Comparative analysis of the proximate composition, vitamins contents, and metals profile of Nigerian rice (Oryza glaberrima) and imported rice (Oryza sativa)

Abstract

The study was designed to determine and compare the proximate composition, metals, and vitamin levels in three Nigerian rice varieties of Oryza glaberrima (Brown, Mokwa, and Ofada rice) and one imported rice of Oryza sativa. The samples were processed and evaluated in triplicate using standard methods. Brown rice had the highest carbohydrate (76.03%) content; Mokwa had the highest moisture (12.04%); Ofada had the highest protein (10.60%), and energy value (413.75 kCal/100g); the imported rice had the highest fibre content (1.53%). In terms of minerals, Brown was highest in zinc (13.83%), Ofada was highest in iron (485 %). Ofada and Brown rice had relatively high levels of lead metal. Ofada led in thiamine (0.31 mg/100g), riboflavin (0.08 mg/ 100g) and niacin (3.03 mg 100 g-1). The findings revealed that O. glaberrima Nigerian rice cultivars showed higher or at least comparable nutritive values than the O. sativa counterpart but the high level of metals like lead should incite further scrutiny.