Determination of the Levels of selected essential and non-essential metals in the unprocessed and processed Tomatoes from commercial market of Jimma City

Abstract

Tomato is one of the most important edible nutritional vegetable and accumulates essential and non-essential metals. Tomatoes have, undoubtedly, assumed the status of a food with functional properties, considering the epidemiological evidence of reducing the risk of certain types of cancers. In this study, the concentration of essential and non-essential metals in unprocessed and processed tomato samples was evaluated. After sample preparation, and digestion the levels of those metals in tomatoes were determined by atomic absorption spectrometry (AAS). The experimental results of each tomatoes, the mean concentration of essential and non-essential metals (mg/g) in unprocessed tomato sample exhibited decreased tend in the order of k, (20.23 ± 0.28) > Ca, (2.02 ± 0.01) > Cd, (0.072 ± 0.001) > Pb, (ND), while mean concentration for the processed tomato samples follow the decreasing order of K, (21.32 ± 0.42) > Ca, (1.92 ± 0.01) > Cd, (0.098 ± 0.001) > Pb, (ND), slightly a significant difference was observed between the mean concentrations of all metals in tomato. This indicates that the tomato sample contain the higher level of some selected essential metals than non-essential metals in unprocessed and processed tomatoes samples, and in the precision test, %RSD (relative standard deviation) for selected essential and non-essential metals in unprocessed and Processed tomato sample was in the range between 1.4% to 6.9% and 1.9% to 10%, for both tomato samples in commercial market of Jimma city. Therefore, the content of essential and non-essential metals such as Ca, K, Cd and Pb in unprocessed and processed tomato samples was below the permissible value of WHO/FAO.