Comprehensive dynamic analysis of potential volatile biomarkers emitted by three fungi contamination on kiwifruit soft rot utilizing HS–SPME/GC–MS: An early monitoring and warning strategy

Kiwifruit with various nutrients and pleasing flavor is highly susceptible to soft rot diseases during postharvest storage, resulting in serious economic losses and ecological contamination. Nevertheless, the methods for rapid, sensitive, timely and accurate detection of soft rot contamination on kiwifruit remain poorly developed. This study aims to put forward a strategy for identification and warning of soft rot contamination in kiwifruit on the basis of volatile biomarkers. Headspace–solid phase micro extraction/gas chromatography–mass spectrometry (HS–SPME/GC–MS) were utilized to determine volatile organic compounds (VOCs) of soft rot contamination in kiwifruit by pathogenic fungi, such as B. dothidea, Diaporthe spp., A. alternata. Compared to a total of 61 VOCs detected in uncontaminated kiwifruit, more volatiles were emitted in three fungal infected kiwifruits throughout storage for 7 days, including 96, 95 and 96 VOCs, separately. During the decay period, the proportion of aldehydes contents decreased significantly from approximately 90 % in first 3 days to 31.77 %, 0.92 %, 26.07 % at the 7th day in three fungal infected kiwifruits, separately. Alcohols contents in three fungal infected kiwifruits increased, accounting for a greater proportion of 27.31 %, 66.47 % and 37.25 % at the 7th day, respectively. Additionally, esters contents in B. dothidea and A. alternata and alkenes in Diaporthe spp. infected kiwifruit also increased. Fifteen potential volatile biomarkers from three fungal infected kiwifruits were screened and identified in aerial in whole kiwifruit treatment groups, such as phenylethyl alcohol, 4-carene, ethanol, etc. These findings provide the feasibility and application potential of volatile biomarkers for targeted and precise identification of soft rot occurrence in postharvest kiwifruit.