engleski

In situ reduction of aflatoxin B1 level by gamma irradiation

Various commodities predominantly crops can be contaminated with moulds that can lead to economic losses in agriculture and in food industry. More importantly, some moulds produce mycotoxins, their toxic secondary metabolites, indicating that mould except economic loss can represent threat to animal and human health. Oneof the most toxic mycotoxin is aflatoxin B1 (AFB1) with hepatotoxic, teratogenic, immunosuppressive and carcinogenic properties. Due to its toxicity International Agency for Research on Cancer (IARC) classified AFB1 in group 1 as carcinogenic to humans. Countries around the world have limited the maximal level of mycotoxins in different food and feed commodities and in EU maximal tolerable level of AFB1in cereals and cereal-based products is set to 2.0 μg/kg. The level of AFB1in various commodities depends on climatic conditions under which the crops are harvested, stored and processed and higher AFB1level can be expected with higher humidity and temperature that favourable mould growth. It is important to try to control growth of moulds that can produce AFB1, or at least to keep their growth and production of AFB1to minimum. It is known that gamma irradiation could be effective in inactivating the growth of moulds, thus reducing AFB1level in commoditiesindirectly. The aim of this study was to investigate if gamma irradiation can be use as a method for direct reduction of AFB1level in corn/feed samples intended for animal consumption. For this purpose two separated experiments were performed. In the first experiment corn seeds, ground corn seeds and feed samples were artificially contaminated with known AFB1concentration (50 or 100 μg/kg), that can be expected in nature. For the second experiments corn seeds samples (n=30) naturally contaminated with AFB1and intended for animal consumption were collected inEastern part of Croatia. In both experiments gamma irradiation at 5 and 10 kGy were tested. Results of first experiment showed that gamma irradiation of feed samples with added AFB1at dose of 5 kGy reduced AFB1level for around 65%, while at dose of 10 kGy AFB1level was reduced for around 85%. In naturally contaminated corn samples overall reduction of AFB1level after 5 kGy irradiation was 69.8% while the overall mean toxin reduction was 94.5% when 10 kGy was applied. Together, these results indicate that gamma irradiation can be used in reducing AFB1level in various commodities intended for animal and human consumption thus minimizing animal and human exposures to this carcinogenic mycotoxin.

mycotoxins; aflatoxin B1-reduction; gamma irradiation

nije evidentirano