Mycobiota of Czech wine grapes and occurrence of ochratoxin A and Alternaria mycotoxins in fresh grape juice, must and wine.

2007 ◽  
Vol 59 (2) ◽  
pp. 241-254 ◽  
Author(s):  
Vladimír Ostrý ◽  
Jarmila Škarková ◽  
Ivana Procházková ◽  
Alena Kubátová ◽  
František Malíř ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Grape Juice ◽  
Wine Grapes ◽  
Alternaria Mycotoxins

Impact of Water Activity and Temperature on Growth and Ochratoxin A Production of Two Aspergillus carbonarius Isolates from Wine Grapes in Greece

2007 ◽  
Vol 70 (12) ◽  
pp. 2884-2888 ◽  
Author(s):  
CHRYSOULA C. TASSOU ◽  
PANTELIS I. NATSKOULIS ◽  
EFSTATHIOS Z. PANAGOU ◽  
APOSTOLOS E. SPIROPOULOS ◽  
NARESH MAGAN
Keyword(s):  
Ochratoxin A ◽  
Water Activity ◽  
Color Change ◽  
Fungal Growth ◽  
Grape Juice ◽  
Lag Phase ◽  
Aspergillus Carbonarius ◽  
Wine Grapes ◽  
Wine Production

The aim of this study was to determine the effects of water activity (aw; 0.85 to 0.98) and temperature (10 to 40°C) on the radial growth rate and ochratoxin A (OA) production of two Aspergillus carbonarius isolates in vitro. The isolates were obtained from wine grapes cultivated in Greece, and the trial was conducted with a synthetic grape juice medium similar in composition to grapes between veraison (beginning of color change) and ripeness. Fungal growth and OA production data were collected for 55 days. Response surface curves and cardinal values for aw and temperature were obtained using multiple regression analysis. The lag phase lasted from less than 1 to 10 days. Both isolates grew optimally at 30 to 35°C and 0.96 aw, but maximum OA production occurred under suboptimal growth conditions (15 to 20°C and 0.93 to 0.96 aw). Growth also was observed at 0.85 aw and 25°C, however at this same aw the fungus failed to produce mycelium at any other temperatures tested. The isolates produced OA at 15 to 30°C and 0.90 to 0.98 aw. Maximum OA production was detected after 25 days of incubation at 20°C and 0.96 aw and was 3.14 and 2.67 μgg−1, respectively, for the two strains. The isolated strains used in this study were more xerotolerant than others from the Mediterranean basin. These data will allow producers to identify and thus monitor critical environmental conditions effectively in wine grapes. These data also increase the knowledge base concerning the ability of A. carbonarius to grow and produce toxin under different ecological conditions and can contribute to the development of secondary models for the prediction and risk assessment of OA in wine production.

scholarly journals Comparison of Flow Injection-MS/MS and LC-MS/MS for the Determination of Ochratoxin A

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 547
Author(s):  
Kai Zhang
Keyword(s):  
Ochratoxin A ◽  
Flow Injection ◽  
Internal Standard ◽  
Grape Juice ◽  
Tandem Mass ◽  
Triple Quadrupole ◽  
On Line ◽  
Red Grape Juice ◽  
Red Grape

Two methods for measuring ochratoxin A in corn, oat, and grape juice were developed and compared. Flow injection (FI) and on-line liquid chromatography (LC) performances were evaluated separately, with both methods using a triple quadrupole tandem mass spectrometer (MS/MS) for quantitation. Samples were fortified with 13C uniformly labeled ochratoxin A as the internal standard (13C-IS) and prepared by dilution and filtration, followed by FI- and LC-MS/MS analysis. For the LC-MS/MS method, which had a 10 min run time/sample, recoveries of ochratoxin A fortified at 1, 5, 20, and 100 ppb in corn, oat, red grape juice, and white grape juice ranged from 100% to 117% with RSDs < 9%. The analysis time of the FI-MS/MS method was <60 s/sample, however, the method could not detect ochratoxin A at the lowest fortification concentration, 1 ppb, in all tested matrix sources. At 5, 20, and 100 ppb, recoveries by FI-MS/MS ranged from 79 to 117% with RSDs < 15%. The FI-MS/MS method also had ~5× higher solvent and matrix-dependent instrument detection limits (0.12–0.35 ppb) compared to the LC-MS/MS method (0.02–0.06 ppb). In the analysis of incurred corn and oat samples, both methods generated comparable results within ±20% of reference values, however, the FI-MS/MS method failed to determine ochratoxin A in two incurred wheat flour samples due to co-eluted interferences due to the lack of chromatographic separation.

