title: Arabica and robusta coffees: identification of major polar compounds and quantification of blends by direct-infusion electrospray ionization-mass spectrometry.
abstract: Considering that illegal admixture of robusta coffee into high-quality arabica coffee is an important task in coffee analysis, we evaluated the use of direct-infusion electrospray ionization-mass spectrometry (ESI-MS) data combined with the partial least-squares (PLS) multivariate calibration technique as a fast way to detect and quantify arabica coffee adulterations by robusta coffee. A total of 16 PLS models were built using ESI± quadrupole time-of-flight (QTOF) and ESI± Fourier transform ion cyclotron resonance (FT-ICR) MS data from hot aqueous extracts of certified coffee samples. The model using the 30 more abundant ions detected by ES+ FT-ICR MS produced the most accurate coffee blend percentage prediction, and thus, it was later successfully employed to predict the blend composition of commercial robusta and arabica coffee. In addition, ESI± FT-ICR MS analysis allowed for the identification of 22 compounds in the arabica coffee and 20 compounds in the robusta coffee, mostly phenolics.
authors.affiliation: Aroma Analysis Laboratory, Institute of Chemistry, Federal University of Rio de Janeiro, 21945-970 Rio de Janeiro, Rio de Janeiro-RJ, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Garrett
authors.forename: Boniek G
authors.initials: BG
authors.lastname: Vaz
authors.forename: Ana Maria C
authors.initials: AM
authors.lastname: Hovell
authors.forename: Marcos N
authors.initials: MN
authors.lastname: Eberlin
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Rezende
mesh_terms: D040503:Coffea / Q000737:chemistry; D003069:Coffee / Q000737:chemistry* / Q000145:classification*; D005506:Food Contamination / Q000032:analysis*; D005583:Fourier Analysis; D016018:Least-Squares Analysis; D010636:Phenols / Q000032:analysis; D012639:Seeds / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D003069:Coffee; D010636:Phenols