FUNGI ANALYSIS OF DRIED YAM FLOUR(AMALA) SOLD IN GBOKO MARKET, BENUE STATE, NIGERIA.

1. Introduction: Importance of Dried Yam Flour (Amala) Dried yam flour, locally known as Amala, is a staple starch food widely consumed in Nigeria, including Benue State. It is produced by peeling, slicing, drying, and milling yam tubers into fine flour, then sold in markets for preparation into a swallow food. Because it is a low-moisture food, it might appear safe, but several studies show that fungi and their metabolites can contaminate such flours during processing, handling, storage, and retailing, posing public health risks. 2. Fungi Associated with Yam Flour a. Common Fungal Genera Research on yam chips and flours in Nigeria consistently reports the presence of fungal genera capable of growth on dried yam products, including: Aspergillus spp. (e.g., A. niger and A. flavus) Penicillium spp. Fusarium spp. Cladosporium, Rhizopus, Mucor, Paecilomyces These fungi are known food contaminants in yam products sold in markets. Their spores can survive drying and contaminate the final flour through airborne transmission or unhygienic handling. 3. Mycotoxin Contamination Fungi do more than just grow on food—they often produce mycotoxins, which are toxic secondary metabolites. Several studies of yam products in Nigeria have documented: Aflatoxin B₁ and G₁ produced by Aspergillus flavus and A. parasiticus. Fumonisins produced by Fusarium species. One study found that a significant portion of yam flour samples from Nigerian markets contained aflatoxins and fumonisins, although usually within regulatory limits for foods. Another multi-mycotoxin survey reported that a high percentage of sampled Amala products were contaminated with Fusarium mycotoxins, including fumonisin B₂ and deoxynivalenol (DON), often detected at levels of public health concern. 4. Factors Influencing Fungal Contamination Several conditions common in open markets like Gboko can predispose yam flour to fungal contamination: a. High Temperature and Humidity Warm, humid climates in tropical regions favor fungal growth, especially during drying and storage. b. Poor Post-Harvest Handling If yam chips are not properly dried, stored, or milled, fungi can proliferate on the flour. Milling machines and surfaces in marketplace environments can introduce spores. c. Exposure During Retail Flour exposed in open markets without adequate protection is more likely to collect dust and airborne fungal spores, increasing contamination risk. 5. Health Implications Fungal contamination in food isn’t just a quality issue; it’s a safety concern: Aflatoxins are potent hepatocarcinogens and immunosuppressants. Chronic exposure has been linked with liver cancer, immune dysfunction, and growth impairment. Fumonisins and DON have been associated with gastrointestinal disorders and other toxic effects. Because Amala is consumed widely across age groups, contamination can contribute to chronic dietary exposure in the population. 6. Methods Commonly Used in Fungal Analysis In studies of fungal contamination in yam flour, standard microbiological and analytical methods include: a. Fungal Culturing Flour samples are cultured on selective media to isolate and identify fungal species, such as Aspergillus and Penicillium. b. Colony Counting Total fungal counts are expressed as colony-forming units per gram (CFU/g) to estimate contamination levels. c. Mycotoxin Detection Chemical analysis (e.g., HPLC) is used to quantify mycotoxins like aflatoxins and fumonisins. 7. Mitigation and Quality Control Based on evidence from similar studies, improving the safety of yam flour in Gboko (and comparable markets) may involve: Improving drying of yam chips to reduce moisture before milling Improving milling hygiene and using cleaned equipment Packaging flour in moisture-proof bags Reducing open exposure in markets Regular microbial safety testing for producers and regulators These practices can limit fungal proliferation and reduce mycotoxin formation. 8. Conclusion Fungal contamination in dried yam flour (Amala) is a recognized food safety concern in Nigeria. Studies investigating yam chips and flours from markets have identified common fungi like Aspergillus, Penicillium, and Fusarium, and documented the presence of aflatoxins and other mycotoxins, underscoring the public health risks to consumers if quality control is lacking. Improved post-harvest handling, retail practices, and regular microbiological monitoring are essential to ensure food safety and protect community health.