Analysis, Inhibition and Degradation of Mycotoxins in Foodstuffs

Abstract

Mycotoxins are toxic natural food contaminants, mostly produced by moulds of genera Aspergillus, Penicillium and Fusarium. Cereal grains are the most susceptible food material amenable to contamination by mycotoxins. Current study adopted a multiprong approach to develop a better understanding of this major public health concern as well as devise strategies for management and control of cereal mycotoxin contamination. Initially, a comprehensive screening for aflatoxins and ochratoxin-A in various cereals from Pakistan was conducted. The results showed that 43% of samples were found contaminated with Aflatoxins. Furthermore, multi-mycotoxin contamination profile of Pakistani cereals (rice, maize and wheat) has shown prevalence of aflatoxins, trichohecence, fumonisins, zearalenone, sterigmatocystin, roquefortin-c and ochratoxin-A in cereals. The study examined the reduction of 35-51% of AFB1 during cooking of cereals following typical Pakistani recipes. The dietary exposure values for aflatoxins have exceeded the tolerable daily intake at all levels. The margin of exposure of AFB1 was remarkably lower than the recommended safe limits. The mean cancer risk values for adults and children were 0.1613 and 0.266 cancer cases/year /105, respectively. Surveillance of aflatoxins (AFs) contamination in different maize varieties can contribute to the identification of susceptible and resistant varieties, particularly for cultivation in the Pakistani agro-climatic environment. Among tested five short-season maize varieties (Pioneer, Neelam, DK-919, Desi and Hi-Corn), maximum aflatoxin levels were found in Desi (14.5±0.02 μg/kg), while Hi-corn variety demonstrated significant resistance to A. flavus and aflatoxin contamination. Myco-flora from contaminated cereal posing high risk (rice) was isolated and identified. Among the five isolated fungal genera, Aspergillus was found to be the most dominant genus. Eight essential oils were studied to inhibit A. flavus and its toxigenic potential associated with rice. The essential oils of Cuminum cyminum and Eucalyptus citriodora exhibit the maximum anti-fungal and anti-aflatoxigenic activity. The study also investigated that 71-88% of aflatoxin B1 degraded in real food medium at minimum xvii thickness (2mm) of sample exposed to UV-light after 4 hr and 48 hr of sun light. The toxicity of degraded products was much less than that of untreated samples. This study will contribute significantly to manage the mycotoxin problem in Pakistani foodstuffs.