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

INTRODUCTIONpolarity. Pujol et al., (1999) concluded that steeping corn kernels in 0.2% SO 2 solution at 60°C for 6 his very effective to decrease the amount of FB1.Ochratoxin A is distributed differently in the corn steeping process, and the toxin remains in thesteeped corn, and do not reach into the steep water (Wood, 1982).2) Inactivation in contaminated maizea) Heat treatmentMost of mycotoxins are heat-stable within the range of conventional food/feed processingtemperatures (80-121°C), so little or no destruction occurs under normal cooking conditions such asboiling and frying, or even following pasteurization. The sensitivity of mycotoxins to heat treatment isaffected by many different factors including moisture, pH, and ionic strength of food. Degradation byheat treatment also depends on the type of mycotoxin, its concentration, the extent of bindingbetween the mycotoxin and the food constituents, the degree of heat penetration, and theprocessing time (Kabak et al., 2006). A heat treatment which has been widely studied for thedestruction of some naturally occurring food toxins, is extrusion cooking process. The reduction ofthe mycotoxin in the finished products depends on several factors including extruder temperature,screw speed, moisture content of the extrusion mixture, and transit time in the extruder. Of thesefactors, extrusion temperature and transit time seem to have the greatest effect. The highestreductions in mycotoxin concentrations in extruded products occur at temperatures of 160°C orgreater, and when time of transit is increased. During extrusion cooking, the raw material issubjected to high temperatures, high pressure, and severe shear forces. Two major types of extruderare used in the food industry : single-screw and twin-screw extruders.Hameed (1993) showed that extrusion alone was able to reduce aflatoxins content in naturallycontaminatedcorn by 50-80%, and with addition of ammonia, either as hydroxide (0.7 and 1.0%) oras bicarbonate (0.4%) the aflatoxin reduction achieved was greater than 95%. However, Cazzaniga etal., (2001) emphasizes the importance of the extruder design, which could be a significant factoraffecting the residence time and the degree of mixing.In addition to this heat process, roasting is also effective in the detoxification of aflatoxincontaminatedcorn. Reduction in aflatoxin content was higher when roasting was combined withammonia treatement (Conway et al., 1978).Extrusion appears to be an effective method for reducing fumonisins levels in corn (Castelo et al.,1998a; Katta et al., 1999). In the study of Katta (1999), the FB1 losses in corn grits at different57