Multi-spectral kernel sorting to reduce aflatoxins and fumonisins in Kenyan maize
Multi-spectral kernel sorting to reduce aflatoxins and fumonisins in Kenyan maize
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DOI：
10.1016/j.foodcont.2017.02.038
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发表时间：
2017-08-01
期刊：
影响因子：
6
通讯作者：
Nelson, Rebecca J.
中科院分区：
文献类型：
--
作者：
Stasiewicz, Matthew J.;Falade, Titilayo D. O.;Nelson, Rebecca J.
玉米是包括肯尼亚在内的许多非洲国家的主食，经常受到黄曲霉毒素和伏马菌素等有毒和致癌真菌次生代谢物的污染。这项研究评估了一种低成本、多光谱分选机在鉴定和去除大量成熟玉米籽粒中受黄曲霉毒素和伏马菌素污染的单粒籽粒的潜在用途。通过建立一个数学模型，将9个不同波长(470-1550 nm)的反射率与从露天市场小规模玉米贸易商和肯尼亚东部接种玉米田间试验中收集的单粒玉米的真菌毒素水平联系起来，对该机器进行了校准。由于预期霉菌毒素污染的偏斜分布，对可能的危险因素，如变色、霉变、破损和紫外光(365 Nm)下的荧光进行了目测评估，以丰富用于校准的霉菌毒素阳性核。使用红外和可见光光谱的判别分析校准分别获得了77%的灵敏度和83%的特异度来识别黄曲霉毒素10ngg(-1)和伏马菌素1000ngg(-1)(通过ELISA法或UHPLC法测量)。在随后对46个之前检测真菌毒素的市场玉米样品进行分选时，以前检测毒素阳性的样品拒绝了0-25%的样品，之前毒素阴性的样品拒绝了0-1%的样品。在大多数情况下，在分拣的玉米流中检测到真菌毒素，接受的玉米的霉菌毒素水平低于拒绝的玉米(21/25接受的玉米流的黄曲霉毒素低于拒绝的流，25/27接受的玉米流的伏马菌素低于拒绝的流)。减少具有统计学意义(p<；0.001)，每种毒素平均减少83%。随着进一步的发展，这项技术可以用来在当地的锤子磨坊分拣玉米，以减少肯尼亚和世界其他地方的人类真菌毒素暴露，同时立即减少食品损失，改善食品安全和营养状况。(C)2017爱思唯尔有限公司。保留所有权利。
Maize, a staple food in many African countries including Kenya, is often contaminated by toxic and carcinogenic fungal secondary metabolites such as aflatoxins and fumonisins. This study evaluated the potential use of a low-cost, multi-spectral sorter in identification and removal of aflatoxin- and fumonisin-contaminated single kernels from a bulk of mature maize kernels. The machine was calibrated by building a mathematical model relating reflectance at nine distinct wavelengths (470-1550 nm) to mycotoxin levels of single kernels collected from small-scale maize traders in open-air markets and from inoculated maize field trials in Eastern Kenya. Due to the expected skewed distribution of mycotoxin contamination, visual assessment of putative risk factors such as discoloration, moldiness, breakage, and fluorescence under ultra-violet light (365 nm), was used to enrich for mycotoxin-positive kernels used for calibration. Discriminant analysis calibration using both infrared and visible spectra achieved 77% sensitivity and 83% specificity to identify kernels with aflatoxin >10 ng g(-1) and fumonisin >1000 ng g(-1), respectively (measured by ELISA or UHPLC). In subsequent sorting of 46 market maize samples previously tested for mycotoxins, 0-25% of sample mass was rejected from samples that previously tested toxin-positive and 0-1% was rejected for previously toxin-negative samples. In most cases where mycotoxins were detected in sorted maize streams, accepted maize had lower mycotoxin levels than the rejected maize (21/25 accepted maize streams had lower aflatoxin than rejected streams, 25/27 accepted maize streams had lower fumonisin than rejected streams). Reduction was statistically significant (p < 0.001), achieving an 83% mean reduction in each toxin. With further development, this technology could be used to sort maize at local hammer mills to reduce human mycotoxin exposure in Kenya, and elsewhere in the world, while at once reducing food loss, and improving food safety and nutritional status. (C) 2017 Elsevier Ltd. All rights reserved.