Volatile organic compounds of <i>Hanseniaspora uvarum</i> increase strawberry fruit flavor and defense during cold storage

Abstract

Volatile organic compounds (VOCs) of antagonistic yeasts are considered as environmental safe fumigants to promote the resistance and quality of strawberry (<i>Fragari</i>a <i>ananassa</i>). By GC-MS assays, VOCs of <i>Hanseniaspora uvarum</i> (<i>H. uvarum</i>) fumigated strawberry fruit showed increased contents of methyl caproate (5.8%), methyl octanoate (5.1%), and methyl caprylate (10.9%) in postharvest cold storage. Possible mechanisms of <i>H. uvarum</i> VOCs involved in regulations of the defense-related enzymes and substances in strawberry were investigated during postharvest storage in low temperature and high humidity (2 ± 1°C, RH 90%-95%). Defense-related enzymes assays indicated <i>H. uvarum</i> VOCs stimulated the accumulation of CAT, SOD, POD, APX, PPO, and PAL and inhibited biosynthesis of MDA in strawberry fruit under storage condition. Moreover, the expression levels of related key enzyme genes, such as <i>CAT</i>, <i>SOD</i>, <i>APX42</i>, <i>PPO</i>, and <i>PAL6</i>, were consistently increased in strawberry fruit after <i>H. uvarum</i> VOCs fumigation.