Classification of Coffee Beans by GC-C-IRMS, GC-MS, and¹H-NMR

Abstract

In a previous work using 1H-NMR we reported encouraging steps towards the construction of a robust expert system for the discrimination of coffees from Colombia versus nearby countries (Brazil and Peru), to assist the recent protected geographical indication granted to Colombian coffee in 2007. This system relies on fingerprints acquired on a 400 MHz magnet and is thus well suited for small scale random screening of samples obtained at resellers or coffee shops. However, this approach cannot easily be implemented at harbour's installations, due to the elevated operational costs of cryogenic magnets. This limitation implies shipping the samples to the NMR laboratory, making the overall approach slower and thereby more expensive and less attractive for large scale screening at harbours. In this work, we report on our attempt to obtain comparable classification results using alternative techniques that have been reported promising as an alternative to NMR: GC-MS and GC-C-IRMS. Although statistically significant information could be obtained by all three methods, the results show that the quality of the classifiers depends mainly on the number of variables included in the analysis; hence NMR provides an advantage since more molecules are detected to obtain a model with better predictions.

Metabolomics as a marketing tool for geographical indication products: a literature review

“…Analytical, spectrometric, and computational techniques used in metabolomic studies enable the identification of particular characteristics and nuances of metabolites of plants belonging to the same species, revealing the consequences of region-specific natural resources and human processes involved in the cultivation system. A great variety of agricultural products and foodstuff have already been investigated using metabolomics, such as olive oils [ 46 ], wines [ 64 ], coffee [ 5 ], cheeses [ 91 ], hops [ 72 ], nuts [ 13 ], and vinegars [ 104 ]. Furthermore, globalization and smaller economic borders increase the importance of traceability for products with certification of origin as a way to fight fraud and adulteration of certain products [ 88 ].…”

Selected Instrumental Techniques Applied in Food and Feed: Quality, Safety and Adulteration Analysis

“…An analogous principle is used during coconut water adulteration with sugar [211]. Coffee IRMS-based analysis includes Arana and coworkers [212], who assessed the carbon ratio of coffee from Colombia and compared it to "fingerprints" from other nearby countries. A valuable effort as will help in the efforts to guarantee the country of origin labeling.…”

Electrodeposition of 4-Benzenesulfonic Acid onto a Graphite-Epoxy Composite Electrode for the Enhanced Voltammetric Determination of Caffeine in Beverages

“…Therefore, the development of a high-quality method to quantify caffeine in different samples is of paramount importance. Many techniques have been explored over the years; for instance, ultraviolet-visible (UV-Vis) spectrophotometry [8], high-performance liquid chromatography (HPLC) [9–11], capillary electrophoresis (CE) [12, 13], FT-Raman spectrometry [14], near-infrared spectroscopy (NIRS) [15], and gas chromatography (GC) [16]. In comparison to all these techniques cited, voltammetry presents good features that encourage the increase in its use.…”