Determination of mineral elements in fresh olive fruits by flame atomic spectrometry

Abstract

The mineral element characterisation of olive fruits is acquiring interest to evaluate the link between their nutritional status and the olive oil quality. A method for the analysis of mineral elements in fresh olive fruits is proposed. The presence of mineral elements such as potassium, sodium, calcium, magnesium, zinc, copper, iron, and manganese in olive fruits was quantified by flame atomic absorption spectrometry. The limits of quantification were (expressed in mg kg^-1 of dry weight) 1.266, 1.569, 0.272, 0.172, 0.268, 0.316, 1.017 and 0.513 for K, Na, Ca, Mg, Zn, Cu, Fe and Mn, respectively. For all of the mineral elements the precision of the instrumental method was <2.03%, and that of the analytical procedure was always ≤10%. The accuracy of the method was evaluated according to the standard additions method, the recoveries being >98% for all of the added concentrations, indicating no noticeable interference of the matrix. Finally, the mineral composition of green olive fruits of different cultivars, ‘Arbequina’, ‘Picual’, ‘Hojiblanca’, ‘Frantoio’, and ‘Bella de España’ were monitored. The levels of the evaluated mineral elements were within the working range established. The results showed the method is a robust, reliable, and simple analytical procedure for the mineral element characterisation of olive fruit.