Occurrence and impact of carbendazim and hymexazol residues on yeast and ochratoxin A contamination during wine production.

Abstract

Grapes are vulnerable to carbon black aspergilli, which can produce the mycotoxin, Ochratoxin A (OTA). Carbendazim and hymexazol, are widely applied to control grape diseases. Fungicides, toxigenic fungus and OTA can be transferred from grapes to wine causing potential safety issues. But during the vinification, the impact of these residues per fungal populations and OTA are currently unclear. Here we investigated the effects of carbendazim and hymexazol on viability of A. carbonarius and OTA contamination during an indoor wine processing experiment. The population size of A. carbonarius substantially increased at 24 h then significantly decreased at 72 h after destemming and crushing, but carbendazim and hymexazol notably inhibited the amounts of A. carbonarius in must samples. Yeast growth was substantially slowed by carbendazim, hymexazol, and OTA during the first 3 d compared with the control. Carbendazim, hymexazol and OTA residues declined over time, and the processing factors for carbendazim and hymexazol throughout vinification were 0.164, 0.074 and 0.185-0.476, respectively. In addition, carbendazim and hymexazol individually reduced OTA concentrations. However, there was no significant difference after 48 h. Addition of carbendazim or hymexazol significantly reduced the level of A. carbonarius while had no significant effect on the final concentration of OTA in mature wine. While the wine-making process can reduce the residues of OTA, carbendazim and hymexazol in grapes, it is recommended to choose grapes that are free of A. carbonarius contamination to make wine. This article is protected by copyright. All rights reserved.