Laser Induced Breakdown Spectroscopy (LIBS) Coupled with Multivariate Chemometric Method for Characterization and Quality Control of Coffee

Abstract

Authentication of coffee is important for ensuring reasonable competition and as a means of   protecting consumers against deception of mislabeling. Due to this there is a demand to have a fast and reliable means of measurement allowing the characterization and discrimination of coffee samples. We believe that Laser Induced Breakdown Spectroscopy (LIBS) coupled with multivariate chemometric methods is a solution for inspecting quality and adulterations of coffee. In this work seven Ethiopian export quality coffee and their ten mixtures are analyzed by using LIBS technique. Using the most relevant emission signals attempt was made to discriminate the samples and their mixtures using Principal Component Analysis (PCA). Moreover by taking each sample with its mixtures at a time we have shown the discriminating power of PCA using LIBS spectra for the detection of adulteration. We have also shown that the spectral markers for discrimination of coffee samples are Mg and Ca lines.

Keywords: Coffee, spectral marker, multivariate chemometric methods, Laser Induced Breakdown Spectroscopy (LIBS)