Adsorption of ochratoxin A from grape juice by yeast cells immobilised in calcium alginate beads

2016 ◽  
Vol 217 ◽  
pp. 29-34 ◽  
Author(s):  
Maria Grazia Farbo ◽  
Pietro Paolo Urgeghe ◽  
Stefano Fiori ◽  
Salvatore Marceddu ◽  
Samir Jaoua ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Calcium Alginate ◽  
Grape Juice ◽  
Alginate Beads ◽  
Yeast Cells ◽  
Calcium Alginate Beads

Current Importance of Ochratoxin A–Producing Aspergillus spp.

2001 ◽  
Vol 64 (6) ◽  
pp. 903-906 ◽  
Author(s):  
M. L. ABARCA ◽  
F. ACCENSI ◽  
M. R. BRAGULAT ◽  
F. J. CABAÑES
Keyword(s):  
Ochratoxin A ◽  
Animal Health ◽  
Grape Juice ◽  
Poultry Meat ◽  
Aspergillus Ochraceus ◽  
Aspergillus Carbonarius ◽  
Penicillium Verrucosum ◽  
Closely Related Species ◽  
High Incidence ◽  
Food Commodities

Ochratoxin A (OA) is receiving attention worldwide because of the hazard it poses to human and animal health. OA contamination of commodities, such as cereals or pork and poultry meat, is well recognized. Nevertheless, there is an increasing number of articles reporting OA contamination in other food commodities, such as coffee, beer, wine, grape juice, and milk, in the last few years. This continuous and increasing exposure to OA that humans experience is reflected in the high incidence of OA in both human blood and milk in several countries. OA was believed to be produced only by Aspergillus ochraceus and closely related species of section Circumdati and by Penicillium verrucosum; however, in the genus Aspergillus, the production of OA has been recently reported by species outside the section Circumdati. Thus, it has been clearly established as a metabolite of different species of the section Nigri, such as Aspergillus niger and Aspergillus carbonarius. OA production ability by Aspergillus spp. is more widespread than previously thought; therefore, there is the possibility that unexpected species can be new sources of this mycotoxin in their natural substrates.

scholarly journals Rapid Determination of Ochratoxin A in Grape and Its Commodities Based on a Label-Free Impedimetric Aptasensor Constructed by Layer-by-Layer Self-Assembly

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 71 ◽  
Author(s):  
Mina Nan ◽  
Yang Bi ◽  
Huali Xue ◽  
Sulin Xue ◽  
Haitao Long ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Self Assembly ◽  
Electrochemical Impedance ◽  
Rapid Determination ◽  
Grape Juice ◽  
High Sensitivity ◽  
Layer By Layer ◽  
Label Free ◽  
Transfer Resistance

A simple and sensitive label-free impedimetric aptasensor for rapid determination of ochratoxin A (OTA) has been developed, which was based on the combination between thiolated aptamer and gold nanoparticles by layer-by-layer self-assembly. Because of the interaction between aptamer and OTA, the relative normalized electron-transfer resistance (ΔRct) values obtained by electrochemical impedance spectroscopy (EIS) was proportional to the concentration of OTA and showed a good linear relationship from 0.1 to 10.0 ng/mL, with a lower detection limit (0.030 ng/mL) than one-step thiolated DNA aptasensor. The established method was successfully applied to detect and analyze OTA in table wine and grape juice, and the recovery was 90.56%–104.21% when PVP effective removed of phenolic substances. The label-free impedimetric aptasensor was used for rapid detection and quantitation of OTA in the inoculated grapes with the Aspergillus Nigri (H1), and the production of OTA (62.4 μg/kg, 20 μg/kg) far exceeded the maximum levels of 2 μg/kg after inoculation for three days. The developed method exhibited a good specificity, high sensitivity, time-efficient, and it could be applied to detect the OTA concentration in grape and its commodities.

Ochratoxin A-producing fungi in Spanish wine grapes and their relationship with meteorological conditions

2005 ◽  
Vol 113 (3) ◽  
pp. 233-239 ◽  
Author(s):  
Neus Bellí ◽  
David Mitchell ◽  
Sonia Marín ◽  
Isabel Alegre ◽  
Antonio J. Ramos ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Meteorological Conditions ◽  
Wine Grapes
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