Effect of different storage conditions on aflatoxin production in oven-dried tilapia fish (Oreochromis niloticus)

Abstract

Aflatoxin produced by Aspergillus species are carcinogenic and pose significant health risks to consumers of contaminated food  products.The storage conditions of oven-dried fish play a crucial role in controlling aflatoxin production. This study examined aflatoxin  production in oven-dried tilapia fish under different storage conditions. A total of 36 fishes were bought fresh, oven-dried and stored in  bamboo baskets and plastic containers. The isolation and Identification of fungi were carried out weekly for 4 weeks and and aflatoxin  was detected by high-performance liquid chromatography (HPLC) method. The highest moisure content (%MC) of the oven-dried Tilapia  fish were subjected to temperature ranges 80 °C - 130 °C was 76.7% at 130 °C. The total fungal count ranges from 2.65±0.01 to 3.31±0.02  log cfu/g with the highest count recorded in covered bamboo basket while the lowest was from tightly covered storage plastic. Six fungal  isolates namely Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, mucor, yeast, and Penicillium chrysogenum were associated  with the stored ovendried tilapia fish samples. The oven-dried tilapia fish stored in bamboo baskets (opened and closed); and opened  plastic container were contaminated with three (3) Aspergillus sp. and a Penicillium sp. with aflatoxin B1 levels ranging from 0.62 to 0.90  ppb. Remarkably, no fungi or aflatoxin were detected in the tightly covered storage plastics (TCSPs) containing fish that were oven-dried  at 130 °C (designated as A) in sharp contrast to bamboo basket-stored fish which exhibited elevated fungal counts. The results obtained  from this study highlights the critical function of storage conditions in controlling aflatoxin production in oven-dried tilapia fish. The  application of best storage practices can decrease contamination, ensuring safer consumption and reduced health risks.