Road-side roasted plantain and maize in Zaria and environs: nutritional composition and heavy metal evaluation

Abstract

This study aimed to assess the nutritional quality and heavy metal contamination of roasted and raw corn and plantain marketed in Zaria and its vicinity. Raw and roasted plantain and maize were obtained from three distinct areas of Zaria. The samples were air-dried and ground into powdered flour for analysis. Moisture content was lowest in roasted plantain (4.67±0.54%) and highest in raw maize (9.58±0.60%). Crude protein and crude fibre were most elevated in roasted maize samples (10.56±0.26, 3.22±0.13%, respectively) and lowest in raw plantain samples (8.62±0.37, 1.70±0.20%, respectively). Ash content was highest in raw plantain (3.28±0.16%) and lowest in roasted maize samples (2.00±0.26%). Nitrogen-free extract (NFE) was significantly higher (P <0.05) in both raw (78.42±0.64%) and roasted plantain (78.63±1.14%). The mineral composition of roasted road-side plantain (Ca, 0.22±0.04; Ph, 0.11±0.03) and maize (Ca, 0.23±0.02; Ph, 0.22±0.00) reveal that calcium and phosphorus were found within the moderate limit adequate for human consumption. Based on the current study, raw and roasted plantain and maize across all the study locations were highly contaminated with Pb, Cr, and Cd, which may pose a public health concern.