Myco-deterioration of Smoke-Dried African Catfish (Clarias gariepinus) Stored at Ambient Temperature

Abstract

The current study was carried out on moulds associated with sequential deterioration of smoke-dried Clarias gariepinus stored at ambient temperature. Samples of smoke-dried catfish were obtained from street shops, commercial vendors and as well as from neighbouring rural markets where large percentage of population used to buy for consumption. Mould infestation, nutritional composition, pH and moisture content were determined in parallel at week 0, 3 and 6. Results of the study pointed that mould load increased with storage period and ranged from 2.00 x 102 to 11.31 x 102 cfu/g. The associated moulds were identified as Aspergillus flavus, A. versicolor, A. niger, A. fumigatus, Fusarium solani, Penicillium species and Mucor species.  As the storage duration advances at the ambient temperature, the associated moulds maintained sequential succession in the smoke-dried catfish. Specifically, A. flavus and A. versicolor succeeded A. niger and A. fumigatus till week 3, and A. flavus activated the succession till week 6. Unfortunately, apart from Penicillium commune that joined the activities of P. crysogenum at week 6, other moulds were not succeeded. The crude fat, fibre, protein and ash content decreased while the moisture content of the smoke-dried catfish gradually increased. Slightly acidic to neutral pH was maintained throughout the period of storage. Our study therefore revealed that sequential myco-deterioration of smoke-dried catfish is possible when stored for long period at ambient temperature.