Mould contamination of ready-to-eat cereal-based foods retailed in Lesotho with special reference to toxigenic aspergillus flavus

• Published in: African journal of food, agriculture, nutrition, and development : AJFAND Vol. 11; no. 47; pp. 5318 - 5334
• Main Authors: Mohale, S, Allotey, J
• Format: Journal Article
• Language: English
• Published: 25.11.2011
• ISSN: 1684-5374; 1684-5374
• DOI: 10.18697/ajfand.47.10530

Samples belonging to four different brands ( Instant Morvi te™, E -Papa™, Ace Instant Porridge™ and Roasted Morvite™) of ready -to-eat fortified cereal -based foodstuffs imported from the Republic of South Africa were bought from different retail outlets in the Roma valley , Lesotho and examined for contamination with moulds. All (100%) of Roasted Morvite™ and E-Papa™ examined were contaminated with fungi. The greatest average fungal load (1.33 × 10 5 ) was recorded on Roasted Morvite™ sample s. Although all the E -papa™ samples were contaminated, the upper limit average m ould load ( 1.0 × 10 4 ) was the lowest compared to other brands that were analysed . A total of 226 isolates belonging to five different genera ( Aspergillus , Penicillium , Cladosporium , Wallemia and unidentified genus) were recovered. For each of the brands assessed, average mould counts for some samples were above maximum permissible limits (10 3 CFU/g) established by World Food Programme guidelines for fortified blended foods. Aspergillus and Penicillium isolates exhibited greatest fungal population densities, 52.7%, 36.3% , respectively. Wallemia was the least frequently isolated genus in this study; only four isolates (1.8%) recovered from all the samples investigated belonged to this genus . Of the Aspergillus species isolated, A. niger had the greatest relative density (39.5%) followed by A. flavus (37.8%) , while Aspergillus amstelodami and unidentified Aspergillus species had the lowest. Of the 22 A. flavus isolates tested for sclerotia production potential, 18 produced large sclerotia with average diameter > 400.02±82.61 on Czapek solution, agar. Ten (56%) of these isolates were toxigenic as evidenced by formation of a blue fluorescence on the reverse of the plates when observed under UV (365 nm) . It was conclude d that the detection of above -permissible limits levels of moulds and aflatoxigenic fungi in some samples analysed presents a risk to consumers’ health. It is, therefore, suggested that a statutory, independent and science -based body dedicated to protecting public health and consumer interest in the area of food safety and hygiene be established. The main function of such a body would be to take all reasonable steps to ensure that food produced, distributed or marketed in Lesotho meets the highest standards of fo od safety and hygiene available.