Mycological Assessment and Aflatoxin Contamination of Smoked-Dried Fish from Open Markets

Smoked-dried fish is a vital, affordable protein source in Nigeria, yet traditional processing and storage methods often predispose these products to fungal proliferation and hazardous mycotoxin accumulation. This study aimed to evaluate the mycological quality and aflatoxin levels in smoked-dried fish sold in major markets in Awka, Anambra State.

Thirty-eight samples of smoked-dried fish were randomly collected from local Open markets. Fungal isolation was performed using Potato Dextrose Agar (PDA), with identification based on macroscopic and microscopic morphological characteristics. Total aflatoxin (AF) and aflatoxin B1 (AFB1) concentrations were quantified using Enzyme-Linked Immunosorbent Assay (ELISA).

Fungal contamination was prevalent across all samples, with Aspergillus species being the dominant genus. Aflatoxins were detected in 60% (9/15) of the samples, with total concentrations ranging from 1.8 µg/kg to 18.6 µg/kg. The mean total aflatoxin concentration was 8.42 ± 5.37 µg/kg. While 13.3% of samples exceeded the Codex Alimentarius limit (10 µg/kg), a significant 40% exceeded the more stringent European Union limit for AFB1 (2 µg/kg). Notably, samples containing Aspergillus flavus showed significantly higher toxin levels (14.25 ± 3.11 µg/kg) than those without (3.96 ± 1.87 µg/kg).

The high frequency of aflatoxin contamination, particularly levels exceeding international regulatory thresholds, poses a significant public health risk to consumers in the region. Improved processing hygiene and moisture-controlled storage are urgently required to mitigate mycotoxin exposure.