Ingestion Dose and Elemental Composition in Coffee by X-Ray Fluorescence and Gamma-Ray Spectrometry

Abstract

Abstract The study proposed in this paper aims to analyze macro and micronutrients in coffee powder samples from Brazil, Venezuela and Colombia, in two different stages of coffee preparation: before and after coffee filtering. In the analyzed samples, presence of K, Rb, Ca, Cl, S, Sr and Fe elements in coffee powder and coffee grounds using Energy Dispersive X-ray fluorescence (ED-XRF) was quantified. The presence of 40K and the radionuclides from the uranium and thorium series decays were verified using gamma-ray spectrometry analyses. With the results obtained using these two techniques, it was possible to estimate the ingestion index for natural radioisotopes. The results show that the annual dose due to coffee ingestion reaches 1.96(4) mSv, depending on the origin of the coffee and considering the annual coffee consumption in Brazil. Elemental Composition analysis of coffee grounds indicates that it can be reused as a product with a high concentration of nutrients.