Abstract: In this study, headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was employed for the analysis of volatile substances in healthy potatoes and those with different degrees of dry rot (light, moderate and heavy). The results showed that 43 volatile components were identified, including 18 aldehydes, 9 alcohols, 5 ketones, 5 alkenes, 2 esters, 2 amines, 1 furan and 1 ether. The contents of octene, α-carcelene, cyclohexanone, heptyl aldehyde and acetaldehyde went up with increasing severity of dry rot, and dipropyl disulfide, styrene, isobutanol and nonenal were produced in samples with heavy soft rot as the specific volatile components related to metabolites of Fusarium sambucinum. Fingerprints were developed that allowed to visually discern the differences in volatile components between samples with different degrees of rot severity. Principal component analysis (PCA) showed that the healthy and rotten potatoes could be effectively distinguished based on volatile components. We concluded that HS-GC-IMS allows visual comprehensive identification of the differences in volatile components between potatoes with different degrees of rot severity and effective identification of the specific volatile components of potatoes with dry rot, which can provide the theoretical basis for the diagnosis and identification of dry rot in potatoes based on odor sensing information.

Key words: potato; dry rot; headspace-gas chromatography-ion mobility spectrometry; principal component analysis; fingerprint