Decontamination of aflatoxin‐contaminated maize by dehulling

Abstract

Dehulling of maize grains as an aflatoxin decontamination method was investigated. Sixty kilograms of maize (whose average moisture content was 110 g kg −1 ) were thoroughly mixed and divided into two samples. The kernel moisture content of one sample was adjusted to 200 g kg −1 while the other (control) was left at 110 g kg −1 . The two samples were kept at ambient temperature (25-30 • C) for 21 days. Twenty sub-samples, ten from each, were further divided into two so that one lot was dehulled while the other was not dehulled. These sub-samples were then milled to pass through a 1 mm screen and the meal was evaluated for aflatoxin contamination. It was found that there was a 92% decrease in aflatoxin levels in dehulled maize meal compared with undehulled maize meal. We therefore suggest that dehulling the grain can be used to reduce aflatoxin levels in maize.

Review on the natural co-occurrence of AFB1 and FB1 in maize and the combined toxicity of AFB1 and FB1

“…Several authors have investigated the effect of various treatments on the levels of these mycotoxins by using processes that mimic the domestic treatment of maize by various population groups prior to consumption (Fandohan et al, 2005) and other commercial processes applied to maize such as extrusion cooking (Bullerman & Bianchini, 2007;Castells, Marín, Sanchis, & Ramos, 2005). Processes such as the de-hulling of maize prior to milling have been shown to result in a significantly decreased mycotoxin contamination (Fandohan et al, 2006;Siwela, Siwela, Matindi, Dube, & Nziramasanga, 2005) and most of the mycotoxins are discarded together with the bran (Siwela et al, 2005). Other physical methods of decontamination of maize grain such as removing spoiled kernels and floatation have been documented in literature (Shetty & Bhat, 1999;Sydenham, Van Der Westhuizen, Stockenstr€ om, Shephard, & Thiel, 1994).…”

Maize Storage and Consumption Practices of Farmers in Handeni District, Tanzania: Corollaries for Mycotoxin Contamination

“…Siwela et al [19] found that there was a 92% decrease in aflatoxin levels in dehulled maize meal compared with undehulled maize meal. The dehulling of maize grains either manually or mechanically before preparation of food was recommended by Siwela et al [19]. In addition to removing aflatoxins from the outer layer of maize, dehulling removes phytate and reduces the lipid content of the seed, thus improving the storage quality [19] [20].…”

“…The layers removed in the dehulling process are those which are most susceptible to fungal attack and aflatoxin accumulation [17] [18]. Siwela et al [19] found that there was a 92% decrease in aflatoxin levels in dehulled maize meal compared with undehulled maize meal. The dehulling of maize grains either manually or mechanically before preparation of food was recommended by Siwela et al [19].…”

“…The dehulling of maize grains either manually or mechanically before preparation of food was recommended by Siwela et al [19]. In addition to removing aflatoxins from the outer layer of maize, dehulling removes phytate and reduces the lipid content of the seed, thus improving the storage quality [19] [20]. When asked what was done with the defective maize detected, 73% of the farmers reported discarding it while the others said they consumed them or utilized as animal feed, mainly for chickens.…”

Management of mycotoxins in Australian maize

“…Dehulling has been shown to reduce aflatoxin levels by as much as 92% (Siwela et al 2005). If this is the case, the method may prove to be particularly useful in rendering highly contaminated loads suitable for use as animal feed in resistant species.…”