Impact of Fungal Contamination on Nutrient Composition of Rice, Maize, and Sorghum in Nigeria: Correlation Analysis and Implications for Food Quality

Abstract

This study assesses the effect of fungal contamination on the nutrient composition of staple cereals, rice (Oryza sativa), maize (Zea mays), and sorghum (sorghum bicolor) - widely consumed in Nigeria. A total 23 sample of maize (7), rice (6) and sorghum (9) were analyzed for fungal colony- forming unit (CFUs) via plate dilution method and nutrient composition (moisture, ash, fat, fiber, protein and carbohydrate levels) was measured using Association of Analytical Chemist (AOAC) methods. Statistical analysis including Spearman correlation was applied using SPSS software. Maize showed the highest fungal contamination with a mean CFU of 4.0 x 105 CFU/g, followed by sorghum at 3.7 x 104 CFU/g, while rice had the lowest at 2.7 x 104 CFU/g. Significant positive correlations were observed between fungal growth and moisture content in all grains, with correlation coefficient of 0.752 for rice, 0.806 for maize and 0.055 for sorghum. Conversely, carbohydrate content showed a significant negative correlation in all samples, notably in maize (-0.860) and rice (-0.638) with (-0.462) for sorghum. Fat and fiber showed a negative correlation in rice (-0.584) and maize (-0.488), while sorghum showed a positive correlation (0.413). Only rice showed a negative correlation for ash (-0.415) and protein (-0.136), while maize (0.354 and 0.220) and sorghum (0.258 and 0.384) showed a positive correlation. These findings underscore the nutrient losses due to fungal contamination, highlighting the necessity for enhanced post-harvest storage to mitigate contamination and preserve cereal nutrient quality.