中文摘要：玉米是美国生产乙醇的主要原料。为了减少浪费及人畜毒性，将黄曲霉毒素污染的玉米用在生物燃料产业是合理的。然而副产品中高达三倍的霉菌毒素对动物健康有不利影响。因而有必要在玉米发酵时灭活或去除黄曲霉毒素。之前发现蒙脱石能高效吸附乙醇和葡萄糖溶液中的黄曲霉毒素B1，而乙醇和葡萄糖是玉米发酵液中的两种主要化合物。本研主要目的是评估在真正的玉米发酵液中，蒙脱石吸附黄曲霉毒素B1的效率。其次是识别任何可能妨碍黄曲霉毒素B1吸附的干扰化合物。研究表明发酵液中的化合物，最有可能是蛋白质，对蒙脱石吸附黄曲霉毒素B1的干扰很大。但是，尽管干扰很大，吸附试验表明蒙脱石在一定程度上仍能吸附黄曲霉毒素B1。处理发酵液的蒙脱石在~1595、1383、1362、1304、1272和1205cm− 1出现特异性黄曲霉毒素B1条带，表明粘土矿物中存在霉菌毒素。还要采取措施提高蒙脱石对玉米发酵液中黄曲霉毒素的选择性。
外文摘要：Corn is the main feedstock used for ethanol production in the United States. To reduce wastage and toxicity to human and animal, using aflatoxin contaminated corn in biofuel industry is thought to be rational. Yet up to three-fold of increment of the mycotoxins in the co-product have detrimental impact on animal health. It would be desirable to inactivate or to remove aflatoxins during fermentation of corn. Smectites were previously found to be highly efficient for aflatoxin B1 adsorption in ethanol and glucose solution, two major compounds in corn fermentation solution. The primary objective of the present study was to evaluate the aflatoxin B1 adsorption efficiency by smectites in real corn fermentation solution. The secondary objective was to identify any interfering compound that might hinder aflatoxin B1 adsorption. Aflatoxin B1 adsorption by smectites in fermentation solution was found to be low. A calcium smectite (3MS) had aflatoxin B1 adsorption capacity (Qmax) of 0.22 mol kg− 1 in the fermentation solution but 0.54 mol kg− 1 in the aqueous solution. The Fourier transform infrared (FTIR) analyses indicated that some compounds from fermentation solution were adsorbed on the smectites and had irreversible bonding with the clay minerals. Those compounds competed with aflatoxin B1 for the adsorbing sites of smectites. The major infrared bands due to interfering compounds were at ~ 1653, 1532, 1451, and 1235 cm− 1. These bands appeared when smectites were added to either clean or aflatoxin B1 spiked fermentation solutions. Similar spectral bands were obtained after treating the smectites with zein, a major protein in corn. Thus, the major interfering compounds in fermentation solution were believed to be proteins. The XRD results proved the adsorption of the proteins in the interlayer of smectites. After heating at 300 °C, smectites reacted with fermentation solution had d-spacing of at least 15 Å, whereas the pure smectites collapsed to ~ 10 Å. This reflected great interferences of the compounds, most possibly proteins on aflatoxin B1 adsorption by the smectites. However, despite of strong interferences, adsorption experiments suggested that smectites were still able to adsorb aflatoxin B1 to some extent. Presence of characteristic aflatoxin B1 bands at ~ 1595, 1383, 1362, 1304, 1272, and 1205 cm− 1 on smectite complexes treated in fermentation solution revealed the existence of the mycotoxins on the clay minerals. Strategies should be taken to enhance the selectivity of smectites for the aflatoxins in corn fermentation solution.
外文关键词：Aflatoxin B-1；Smectite；Fermentation solution；Zein, Protein
作者：Alam, SS；Deng, YJ
作者单位：Texas A&M Univ
期刊名称：APPLIED CLAY SCIENCE
期刊影响因子：2.586
出版年份：2017
出版刊次：8
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