| Mycotoxin is major kind of contaminants in cereals, it will not only cause the loss of food edible value, but also damage the health of human and annimals. Deoxynivalenol(DON),Aflatoxin B1(AFB1) and Zenralenone(ZEN) are three major mycotoxins that frequently occurs in wheats. Naturally contaminated wheat samples are collected in Henan province. The reducing partern, distribution condition and removal efficiency of thse three mycotoxins in these samples during the cleaning and milling process were studied. Besides, the mycotoxins’ effect on flour quality produced with the contaminated wheats were explored. The main results are as follows:1. The removal efficiency of mycotoxins in the industrial cleaning process was analyzed by detecting the mycotoxins’ concentration of wheat samples collected at the key steps in the cleaning process. The result showed that industrially cleaning process can remove the three mycotoxins from the low-contaminated wheats effectively, the removal efficiency for the three mycotoxins are: AFB1>DON>ZEN; During the cleaning process, the removal rate of DON was 24.36% with the concentration reduction from 1.56mg/kg in contaminated wheat to 1.18mg/kg in cleaned wheat. AFB1 reduced from 5.86μg/kg to 4.27μg/kg and reduced almost 27.13%, the concentration of ZEN reduced from 96.47μg/kg to 75.04μg/kg, and decreased 22.21% finally.The reducing partern of these three mycotoxins during cleaning process were consistent: the removal efficiency of cleaning stage for the cleaned wheat was almost triple the cleaning stage for the dirty wheat. Among all the wheat cleaning types analyzed, the dermabrasion sterilization and laser color sort were found to be the most efficient cleaning steps to remove the mycotoxins in wheat, but the removal efficiencies were a little bit different among different mycotoxins.2. The removal efficiency of these three mycotoxins during the milling process was studied by detecting the mycotoxins’ concentration of wheat fractions to find the distribution condition of the mycotoxins in wheat. The results showed that the three mycotoxins had the same distribution paetern.The toxins were concentrated in the epidermis of wheat, and gradually decreased from the outside to inside during the wheat endosperm. The removal efficiency of DON, AFB1 and ZEN were very high in the milling process, which account for 10.30%~46.96%, 29.81%~49.23% and 13.67%~51.03%, respectively.The removal efficiency was inversely proportional to the initial concentration of the toxins.3. The effect of mycotoxins on the contaminated wheats were studied. The research compared wheat kernel parameters and flour properties between contaminated wheat and normal wheat. The results showed the hardness,bulk weight, protein content, starch content,gluten content,gluten index,sussiding value, whiteness and tensile properties of silty were reduced,but the unsound grain,water content and falling number were increased after contamination. According to the scanning electron microscope observation,the epidermis had a very loose structure with many porous and hypha inside, and the internal structure of endosperm contaminated wheat was broken. The quality of flour produced with contaminated wheat declined significantly. |
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