Identification of mouldy rice using an electronic nose combined with SPME-GC/MS

Early warning of mildew in grain storage is extremely important to ensure the security of reserves. Japonica rice (Oryza sativa subspecies. Japonica) was used as an example in this study to develop a strategy for the establishment of an early warning and analysis system for grain mildew, that is, an electronic nose (E-nose) is used to analyse the volatile substances produced during the mildewing of japonica rice. The main volatile components of mildewed japonica rice were determined to be alcohol, aldehyde and ketone, to which the W2S sensor of the E-nose is sensitive. A gas chromatography-mass spectrometry (GC-MS) analysis showed that the content of mouldy markers (1-octen-3-ol and 3-octanone) and the response of the W2S sensor were highly correlated with the total colony number. Principal component analysis (PCA) and cluster analysis further verified the excellent performance of the E-nose in identifying japonica rice mildewing. Thus, it is feasible to use the E-nose in combination with GC/MS for the early detection of mould contamination of japonica rice.