Analytical Techniques for the Determination of Elemental Composition of Coffee

According to the Coffee Market Report (2024) of the International Coffee Organization, the annual worldwide production of coffee increased 5.82% achieving 178 million bags between 2023 and 2024. South America is the coffee production leader accounting for 50.17% of the global production with Brazil playing a central role on it. To sustain the high quality standards under such a high demand, it is important to ensure the consumer health safety, while preserving the good flavor and aroma of coffee (terroir). Some key factors are required to allow the proper evaluation of crops and shipments using reliable parameters, which is the case of the determination of the elemental composition of coffee. Coffee organoleptic properties depend on several chemical elements of its composition, while accessing and monitoring their concentrations is challenging, since they might vary considerably according to some agronomical and climatic conditions that plantations are subjected. Yet, the analytes might not be homogeneously distributed throughout samples, demanding both refined solid sampling strategies and laborious sample preparation and pretreatment. Finally, several analytical techniques are available for researches and analysts to investigate the elemental composition of coffee samples, each one with their own advantages, limitations and particularities. Sometimes it is not a trivial task to choose a proper technique according to the aimed data. Therefore, an overview of the analysis of coffee elemental composition is herein presented, covering selected references from the last two decades. The selected works discuss the determination of elements affecting the quality of coffee in terms of terroir, toxicity, nutritional content, and geographical origin.