Mycotoxins in foods--occurrence, health & economic significance & food control measures.

ABSTRACT

Mycotoxins of importance in India include aflatoxin, fumonisins, trichothecenes, ergot alkaloids and ochratoxins. The ICMR multicentric study on the occurrence of aflatoxin contamination in risk commodities namely, maize and groundnut showed that 21 per cent of groundnut samples and 26 per cent of maize samples analysed exceeded Indian tolerance limits of 30 micrograms/kg. A study on the aflatoxin intake from maize-based diets in a rural region of Andhra Pradesh showed the intakes to be in the range of 4-100 ng/kg body wt/day. Studies on the occurrence of aflatoxin M1 in milk in the southern and western regions of India indicated levels in the range of 0.05-3.0 micrograms/l. Analysis of feed samples indicated high incidence of aflatoxin B1 contamination in the groundnut cake component. Fumonisins have been shown to occur in Indian maize and sorghum. Studies showed high levels of fumonisins in rain-affected maize and sorghum consumption of which resulted in an outbreak of fumonisin mycotoxicosis in rural regions of the Deccan Plateau. A similar disease outbreak occurred in poultry due to consumption of fumonisin contaminated feed containing rain damaged maize. Biomarkers have been developed for assessing the risk of exposure for two mycotoxins viz., aflatoxin by measurement by ELISA of aflatoxin B1 N7-guanine adduct which has a detection limit of 15.6 pmol aflatoxin B1 N7 guanine; and fumonisin B1 by measurement in urine using HPLC with a detection limit of 8 ng/ml urine. Assessment of the economic implications of aflatoxin contamination showed economic losses resulting in rejection of export consignment of hand-picked-selected (HPS) groundnut and losses in the poultry industry. Approaches for prevention and control of mycotoxin contamination in foods have shown that methods involving the segregation of contaminated or mouldy grains by hand picking and density segregation resulted in a reduction of 70-90 per cent of aflatoxin and fumonisin present in the grains. While harmonization of international regulatory limits, the requirements of food producing countries needs to be recognized and realistic but not idealistic safe limits, need to be proposed.