LAUSR

BACKGROUND Citrus 'Benimadonna' (Citrus reticulata × Citrus sinensis), as a high-value perishable fruit, there is an urgent demand for preservation technology with high effectiveness and low safety risk from industries. Nα-lauroyl-L-arginine ethyl ester hydrochloride (LAE) was applied to enhance the preservability of by compounding with natamycin, and the possible fungal inhibition mechanism based on the hypothesis of impact on membrane by surfactant was investigated. RESULTS In vitro test showed the minimum inhibitory concentration of LAE against Penicillium expansum (PE), isolated as the predominant spoilage inducing fungus, was 32 mg/L and it was partially synergistic with natamycin. Afterward, in vivo test proved the inhibition capacity. In 90 days' refrigerated preservation, spoilage rate was decreased by preharvest spraying significantly versus control without extra taste loss, and LAE showed an alleviating benefit on total pectin loss. Subsequently, electron microscopic imaging and intracellular protein levels of PE exposed in LAE indicated that, LAE stress lead to the increased permeability and decreased cell integrity. Moreover, peroxidase, superoxide dismutase and catalase revealed that LAE enhanced oxidative stress while pectinase was antagonized. CONCLUSION The present investigation firstly introduced LAE as a candidate active ingredient for citrus preservative. A theoretical basis was provided for the development of preservation technology for high-value perishable fruit. According to the authors' knowledge this study is the first report about the inhibition mechanism of LAE in terms of oxidative stress. This article is protected by copyright. All rights reserved.