Mineral contents in grains of seven food-grade sorghum hybrids grown in a Mediterranean environment

Mineral nutrients play a fundamental role in the biochemical and physiological functions of biological systems. Cereals may especially be an important source of essential minerals in view of their large daily intake both for human health and nutrition. Sorghum, among the cereals, is a major crop being used for food, feed and industrial purposes worldwide. The objective of this study was to determine the mineral contents in grains of seven white food-grade sorghum hybrids, bred and adapted for growth in the central USA and grown in a Mediterranean area of Southern Italy. The seven hybrids were analyzed for grain ash and for minerals contents. Nutritionally, essential macro-, micro- and trace elements content were investigated. The analysis of essential elements was performed by mass spectrometry using a mix solution of internal isotopes standard. The results demonstrated that food-grade sorghum was characterized by high Mg, Fe and Zn content, high K:Na ratio and low Ca:P ratio, compared to other crops, due to the fact that the grain mineral contents of crop species are influenced by the effects of genotypes and environments. Significant variations in the essential elements content were found among the hybrids which allowed us to divide them into three distinct groups on the basis of their mineral profile by cluster analysis. These results are discussed with reference to the importance of minerals in human nutrition and suggest that, like wheat, it is possible to plan research programs for the improvement and selection of sorghum hybrids with high micronutrients content.