Analysis of the quality of industrialized coffee powder using the techniques of computed microtomography and x-ray fluorescence

The culture of coffee is very important in Brazilian scenery. Brazil is the world's largest coffee producer, responsible for 30% of the planet's production, and it is among the 15 largest coffee consuming nations. More and more, consumers look for better quality of coffee, and the presence of determinate composts would prejudice the health of the consumers. Therefore, this study suggests a method to identify and quantify commercially roasted ground coffee impurities/contaminants using computed microtomography (micro-CT) and x-ray fluorescence (XRF) techniques. A set of different commercially roasted ground coffees were investigated. The micro-CT results showed that most of the coffee powder samples analyzed showed some contaminant, and in a specific brand, the amount of contaminants was higher than 9%. The 3D data provided information about the size and shape of these contaminants. The XRF results showed the macro elements P, S, Cl, K, and Ca and the micro elements Mn, Fe, Cu, Zn, Rb, and Sr. The elemental concentrations are in agreement with the values reported in the literature, except for the same specific brand, where the values found were much higher. The combined data of both techniques showed that the amount of impurities/contaminants in the ground coffee results in an increase of the macro and micro nutrients and also modifies the flavor and fragrance of the product, leading to an overall poor quality of the final beverage.