欧亚国际

国外科学家刚刚利用Videometer多光谱成像系统发表了题为“Combination of DNA barcoding, targeted metabolite profiling and multispectral imaging to identify mold species and metabolites in sliced bread”的文章，文章发表于期刊Future Foods上。

结合DNA条形码、靶向代谢物分析和多光谱成像来识别切片面包中的霉菌种类和代谢物

热点

DNA条形码鉴定霉菌种类

通过靶向代谢物分析确认已识别物种

多光谱成像对霉斑的可视化

处理发霉面包的建议

摘要

霉菌是普遍威胁安全食品的因素。在这项工作中，提出了三种可靠方法的组合，用于在物种水平上识别食品中存在的霉菌，以评估表面上不发霉的面包片的安全性，从而有助于防止食物浪费。在储藏过多的切片面包中，通过DNA条形码鉴定出第一层面包上的三种霉菌（球毛壳菌、产黄青霉和短尾帚霉）。获得的PCR产物序列在BLAST比对中100%匹配，e值为0。靶向代谢物分析证实了真菌毒素产生菌球毛壳菌和产黄青霉素的存在。对这些霉菌的已知真菌毒素（分别为球毛壳霉素A和黑色素）在面包斑点A中进行了定量（8.2微克/克球毛菌素A和2.2微克/g黑色素）。第二片感染较少，仅由两个霉点显示，在多光谱成像后，通过归一化典型判别分析（nCDA）测定的霉菌代谢物数量较低。在堆栈的第三层上，通过代谢物分析或比较多光谱成像未检测到霉菌痕迹。这些结果表明，在面包堆的下层食用面包片可能是安全的，即使在面包片的外层可以看到霉菌生长。

关键词：霉菌、毒素代谢组学、食品安全、主食、食品废弃物

缩写:聚合酶链反应（PCR）、内转录间隔区rDNA、（ITS）大亚基（LSU）、小亚基（SSU）、归一化标准判别分析（nCDA）

Combination of DNA barcoding, targeted metabolite profiling and multispectral imaging to identify mold species and metabolites in sliced bread

Highlights

Identification of mold species by DNA barcoding

Confirmation of identified species by targeted metabolite profiling

Visualization of moldy spots by multispectral imaging

Recommendations for the disposal of moldy bread should possibly be reconsidered

Abstract

Mould is a ubiquitous threat to safe food. In this work, a combination of three reliable methods to identify mould present in food at the species level is presented, to estimate the safety of the apparently non-moldy slices of bread and therefore contribute to the prevention of food waste. In overstored sliced bread, three mould species on the first slice of the stack (Chaetomium globosum, Penicillium chrysogenum and Scopulariopsis brevicaulis) were identified by DNA barcoding. The obtained sequences of the PCR products matched 100% in BLAST alignments with an e-value of 0. Targeted metabolite profiling confirmed the presence of the mycotoxin producers Chaetomium globosum and Penicillium chrysogenum. Known mycotoxins from these moulds (chaetoglobosin A and meleangrin, respectively) were quantitated (8.2 µg/g chaetoglobosin A and 2.2 µg/g meleangrin) in bread spot A. The second slice was less infected, which was revealed by only two mouldy spots, the lower amounts of determined mould metabolites and by normalized canonical discriminant analysis (nCDA) after multispectral imaging. On the third slice of the stack, no mould traces were detected by either metabolite profiling, or comparative multispectral imaging. These results suggest that it might be safe to consume bread slices in lower layers of bread stacks, even if mould growth is visible on the outer slices.

Keywords Mycotoxin metabolomics,food safety,staple food,food waste

Abbreviations Polymerase Chain Reaction(PCR),internal transcribed spacer rDNA,(ITS) large subunit(LSU),small subunit(SSU),normalized canonical discriminant analysis (nCDA)