Mycological Evaluation and Occurrence of Aflatoxins and Ochratoxin A in Tilapia Oreochromis niloticus Fish and Fish Products

A total of 100 random samples of whole Tilapia (Oreochromis niloticus) and fillet of Tilapia (50 of each) were collected from different fish markets in Gharbia Governorate to evaluate pH, mycological contamination, and their total aflatoxin and ochratoxin A residues. The obtained results revealed that the mean ± SE pH values were 6.1± 0.05 and 6.3± 0.03 and the mean total mould count values ± SE were 3.63 × 102± 8.75×10 and 1.65×102 ±4.78×10 cfu/g of whole Tilapia and fillet of Tilapia, respectively. It was found that the mean value of the total aflatoxin (µg/kg) in the examined samples were 0.55± 0.2 µg/kg for whole Tilapia and 0.68± 0.06 µg /kg for the fillet samples. Whereas the mean values of ochratoxin A were 2.79 ± 0.6 µg/kg for and 0.12 ± 0.01 µg /kg for the whole tilapia and fillet, respectively. Six fungal species were identified in the current study. The most prevalent fungal species were Aspergillus niger, followed by A. flavus. However, the least dominant were A. terreu, A. westerdijkiae, and A. pseudocaelatus, Alternaria alternate, Cladosporium cladosporidiae, Mucor species and Penicillium species. In conclusion, the investigated whole tilapia and fish fillet is contaminated by mould. Aflatoxin and ochratoxin were detected in the examined samples. Therefore, continuous monitoring of the occurrence of mycotoxins in the retailed fish and fish products are highly recommended to ensure product safety.