Search results for "Ochratoxin A."
showing 10 items of 129 documents
Occurrence of ochratoxin A in bread consumed in Morocco
2007
Abstract One hundred samples of commercial bread purchased from January to October (2006) from retail bakeshops in five different cities (Rabat, Temara, Sale, Casablanca and Meknes) in Morocco were surveyed for the presence of ochratoxin A (OTA) using liquid chromatography coupled to fluorescence detection. The identification of OTA in positive bread samples was confirmed by methyl ester derivatization. Analytical results showed that forty eight (48%) samples were positive with OTA greater than the limit of quantification (LOQ = 0.051 ng/g). Levels of OTA in positive samples ranged between 0.14 and 149 ng/g. The average contamination of bread samples with OTA was 13 ± 1.5 ng/g. The highest …
Effect of ethanol on the ability of Oenococcus oeni to remove ochratoxin A in synthetic wine-like media
2010
The study focused on the changes in bacterial population, malolactic fermentation and ochratoxin A (OTA) levels in cultures of Oenococcus oeni performed in synthetic medium supplemented with ethanol and OTA. Growth was better in cultures containing 5% ethanol and was not observed in cultures containing 15% ethanol. The OTA removal ability of O. oeni depended on ethanol and initial OTA levels. The highest toxin removal percentage was observed in cultures containing 5% ethanol and 2 μg OTA/l. In ethanol-containing medium part of OTA was not sorbed by O. oeni and remained in the liquid medium. Thus, it cannot efficiently eliminate OTA in acidic ethanol-containing beverages, such as wine. The e…
Bee pollen, a substrate that stimulates ochratoxin A production by Aspergillus ochraceus Wilh.
2004
The capacity of bee pollen as a substrate for production of ochratoxin A (OTA) by a strain of Aspergillus ochraceus was studied. For control purposes corn, wheat and rice grains, and eleven liquid media were assayed. They were Yeast Extract Sucrose broth (YES), YES supplemented with 0.05, 0.1, 0.5, 1 and 5% bee pollen, YES supplemented with 0.5% peptone, 50% must, Wickerham medium, Aflatoxin Production medium and Coconut Broth Medium. Cultures were maintained at 28 degrees C for 4 weeks and were analyzed every seven days for OTA by liquid chromatography with fluorescence detection. OTA production in bee pollen was significantly (P < 0.01) higher than production in corn, wheat and rice grain…
Ochratoxin A in instant coffee in Italy
2012
Abstract The occurrence of ochratoxin A (OTA) in instant coffee from different brands and types was assessed. The survey covered 44 soluble coffees, 10 of which were decaffeinated, and 6 coffee products; the samples were collected in supermarkets and retail stores of Italy in 2011. The OTA was extracted, cleaned-up by immunoaffinity columns, and detected by HPLC-fluorescence detection. The detection and quantification limits were 0.05 and 0.2 μg/kg, respectively. Recovery, from samples spiked at levels of 0.5, 3.0, and 6.0 μg/kg, was 86.0 ± 7.1%, 91.0 ± 4.2%, and 91.7 ± 5.9% respectively. Forty-eight samples (96%) contained OTA at levels ranging from 0.32 to 6.40 μg/kg, always below the Eur…
Mycotoxins in herbal teas marketed in Latvia and dietary exposure assessment
2019
The occurrence of 12 mycotoxins has been analysed by liquid chromatography - time of flight mass spectrometry in the batch of 60 herbal teas purchased from drugstores in Latvia. Among the dry tea samples, 90% were positive for one to eight mycotoxins. Enniatin B and deoxynivalenol (DON) were the most frequently detected mycotoxins in 55% and 45% of the samples, respectively. DON reached the highest level, from 129 µg kg-1 in herbal blend to 5,463 µg kg-1 in wormwood tea. Ochratoxin A (OTA) and aflatoxin B1 (AFB1) were found in 10% and 20% of the samples at the concentrations ranged between 2.99-30.3 µg kg-1 and 3.40-23.7 µg kg-1. Studies of the tea infusion process indicated that 32-100% of…
A reliable screening of mycotoxins and pesticide residues in paprika using ultra-high performance liquid chromatography coupled to high resolution Or…
2016
Abstract In this study, an ultra-high performance liquid chromatography (UHPLC) coupled to a high resolution Orbitrap mass spectrometry (Orbitrap-HRMS) was demonstrated as a promising technique in high-throughput method development for the routine analysis and contamination control of mycotoxins and pesticide residues in spices. The method was applied for the analysis of fifty ground paprika samples containing blends of sweet and hot paprika harvested in Brazil and China. The efficiency and detection sensitivity of the used UHPLC-Orbitrap-HRMS technique were compared to the results obtained using a triple quadrupole tandem mass spectrometric detector (UHPLC-QqQ-MS/MS). The values of recover…
Effect of carbendazim and physicochemical factors on the growth and ochratoxin A production of Aspergillus carbonarius isolated from grapes.
