Distribution of aflatoxins in contaminated corn fractions segregated by size

Abstract

The efficiency of segregation, by particle size, in reducing the aflatoxin content of corn lots under the Brazilian conditions was studied. The aflatoxin content, in the corn fractions obtained after sieving thirty contaminated samples, with approximately 3.0 kg each, was determined. The samples were passed through 4.5 mm round-hole sieves and the fractions with particles ³4.5 mm (fraction A) and <4.5 mm (fraction B) and then analyzed for aflatoxins by TLC. The results showed that the distribution of the aflatoxins among the fractions A and B varied from sample to sample. However, the fraction B presented higher content (6 to 1,422 µg/kg) of aflatoxins (P<5%), than samples of fraction A (4 to 389 µg/kg). In spite of that the segregation of this fraction did not reduce significantly the contamination of the samples. This probably occurred because the contribution of the fraction B for the estimated total of the concentration of aflatoxin of the sample was smaller than that of the fraction A, due to the smallest amount of the fraction B in the sample weight total. In spite of being significant for the studied samples the correlation among the percentages of the groups of grains with defects a) burning grains, sprouted, burned and moldy and b) total injured, with the estimated level of contamination for the samples, more studies will be necessary so that better conclusions can be drawn for this correlation.

Chemical Composition of Distillers Grains, a Review

“…Therefore, separation of these components (kernel fractionation) prior to fermentation could be advantageous for increasing the value of coproducts. For example, dehulling grain kernels can effectively reduce mycotoxins concentrations. , Also, broken kernels are known to be higher in aflatoxins, and they can be removed by sieving due to smaller particle size …”

“…102,103 Also, broken kernels are known to be higher in aflatoxins, and they can be removed by sieving due to smaller particle size. 104 For ethanol coproducts, Lillehoj et al 95 detoxified aflatoxin B 1 in whole stillage with sodium hydroxide, ammonium hydroxide, sodium hypochlorite, and hydrogen peroxide. Bennett et al 105 reduced zearalenone in fermentation solids with formaldehyde.…”

Decontamination of aflatoxin‐contaminated maize by dehulling

“…Segregation of kernels by particle size has also been used. It was shown that larger grains (>4.5 mm) contained significantly lower aflatoxin levels than those smaller than 4.5 mm 5. Heat treatment such as cooking6 and dry roasting7, 8 have been reported to reduce aflatoxin concentration.…”

Aflatoxin Contamination Distribution Among Grains and Nuts

“…Besides the high correlation between aflatoxin and size, infected grains and nuts can be more friable than not infected ones (Shotwell et al, 1974), therefore the handling of the product can generate fragments, as shown in figure 3, of infected material, and it can contribute to the total aflatoxin level of the lot (Meinders & Hurburg, 1993;Piedade et al, 2002). Therefore, segregation by size has been studied as a way to remove aflatoxin contamination in commodities lots.…”

“…Cole et al (1995) reported that using a farmer stock peanut the sizing and electronic color sorting process were responsible by 29 and 70% of the aflatoxin reduction. Piedade et al (2002) investigated the aflatoxin segregation when a sieve of 4.5 mm of round-holes was used to sieve maize samples and they observed that the largest grain fraction had lower average levels (84.8 µg/Kg) than the smallest one (204.0 µg/Kg). However, due to weight participation of each fraction in the total sample weight, the contribution of the smallest fraction was lower than the largest, so the segregation by size would not be able to reduce the aflatoxin leves in the whole sample.…”