Exploring the elemental variations in commercial non-glutinous brown and white rice from Malaysia by chemometrics

Abstract

The concentrations of Na, Mg, K, Ca, Mn, Fe, Cu, and Zn in a selection of commercial non-glutinous rice sampled from Malaysia were determined using microwave assisted digestion with inductively coupled plasma-mass spectrometry and the data obtained were evaluated using chemometric techniques. Both principal component analysis and hierarchical cluster analysis revealed two distinct clusters where the brown rice is associated with higher elemental content compared to the white rice; and Mg level was identified as a key discriminatory factor according to linear discriminant analysis outcomes. The concentrations of macroelements used to exhibit a consistent sequence: K > Mg > Ca > Na; whereas no regular trend was observed on the microelements. The results suggested that the elemental variations in the rice samples were largely attributed to the grain treatment processes while the impacts of the other underlying factors are more apparent on microelemental concentrations. From the nutritional assessment, brown rice appeared to be a noteworthy dietary source of Mg, Mn, and Zn, however, the contributions of Na and Ca to daily needs are negligible.