The dynamics of ochratoxigenic fungi contents through different stages of dried grape production

Abstract

Dried vine fruit (raisin, sultana and currant) is the second (after wine) most important product of viticulture. Concerning this, the contamination of dried grape by ochratoxigenic fungi and ochratoxin A (OTA) has attracted much attention. Favorable climatic conditions in countries with well-developed viticulture contribute to the spreading of ochratoxigenic fungi. The aim of this work was to identify the contamination sources of dried vine fruit by ochratoxigenic filamentous fungi and OTA, as well to determine the Critical Control Points (CCP) at different stages of production. Primary contamination of grapes occurred during vegetation, especially maturation period, when the risk of mechanical damages was the highest one. 48 samples of soil and 81 samples of fresh grape berries collected in 4 regions of Armenia were investigated. As a result, 22 micromycetes sp. from 7 genera were isolated. Drying process is one of the main CCP. As the most of dried products is produced by open sun drying method, secondary contamination occurs in plants. In our studies 27 species of filamentous fungi were revealed in 87 samples of dried vine fruit, collected at different stages of production. The samples had quite high contamination level by potential toxigenic A. niger and A. carbonarius species.