TY - JOUR
T1 - Discrimination of organic coffee via Fourier transform infrared-photoacoustic spectroscopy
AU - Gordillo-Delgado, Fernando
AU - Marín, Ernesto
AU - Cortés-Hernández, Diego Mauricio
AU - Mejía-Morales, Claudia
AU - García-Salcedo, Angela Janet
PY - 2012/8/30
Y1 - 2012/8/30
N2 - BACKGROUND: Procedures for the evaluation of the origin and quality of ground and roasted coffee are constantly needed for the associated industry due to complexity of the related market. Conventional Fourier transform infrared (FTIR) spectroscopy can be used for detecting changes in functional groups of compounds, such as coffee. However, dispersion, reflection and non-homogeneity of the sample matrix can cause problems resulting in low spectral quality. On the other hand, sample preparation frequently takes place in a destructive way. To overcome these difficulties, in this work a photoacoustic cell has been adapted as a detector in a FTIR spectrophotometer to perform a study of roasted and ground coffee from three varieties of Coffea arabica grown by organic and conventional methods. RESULTS: Comparison between spectra of coffee recorded by FTIR-photoacoustic spectrometry (PAS) and by FTIR spectrophotometry showed a better resolution of the former method, which, aided by principal components analysis, allowed the identification of some absorption bands that allow the discrimination between organic and conventional coffee. CONCLUSION: The results obtained provide information about the spectral behavior of coffee powder which can be useful for establishing discrimination criteria. It has been demonstrated that FTIR-PAS can be a useful experimental tool for the characterization of coffee.
AB - BACKGROUND: Procedures for the evaluation of the origin and quality of ground and roasted coffee are constantly needed for the associated industry due to complexity of the related market. Conventional Fourier transform infrared (FTIR) spectroscopy can be used for detecting changes in functional groups of compounds, such as coffee. However, dispersion, reflection and non-homogeneity of the sample matrix can cause problems resulting in low spectral quality. On the other hand, sample preparation frequently takes place in a destructive way. To overcome these difficulties, in this work a photoacoustic cell has been adapted as a detector in a FTIR spectrophotometer to perform a study of roasted and ground coffee from three varieties of Coffea arabica grown by organic and conventional methods. RESULTS: Comparison between spectra of coffee recorded by FTIR-photoacoustic spectrometry (PAS) and by FTIR spectrophotometry showed a better resolution of the former method, which, aided by principal components analysis, allowed the identification of some absorption bands that allow the discrimination between organic and conventional coffee. CONCLUSION: The results obtained provide information about the spectral behavior of coffee powder which can be useful for establishing discrimination criteria. It has been demonstrated that FTIR-PAS can be a useful experimental tool for the characterization of coffee.
KW - Chemical composition
KW - Discrimination criteria
KW - FTIR spectroscopy
KW - Organic coffee
KW - Photoacoustic
UR - http://www.scopus.com/inward/record.url?scp=84864013872&partnerID=8YFLogxK
U2 - 10.1002/jsfa.5628
DO - 10.1002/jsfa.5628
M3 - Artículo
SN - 0022-5142
VL - 92
SP - 2316
EP - 2319
JO - Journal of the Science of Food and Agriculture
JF - Journal of the Science of Food and Agriculture
IS - 11
ER -