ISOLATION AND IDENTIFICATION OF FUNGAL CONTAMINANTS ASSOCIATED WITH THE SPOILAGE OF MAIZE (ZEA MAYS) GRAINS FROM SELECTED LOCAL MARKETS IN KANO METROPOLIS, NORTHERN NIGERIA

Abstract

Fungal contamination of maize grains remains a major food safety concern, particularly in developing countries where poor storage conditions promote microbial growth and spoilage. This study investigated the isolation and identification of fungal contaminants associated with maize grains obtained from selected markets in Kano Metropolis, Northern Nigeria. Maize samples were collected from two major markets, and standard microbiological techniques were employed for fungal isolation using Potato Dextrose Agar. The isolates were identified based on their morphological and microscopic characteristics, while frequency of occurrence was determined using percentage calculations. Pathogenicity tests were also conducted to confirm the spoilage potential of the isolates. The results revealed that all maize samples were contaminated with fungi, indicating a high level of exposure to unfavorable storage conditions. Five major fungal genera were identified, namely Aspergillus, Rhizopus, Mucor, Penicillium, and Fusarium. Among these, Aspergillus recorded the highest frequency of occurrence, followed by Rhizopus, Mucor, and Penicillium, while Fusarium had the lowest occurrence. Variations in fungal distribution were observed between the markets, with higher contamination levels recorded in Dawanau Market. The pathogenicity test confirmed that all isolates were capable of causing spoilage in healthy maize grains. In conclusion, maize grains sold in Kano Metropolis are highly susceptible to fungal contamination, with significant implications for food quality and public health due to the presence of potential mycotoxin producing fungi. It is therefore recommended that improved storage practices, regular monitoring, and increased awareness among traders and consumers be implemented to reduce contamination and ensure food safety.