2007
Carbendazim is a systemic fungicide that is commonly used on several crops (tobacco, fruit, vegetables, cereals, etc.). This fungicide is used to control fungal infections in vineyards. It is indicated against Botrytis cinerea, Uncinula necator, Plasmopara viticola and other fungi and can be used either alone or coupled with other fungicides. However, there is a lack of in-depth studies to evaluate its effectiveness against growth of Aspergillus carbonarius isolated from grapes and OTA production. A medium based on red grape juice was used in this study. Preliminary studies were performed at 0.98 a(w) and 25 degrees C using carbendazim concentrations over a wide range (1-2000 ng/ml medium) …
Multi-mycotoxin contamination of green tea infusion and dietary exposure assessment in Moroccan population
2021
Green tea infusion is one of the most widely drunk beverages worldwide due to its health benefits associated with microelements, essential oils, and polyphenols, etc. Several studies have reported that green tea is subjected to contamination by various toxigenic fungi. Thus, this work aims to investigate the co-occurrence of 15 mycotoxins [four aflatoxins (AFB1, AFB2, AFG1, AFG2), ochratoxin A (OTA), beauvericin (BEA), four enniatins (ENA, ENA1, ENB, ENB1), zearalenone (ZEN), alternariol (AOH), tentoxin (TENT), T-2 and HT-2 toxins] in green tea samples available in Morocco by liquid chromatography tandem mass spectrometry method. Analytical and consumption data were then used to assess the …
Simultaneous determination of mycotoxin in commercial coffee
2015
Abstract Mycotoxins are secondary metabolites produced by filamentous fungi that usually contaminate food products. Coffee is a natural product susceptible to mycotoxin contamination. The present study evaluates the presence of nivalenol, deoxynivalenol, T-2 and HT-2 Toxin, diacetoxyscirpenol, aflatoxin B 1 , aflatoxin B 2 , aflatoxin G 1 , aflatoxin G 2 , fumonisin B 1 , fumonisin B 2 , ochratoxin A, zearalenone, enniatin A, enniatin A 1 , enniatin B, enniatin B 1 , and beauvericin in coffee samples, using liquid chromatography tandem mass spectrometry (LC-MS/MS). The results show that zearalenone was not present in any sample. In the positive samples the contents of fumonisins ranged from…
Application of hybrid linear ion trap-high resolution mass spectrometry to the analysis of mycotoxins in beer
2011
This paper reports the application of liquid chromatography electrospray ionization ion trap-orbitrap mass spectrometry for the determination of 18 mycotoxins (aflatoxins, fumonisins, trichothecenes, ochratoxin A, sterogmatocystin, beauvaricin, zearalenone and zearalenol) in beer. The extraction procedure was carried out by solid phase extraction (SPE): SPE columns were conditioned with acetonitrile/methanol and water. Beer was loaded onto the column which was washed with water. In these conditions, the recoveries were more than 65% and the relative standard deviation (RSD) were below 18%. The lowest limits of quantification (LLOQ) ranged from 9 to 155 ng ml(-1). Matrix-matched calibration …