Early detection and monitoring for Aspergillus flavus contamination in maize kernels

Aspergillus flavus is one of the pathogens that can cause massive losses in the maize industry during the postharvest and storage stages. However, the methods for rapid and sensitive detection of early A. flavus contamination are still lacking. The aim of this study is to evaluate the performance of volatile organic compounds (VOCs) in evolution monitoring and early detection of A. flavus contamination in maize kernels. We successfully applied headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) to evaluate changes of VOCs in maize kernels caused by A. flavus contamination. A total of 55 VOCs were identified in maize kernels contaminated with A. flavus. Heat map and principal component analysis (PCA) analysis showed that ethyl acetate-D and 3-hydroxybutan-2-one-D are potential biomarkers specific to A. flavus contamination in maize kernels. Aflatoxin B1 (AFB1) is positively correlated with the level of (E)-2-octenal-M, benzene acetaldehyde, (E)-hept-2-enal-M, 2-heptanone-D, and 2-pentyl furan. These results provide potential targets for the development of sensors to evaluate the early mold contamination in stored maize kernels.