Influence of physical and chemical characteristics of wine grapes on the incidence of Penicillium and Aspergillus fungi in grapes and ochratoxin A in wines

Abstract

The incidence of filamentous fungi and toxin levels in grapes and wines varies depending on the variety of grapes, the wine region, agricultural practices, weather conditions, the harvest and the winemaking process. In this sense, the objective of this study was to evaluate the diversity of Aspergillus and Penicillium fungi isolated from wine grapes of the semi-arid tropical region of Brazil, evaluate the presence of ochratoxin A (OTA) in the experimental wine and verify if there is a correlation between occurrence of these fungi and the physicochemical characteristics of the wine grapes grown in the region. For the isolation of fungi we used the direct plating technique. The presence of OTA in the experimental wine was detected by high-performance liquid chromatography. The species found were Aspergillus niger, A. carbonarius, A. aculeatus, A. niger Aggregate, A. flavus, A. sojae, Penicillium sclerotiorum, P. citrinum, P. glabrum, P. decumbens, P. solitum and P. implicatum. All isolates of A. carbonarius were OTA producers and all P. citrinum were citrinin producers. The highest concentration of OTA was found in red wine (0.29μg/L). All species identified in this study, except A. flavus, showed a positive correlation with at least one physicochemical parameter assessed, highlighting the pectin content, total sugar, total acidity and phenolic compounds.

A quantitative study on growth variability and production of ochratoxin A and its derivatives by A. carbonarius and A. niger in grape-based medium

“…Although all strains were isolated from wine grapes cultivated in the tropical semi-arid region of Brazil, strains 10614 and 10625, the largest producers of OTA, were the only strains isolated from the region of Casa Nova-BA, Brazil. These data demonstrate that, in addition to geographic influence over the strain variability and variation of species isolated from grapes, there is also the influence of the microclimate of each region 2 . Moreover, genetic and phenotypic factors will also influence the production of secondary metabolites by strains within the same species 20 , 29 .…”

“…Among the filamentous fungi detected in grapes, these species are the most commonly found, accounting for up to 98.5% of fungi of the Aspergillus genus isolated from grapes 1 . Although the detection of A. carbonarius has a lower incidence in grapes, this species is highly relevant for risk analysis, since it produces higher levels of OTA when compared to A. niger 2 – 4 , 31 . Moreover, it is possible that strains of the A. carbonarius species were adapted to the grape-based culture medium differently than strains of A. niger , and therefore, higher levels of OTA were detected.…”

“…The mycotoxigenic fungi most often associated with this context are from the Aspergillus genus, with A. niger and A. carbonarius figuring as the most relevant species. In addition to deteriorating the food product, these species are also responsible for the production of ochratoxin A (OTA), the main mycotoxin detected in grapes and derivatives (wine and juice) 1 , 2 . A. carbonarius is less common in grapes when compared to A. niger species; nonetheless, they are more relevant due to the increased proportion of high-level OTA-producing isolates, which are the ones responsible for the accumulation of OTA in grapes and derivatives 3 , 4 .…”

An indigenousSaccharomyces uvarumpopulation with high genetic diversity dominates uninoculated Chardonnay fermentations at a Canadian winery

“…The presence of Apergillus and Penicillium spp. in food, including grape must, has been observed previously [12,44,68]. These fungi have the potential to produce mycotoxins, which can be dangerous if consumed in large quantities [69,70].…”

Simultaneous Analysis of 20 Mycotoxins in Grapes and Wines from Hexi Corridor Region (China): Based on a QuEChERS–UHPLC–MS/MS Method

“…Grapes are vulnerable to be affected by various types of fungal, and the toxinogenic fungi can produce mycotoxins [ 2 ]. Previous studies indicated that there was a correlation between physiochemical qualities of wine grapes and the presence of all isolated fungi [ 3 ]. Although sophisticated treatment has been applied in the process of grape planting and wine making, fungal contamination is still unavoidable.…”