Elemental Characterization between Single Origin Arabica and Peaberry Robusta from Vietnam

Coffea arabica and coffea canephora (robusta) are the two most common species of coffee. With the rising price and rising global demand for coffee there is an increasing incentive for distributors to pass cheap coffee as more expensive coffee creating a need to verify the authenticity of coffee. This research was conducted to perform elemental characterization of Nguyen brand arabica and robusta coffee grown in Vietnam. The coffee beans were ground and digested by nitric acid digestion. The samples were run using inductively coupled plasma atomic emission spectrometry (ICP-AES) and compared with prepared standards containing calcium, iron, rubidium and manganese. Standard calibration for each element was created from which the element concentration in the coffee samples were determined. The elemental ratio between manganese and calcium in arabica, was approximately double the ratio between manganese and calcium in robusta. The elemental ratio between iron and manganese in arabica was approximately half the ratio in robusta. The elemental ratio between rubidium and manganese in arabica was also approximately half the ratio in robusta. The elemental ratios were compared to confirm that the two species of coffee grown in Vietnam were different. The results showed that the robusta absorbs more iron than arabica when standardized with manganese