Responses of Fresh-Cut Strawberries to Ethanol Vapor Pretreatment: Improved Quality Maintenance and Associated Antioxidant Metabolism in Gene Expression and Enzyme Activity Levels.

Strawberries were treated with different concentrations of ethanol vapor and then cut into four wedges and stored at 4 °C for 1 week. It was found that 4 mL/kg of ethanol was the optimal concentration to reduce the decrease of firmness and weight loss. Total phenolics content, total flavonoid and anthocyanin contents, antioxidant enzyme activities, and gene expression related to the antioxidant were elevated using the ethanol treatment. Ethanol vapor also suppressed microbial growth and promoted free radical (hydroxyl and DPPH) scavenging capacities and four kinds of esters and bioactive components in strawberry wedges. Moreover, ethanol enhanced antioxidant enzyme activities including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) by activating related gene expression. The results of our research indicate that ethanol vapor has potential application in preserving quality and improving antioxidant capacity of fresh-cut strawberries.