Seasonal variation on mineral profile in rice varieties of Sri Lanka

Abstract

Rice (Oryza sativa L.) is the backbone of Sri Lankan agriculture with the accomplishment of the daily nutritional requirements of humans. This study is intended to explore the cultivation seasonal variation on minerals in selected rice varieties and to examine the possible health risks due to toxic heavy metal contamination. Twenty-six different rice varieties cultivated during Maha (2018/2019-from September to March) and Yala (2019-from May to end of August) seasons were analyzed for selected twenty elements using intra-laboratory validated test methodologies combined with ICP-MS and UV–vis spectrophotometry to determine possible variations of these parameters due to cultivation seasonal differences. The concentrations of As, Cd, Pb, and Se of all analyzed rice varieties were lower than the maximum levels stipulated by FAO/WHO guidelines suggesting them to be suitable for human consumption. The present study revealed that selected rice varieties in Sri Lanka to be a potential source of valuable minerals such as, Fe, Zn, K, Ca, Mg, Na, P and the cultivation seasonal variation has a significant positive impact on the mineral profile of rice. Moreover, ANOVA, PCA, and PLS analysis confirmed that there was a distinct variation of the profile for minerals and heavy metals of analyzed rice varieties.