Comparative study on the nutrients, heavy metals and pesticide composition of some locally produced and marketed rice varieties in Nigeria.

The nutrients, heavy metals and pesticide concentrations of an imported (Gold) and three locally produced and marketed rice varieties (Samples B-mass, C-R8 and D-CP) in Nigeria were investigated using standard techniques. All the rice varieties contained considerable amounts of moisture, ash, protein, lipid and carbohydrate but were low in crude fibre. The local rice varieties contained higher (P < 0.05) amounts of tryptophan and tyrosine than the imported rice. Sample C had the highest amino acids contents compared with other rice varieties. The threonine contents of the control and sample B were higher than WHO standards. Lead and mercury were not detected in all the rice varieties while the levels of cadmium, arsenic, chromium and thallium were within permissible range. The rice varieties contained considerable amounts of selenium, calcium, iron, manganese, zinc, phosphorous, boron, cobalt, Vitamins A, D, B6, thiamine, riboflavin, niacin and cobalamin with insignificant amounts of pesticide residues.