« Previous AbstractGenetic analysis of default mating behavior in Saccharomyces cerevisiae    Next AbstractHow to improve reliability in groundwater analysis: over a decade of experience with external quality control in field campaigns on volatile halogenated compounds »

Anal Chem

Title:		Laser mass spectrometry as on-line sensor for industrial process analysis: process control of coffee roasting
Author(s):		Dorfner R; Ferge T; Yeretzian C; Kettrup A; Zimmermann R;
Address:		"Institute of Ecological Chemistry, GSF-National Research Center for Environment and Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany"
Journal Title:		Anal Chem
Year:		2004
Volume:		76
Issue:		5
Page Number:		1386 - 1402
DOI:		10.1021/ac034758n
ISSN/ISBN:		0003-2700 (Print) 0003-2700 (Linking)
Abstract:		"The objective of the project is to develop on-line, real-time, and noninvasive process control tools of coffee roasting that help deliver a consistent and high-quality coffee aroma. The coffee roasting process was analyzed by direct injection of the roaster gas into a time-of-flight mass spectrometer and ionized either by resonance enhanced multiphoton ionization (REMPI) at 266 and 248 nm or vacuum ultraviolet single-photon ionization (VUV-SPI) at 118 nm. The VUV ionization scheme allows detecting mainly the most volatile and abundant compounds of molecular mass below 100 m/z, while REMPI ionizes mainly aromatic compounds of molecular mass larger than 100 m/z. Combining the compounds ionized by resonant and single-photon ionization, approximately 30 volatile organic compounds are monitored in real time. Time-intensity profiles of 10 important volatile coffee compounds were discussed in connection with their formation chemistry during roasting. Applying multivariate statistics (principle component analysis) on time-intensity traces of nine volatile coffee compounds, the roasting degree could be traced as a consistent path in the score plot of the two most significant principle components (including 68% of the total variance), for a range of roasting temperatures (200-250 degrees C)"
Keywords:		Beverages/standards Coffee/*chemistry Cooking/*standards Food Analysis/instrumentation/*methods Hot Temperature *Lasers Mass Spectrometry/*methods Molecular Weight Principal Component Analysis Quality Control Steel Temperature Time Factors;
Notes:		"MedlineDorfner, Ralph Ferge, Thomas Yeretzian, Chahan Kettrup, Antonius Zimmermann, Ralf eng Research Support, Non-U.S. Gov't 2004/02/28 Anal Chem. 2004 Mar 1; 76(5):1386-402. doi: 10.1021/ac034758n"