Table of Contents
International Journal of Spectroscopy
Volume 2011, Article ID 815304, 5 pages
http://dx.doi.org/10.1155/2011/815304
Research Article

Difference Spectroscopy in the Analysis of the Effects of Coffee Cherry Processing Variables on the Flavor of Brewed Coffee

1Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA
2Batdorf & Bronson Coffee Roasters, 200 Market Street NE, Olympia, WA 98501, USA

Received 30 November 2010; Revised 14 February 2011; Accepted 22 March 2011

Academic Editor: A.M. Brouwer

Copyright © 2011 Donald J. Lyman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Infrared difference spectroscopy was used to study how changes in the processing of Arabica coffee cherries into green beans affected the flavor of coffee brewed from roasted green beans. Paired samples of green beans, in which the drying step or fermentation/washing step in their processing was altered, were roasted and brewed in a standard manner and their ATR-FT-IR spectra obtained. Difference spectra of the 1800 to 1680 cm−1 carbonyl region of water-subtracted spectra of paired samples of these brewed coffees provided data which indicated differences in brewed coffee flavor due to changes in fermentation/washing steps and drying steps involved in the processing of coffee cherries. The role of acid, ketone, aldehyde, ester, lactone, and vinyl ester carbonyl components on the flavor of brewed coffee is proposed that is consistent with the flavors as perceived by the coffee tasters.