Fungal and aflatoxin occurrence in small-scale processed dry foodstuffs sold at informal retail outlets in the Johannesburg metropolis, South Africa

Abstract

Fungal species and their mycotoxins are the most predorminant contaminants of dried agricultural products in sub-Saharan Africa (SSA) and the main species of fungi that can synthesize mycotoxins are Aspergillus, Fusarium and Penicillium. In Africa, aflatoxin is labelled as a great threat to human and animal health due to its high contamination levels reported of aflatoxins in foods. The aim of this study was to survey fungi and aflatoxin contamination of small-scale processed foodstuffs sold at informal retail outlets in the Johannesburg metropolis, South Africa. A total of 270 food samples (10 starch and legume based foods, 11 meat and fish based foods, 22 spices and local condiments, 14 dried fruits and vegetables) were collected from retailers; and analysed four (4) times in different seasons of spring, summer, autumn and winter. Out of the 270 samples analysed, only 27.8% were contaminated with fungal. Of all the six categories of foods analysed, roots and tubers (60.0%), nuts and seeds (40.0%), dried vegetables (37.1%), and the Meat and Insect foods (33.3%) respectively, had the most contaminated samples with fungal respectively. The least contaminated food groups were the fish foods (10.0%) and spices and local condiments (16.7%) respectively. Twenty percent of the 270 dried food analysed were contaminated by Aspergillus species out of which 61.1% of the contaminated samples had fungal counts above 103 cfu/g. Aspergillus niger was the most predominant Aspergillus species identified in all the categories of food samples analysed. Fruits and vegetables (24.4%) and the nuts and seeds (20.0%) food groups had the highest number of samples contaminated with aflatoxin. Peanut flour and Cardamom had the most incidence of aflatoxin. AFB1, AFB2 & AFG1 were the most prominent aflatoxin types recovered from the food samples. Almost all the food samples in which aflatoxin were identified had aflatoxin values above 10μg/ml.