Mycological Assessment Of Post-Harvest Fungal Spoilage Of Cocoyam (Colocasia Esculenta) Marketed In Abia, Southeastern, Nigeria

Abstract

Postharvest fungal spoilage of cocoyam (Colocasia esculenta) remains a major challenge affecting food security, market value, and consumer safety in Nigeria. This study assessed the fungi associated with postharvest spoilage of cocoyam marketed in Aba, Abia State, Southeastern Nigeria. A laboratory-based experimental design was adopted. Fifteen cocoyam tubers were purchased from Ariaria Market, Aba, allowed to undergo spoilage under ambient conditions, and analyzed using standard microbiological and mycological techniques. Fungal isolates were cultured on Sabouraud Dextrose Agar (SDA), identified based on cultural and morphological characteristics, and their occurrence determined using colony counts and percentage frequency.The results revealed the presence of four fungal genera, namely Mucor spp., Rhizopus spp., Aspergillus spp., and Penicillium spp. Cultural and microscopic examination showed characteristic colony morphologies that aided identification of the isolates. The fungal load varied among the isolates, with Penicillium spp. recording the highest count of 2.1 × 10⁸ CFU/ml, followed by Aspergillus spp. (7.0 × 10⁷ CFU/ml), Rhizopus spp. (4.7 × 10⁴ CFU/ml), and Mucor spp. (8.0 × 10¹ CFU/ml). Percentage occurrence analysis indicated that Mucor spp. was the most prevalent isolate, accounting for 36.7% of the total colonies, followed by Rhizopus spp. (32.1%), Aspergillus spp. (21.6%), and Penicillium spp. (9.6%).The study concluded that fungal contamination is a major factor responsible for cocoyam deterioration during storage and marketing in Aba. The occurrence of potentially toxigenic fungi such as Aspergillus and Penicillium highlights possible food safety risks. Improved postharvest handling, storage conditions, and routine microbial monitoring are therefore recommended to reduce spoilage losses and enhance the quality and safety of cocoyam for human consumption.