Rapid analysis of volatile biomarkers: Application of real-time mass spectrometry for the detection of insect infestation in brown rice

Abstract

To prevent serious insect infestation in stored food, the development of early insect detection methods is essential. At present, detection is primarily conducted using pheromone traps, which are effective only after the insects have already propagated. In our previous study, new volatile biomarkers for the detection of insects in brown rice were determined using gas chromatography-mass spectrometry (GC-MS). In the present study, we attempted to develop a rapid analytical approach for the detection of major volatile biomarkers emitted from brown rice infested with Indian meal moth, rice moth, and maize weevil by employing a real-time mass spectrometry known as selected ion flow tube mass spectrometry (SIFT-MS). With selected ion monitoring (SIM) of m/z 86 by NO+ ionization, product ions that corresponded to prenol and isoprenol were detected from Indian meal moth-infested and rice moth-infested brown rice. The compounds were easily distinguishable from each other according to whether prenol-parallel prenal was generated. In the case of maize weevil, the target dimethyl trisulfide (DMTS) fluctuated at low levels. Nonetheless, the characteristic principal component analysis (PCA) score for maize weevil-infested brown rice could be obtained using the observed full scan data.