Paper Contents
Abstract
Postharvest spoilage of fruits causes significant food losses globally. This study identified fungal species associated with the spoilage of sweet orange (Citrus sinensis) and bitter lemon (Citrus limon) in Katsina metropolis, Nigeria. Sixteen spoiled fruit samples were purposively collected from markets and farms. After surface sterilization with 1% sodium chloride, infected tissues were cultured on Potato Dextrose Agar (PDA) and incubated at 37C for 37 days. Fungal isolates were identified based on macroscopic (colony morphology and pigmentation) and microscopic (spore and hyphal structure) characteristics. The fungi identified included Penicillium oxalicum, Aspergillus flavus, Rhizopus stolonifer, Fusarium incarnatum, Mucor fragilis, Endomyces, and Curvularia. These were linked to spoilage symptoms such as soft rot, black rot, and brown discoloration. Penicillium oxalicum and Aspergillus flavus were most prevalent, with the latter being notable for its aflatoxin production, posing serious food safety risks. Rhizopus stolonifer was associated with soft rot, while Fusarium incarnatum produced pink-centered colonies. Yeast-like Endomyces appeared in early spoilage of sweet lemons, contributing to fermentation and off-flavors. Differences in fungal colonization were observed: sweet lemons favored yeast and Aspergillus species due to higher sugar content, while bitter lemons, though less penetrable, supported aggressive molds like Rhizopus and Penicillium. These findings highlight the complexity of fungal spoilage and the importance of early detection, proper storage, and handling to prevent postharvest losses and mycotoxin contamination in citrus fruits.
Copyright
Copyright © 2025 Zakari H.H, Gafai M.M, Jalo A., Suleiman A.I, Nasiru A., Ilyasu M, Yasrab M. This is an open access article distributed under the Creative Commons Attribution License.
