PIXE characterisation of natural and industrial spices: A nutritional assessment study

Abstract

Elemental contents of naturally grown and industrially processed spices were determined for the nutritional benefits and assessment. The low temperature oven-dried samples were pulverised and self-supporting pellets made in triplicates. Elemental analysis was carried out using 2.5 MeV proton beams from a Particle Induced X-ray Emission (PIXE) spectrometric setup. Twenty-three elements: Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo, Sr, Bi, V, Al, As, Pb, Po, Th and U were quantified. A Kapton-90 filter was used to attenuate bremsstrahlung contributions from high counts of low-Z elements, yielding optimal signal-to-background ratio required for better quantification of low peaks from high-Z elements. The low-Z elements counts were then corrected for underestimation by evaluating the amount of absorption. The concentrations of Pb, Po and As were below the maximum allowable levels. The essential elements: Mn, Fe, Co, Cu, Zn and Sr had high concentrations in most of the samples while elements like Pb and Cr could add to the heavy metal burden in human body, since they are capable of posing serious health challenges. A robust quality control measures for the cultivation and processing of spices is suggested to ensure the safety of the consumers.