Detection of adulterated coffee by fourier-transform infrared (FTIR) spectroscopy associated with sensory analysis




Because of its huge economic value, coffee has been the target of adulteration worldwide. Given the successful application of spectroscopic methods in detecting adulterants, this study aimed to employ attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) to detect adulterants in roasted coffee samples and compare the results with that of sensory analysis. In this study, twelve coffee samples were intentionally adulterated with varying concentrations, i.e., 10%, 30%, and 50%, of corn, beans, sawdust, and coffee husk. These adulterated samples were compared with one unadulterated coffee sample and four roasted and ground commercially available coffee samples; spectral readings of caffeine and chlorogenic acid (CGA) standards were performed for reference. The sensory analysis was performed by 17 tasters who were trained by a Q-grader. The infrared (IR) spectra 
(FTIR) data were processed by multiplicative signal correction (MSC) and subjected to a principal component analysis (PCA), along with the results of the sensory analysis. The combination of sensory analysis and IR spectrum allowed to differentiate samples of adulterated coffee and unadulterated coffee by PCA, with an explanation of 79% variance. The results demonstrated that the wavenumbers associated with CGA and caffeine contribute significantly in distinguishing adulterated coffee samples.
Key words: Adulterants; coffee quality; chemometric; sensory analysis.

Author Biography

Nelson Gutierrez Guzmán, Universidad Surcolombiana - Cesurcafe. Neiva, Colombia.

Postdoctorado Universidad Politecnica de Valencia
Tecnología de Alimentos
Febrerode2012 - Juniode 2012
Analisis y control de calidad en pescado

Doctorado Universidad Politecnica de Valencia
Doctorado tecnologia de alimentos
Enerode2002 - Noviembrede 2008
Identificación y priorización de factores críticos para implantar buenas prácticas agrícolas en productores de café y frutas en el departamento del Huila en Colombia

Maestría/Magister Universidad Politecnica de Valencia
Master ciencia ingenieria de alimentos
Enerode2002 - de 2002

Pregrado/Universitario Universidad Surcolombiana
Ingenieria agricola
Enerode1985 - de 1991


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How to Cite

BARRIOS-RODRIGUEZ, Y. F.; DEVIA-RODRIGUEZ, Y. .; GUZMÁN, N. G. Detection of adulterated coffee by fourier-transform infrared (FTIR) spectroscopy associated with sensory analysis. Coffee Science - ISSN 1984-3909, [S. l.], v. 17, p. e171970, 2022. DOI: 10.25186/.v17i.1970. Disponível em: Acesso em: 8 dec. 2022.