Effet chez le porcelet d'une exposition à un régime co-contaminé en ...

INTRODUCTIONfound to be suppressed in the presence of aflatoxin, remained unimpaired when the applied AFB1was pretreated with 1.2 mg/L ozone for 6 min at a flow rate of 40 mL/min (Chatterjee andMukhergee, 1993). However, the ozonation process may cause formation of fat-soluble reactionproducts with low mutagenic potential (Prudente and King, 2002).McKenzie et al. (1997) found that treating an aqueous solution of fumonisin B1 with 10 wt%ozone gas for 15 sec resulted in the conversion of the parent compound to the 3-keto FB1 derivative.In two separate toxicity tests, 3k-FB1 was found to retain most of the toxicity present in the parentcompound (see Table 7). Therefore, a further degradation of FB1 to a product less active than 3k-FB1is needed (i.e. removal of primary amine).Moisture appears to be essential in the reaction between deoxynivalenol and ozone. Moist ozone(1.1 mol %) in air resulted in a 90% reduction in DON-contaminated corn, at 1000 ppm, after 1h,while dry ozone resulted only in a 70% reduction (Young, 1986). For DON treatment with ozone,differences also occur between wheat and corn. A matrix effect was suggested (Young et al., 2006),the ground corn being more porous, whereas ozone may not be able to penetrate the whole wheatkernels as readily. Young et al. (2006) reported the degradation of several trichothecenes mycotoxinsby aqueous ozone and on the basis of UV and MS data, proposed that the degradation begins withattack of ozone at the C9-10 double bond with the net addition of two atoms of oxygen. However,toxicity of the breakdown products and efficiency of this technology in maize need to be evaluated.Ozone treatment induces a rapid degradation of zearalenone level in water solutions containing12 ppm of ZEA (Lemke et al., 1999), and prevents its estrogenic effects (see Table 7). In an in vitrostudy a reduction to undetectable levels was observed after ozone treatment for 15 s in ZEA solution.No new products were observed after the treatment (McKenzie et al., 1997).The same study showed treatment of aqueous solution of ochratoxin A with 10 wt% O 3 for 15seconds reduced the mycotoxin level to undetectable levels, and a bioassay revealed a decrease inthe toxicity (see Table 7).Using ozone to purify commodities, the commercial Oxygreen ® process claims the destruction ofmycotoxins found on grain by bringing them to levels tolerated by legislation. This procedure lead toa 94% reduction of OTA in grains. Toxicity of this process was evaluated by a four-week study in ratsby dietary administration of treated wheat, and the treated products were considered as safe for theconsumer (Gaou et al., 2005).3) NixtamalizationNixtamalization, a Mexican traditional process for making tortillas, consists of the cooking ofmaize grain in abundant water and lime (calcium hydroxide), at temperatures near boiling, followed63