The dynamic and diverse volatile profiles provide new insight into the infective characteristics of Penicillium expansum in postharvest fruit

Abstract

Penicillium expansum causes postharvest disease, fruit loss and patulin (PAT) accumulation in a broad host range and is responsible for considerable health risks and economic losses. In this study, the dynamic volatile organic compounds (VOCs), fungal growth, and PAT accumulation were investigated in apple, pear, citrus and tomato. These indicators revealed the response specificity of fruit to P. expansum attack. PAT content ranged from 2.54 mg/kg to 4.48 mg/kg, while the highest accumulation was detected in citrus. A total of 247 VOCs were identified using GC-IMS and HS-SPME-GC/MS, esters were the most abundant components, followed by alcohols, aldehydes, and ketones. OPLS-DA analysis revealed that the different infection stages were classified successfully. Furthermore, 21, 23, 19, 34 VOCs from each fruit showed significant correlations with PAT accumulation, respectively. Isovaleric acid and 1-hexanol were identified as potential biomarkers in all the fruit. Taken together, P. expansum inoculation caused decay and PAT accumulation in fruit under suitable conditions, leading to a change in VOCs during storage and release of specific volatiles. The present work lays the foundations for studying the interaction mechanism between P. expansum and host, as well as early detection of P. expansum infection and PAT accumulation in postharvest fruit.