Effect of Heat Treatment on Aflatoxin Contents of Tomatoes Samples in Ilorin, Kwara State, Nigeria

Abstract

Fungi contamination of agricultural products had been one of the major concerns to human due to their possibility of causing spoilage and the potential of producing potent toxins that could constitute health problems. Therefore, this study evaluates the effect of heat treatment on aflatoxin contents of tomatoes samples in some selected market in Ilorin, Kwara State, Nigeria. The spoilt and fresh tomatoes samples were randomly purchased from nine vendors for analysis. Fungi were isolated on Sabroud dextrose agar and identified using colonial and morphological characteristics. The levels of aflatoxin in the samples were determined using ELISA techniques and effects of heat treatments on aflatoxin levels of the samples were determined before and after 5, 15, 25 and 35 minutes of heat treatments at 100 oC. The results revealed the presence of fungi contaminants in all the analysed samples irrespective of their quality status. Furthermore, the aflatoxins contaminants were not detected in all the evaluated fresh samples; whereas the presence of aflatoxin in the spoilt samples was observed. The average aflatoxin contents of spoilt samples were 7.83, 8.17 and 8.62 μg/kg respectively, with no significant differences among the values. The effect heat treatments on the aflatoxin contaminated samples were observed to be time dependent. About 7.5 % non-significant reductions (p > 0.05) in aflatoxin contents of the samples were observed after 5 min of heat treatment. While, significant reduction of about 45.0 %, 53.1 % and 71.5 % were observed after 15, 25 and 35 minutes of heat treatments respectively. This is an indication that proper cooking at 100 oC, over a period of time could significantly reduce aflatoxin level in some food products that are usually subjected to cooking prior to consumption