds from cacao beans has been developed and evaluated. The method utilizes solid phase micro extraction (SPME) sampling followed by comprehensive 2-D (GC x GC) coupled with TOFMS. For the SPME procedure, a polydimethyl siloxane/divinyl benzene (PDMS/DVB) fiber was implemented. Cacao beans from four geographical origins were studied under two storage conditions, either dry or high moisture. A given cacao bean sample was sealed in a SPME vial and heated for 15 min. Extraction temperatures of 45, 60, 80, and 100 degrees C were analyzed and an optimal extraction temperature of 60 degrees C was determined. Many peaks were found to change as a function of storage conditions with Fisher Ratio analysis. Four representative compounds were identified and quantified (on a relative basis): acetic acid, nonanal, tetramethyl pyrazine, and trimethyl pyrazine. Acetic acid and nonanal were elevated in samples without evident mold on the bean surface, while the two pyrazines were elevated when mold was evident on the bean surface. The results for these comparisons, indicate that metabolism at the bean surface plays a role in the concentration of analytes, and can be readily determined using this analytical technology and methodology"
Keywords:		"Cacao/*chemistry Chromatography, Gas/instrumentation/*methods Food Preservation Humidity Mass Spectrometry/instrumentation/*methods Plant Extracts/*analysis Solid Phase Extraction/instrumentation/*methods Solvents/chemistry Volatile Organic Compounds/*ana;"
Notes:		"MedlineHumston, Elizabeth M Zhang, Yan Brabeck, Gregory F McShea, Andrew Synovec, Robert E eng Evaluation Study Germany 2009/07/02 J Sep Sci. 2009 Jul; 32(13):2289-95. doi: 10.1002/jssc.200900143"