Incidência de ocratoxina A em vinhos e a correlação de fungos do gênero Aspergillus e Penicillium com as características físicoquímicas de uvas viníferas da região tropical semiárida do Brasil
Year: 2016
Type: dissertation
Abstract: Grapes (Vitis vinifera L.) are subject to contamination by filamentous \nfungi present in crops, during harvest and winemaking, Aspergillus being the \nmain producing genus of ochratoxin A (OTA) in grapes. The incidence of fungi \nand toxin levels vary depending on the variety of grapes, the winemaking region, \nagricultural practices, weather conditions, harvest and the winemaking process. \nThus, this study aimed to evaluate the diversity of Aspergillus and Penicillium \nfungi isolated from the grapes and the cultivation soil in the São Francisco \nSubmidle Valley winegrowing region, the presence of OTA in experimental \nwines, as well as if there is a correlation between the occurrence of Aspergillus \nand Penicillium fungi and the physicochemical characteristics of the wine grapes \ngrown in the region. Samples of grapes and soil from the vineyards were \ncollected from the 2/2014 and 1/2015 crops. For the isolation of filamentous \nfungi from the grape berries, the direct plating technique in DRBC culture \nmedium was used. For soil samples the surface-spreading technique in DG-18 \nmedium was used. The Aspergillus and Penicillium species were identified by \nmorphological characteristics and the presence of OTA in experimental wines \nwas detected by HPLC. The physicochemical characterization of the grapes was \nalso performed. Contamination of vineyard soil ranged from 2.34 x 10³CFU/g to \n4.35 x 104CFU /g. The species found in the wine grapes were Aspergillus niger, \nA. carbonarius, A. aculeatus, A. niger Aggregate, A. flavus, A. sojae, Penicillium \nsclerotiorum, P. citrinum, P. glabrum, P. decumbens, P. implicatum and P. \nsolitum. All of A. carbonarius isolates, 18.18% of A. niger, 14.29% of A. niger \nAggregate and 60% of A. ochraceus were OTA-producing fungi. All A. \nparasiticus were producers of B1, B2, G1 and G2 aflatoxins, whereas only 14% \nof A. flavus were producers of B1, B2 aflatoxin. All P. citrinum were citrinin \nproducers. The highest OTA concentration was found in red wine (0.29μg / L) \nand in white wines it ranged from 0.02 to 0.04μg / L. All identified species in \nthis study showed a positive correlation with at least one evaluated \nphysicochemical parameter, highlighting the pectin content, total sugar, total \nacidity and phenolic compounds. It was observed that the fungi incidence and \nOTA levels vary according to the variety of grapes, cultivation methods, weather \nconditions and crop.
Author: Freire, Luisa
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2278687365