Search results for "OCHRATOXIN"
showing 10 items of 138 documents
Efficacy of natamycin for control of growth and ochratoxin A production by Aspergillus carbonarius strains under different environmental conditions
2007
Aims: To examine the efficacy of natamycin produced by Streptomyces natalensis against strains of Aspergillus carbonarius growth and ochratoxin A (OTA) production under different environmental factors on a grape juice-based medium. Methods and Results: Detailed studies in the range 0–20 ng ml−1 for control of growth and ochratoxin production by strains of A. carbonarius at 0·98, 0·96 and 0·94 water availabilities (aw) and 15–25°C on a fresh red grape extract medium were examined. Inhibition of growth was depending on temperature and aw level. At 15°C, 5–10 ng ml−1 natamycin was effective in reducing growth almost completely. However, at 20–25°C and all the three aw levels, growth was only…
Impact of non-selective fungicides on the growth and production of ochratoxin A byAspergillus ochraceusandA. carbonariusin barley-based medium
2010
The aim of this study was to assess the influence of the non-selective fungicides mancozeb, copper oxychloride, and sulfur on the growth and capability for producing ochratoxin A (OTA) of ochratoxigenic isolates of Aspergillus carbonarius and A. ochraceus in barley-based medium. Lag phases and growth rates were determined for each fungicide at different doses, at 15°C and 25°C and at 0.97 a(w). Mancozeb at 40 mg l(-1 )inhibited fungal growth and provided lag phases24 days at 10-20 mg l(-1) and 15°C. OTA was observed only at 25°C and doses10 mg l(-1). At 15°C, copper oxychloride proved inhibitory at 800 mg l(-1), while at 25°C growth was not delayed and only high doses decreased OTA levels. …
Accelerated solvent extraction of ochratoxin a from rice samples.
2005
In this paper, accelerated solvent extraction (ASE) for the analysis of ochratoxin A (OTA) is applied for the first time. Optimization of the method is given for the extraction of OTA from rice samples. Several parameters such as type of solvent, temperature, pressure, static time, and cell size were investigated thoroughly to find the optimal extraction conditions. The optimum ASE operating conditions were methanol as extraction solvent, 1500 psi, 40 degrees C, 5 min of static time, 50% flush volume, 60 s of purge, 1 cycle, and 11 mL cell size. The total extraction time was approximately 15 min. OTA was determined by liquid chromatography coupled with a fluorescence detector and confirmed …
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…
Porous silicon photoluminescence biosensor for rapid and sensitive detection of toxins
2017
A rapid and low cost photoluminescence (PL) immunosensor for the determination of low concentrations of Ochratoxin A(OTA) and Aflatoxine B1 (AfB1) has been developed. This biosensor was based on porous silicon (PSi) fabricated by metal-assisted chemical etching (MACE) and modified by antibodies against OTA/AfB1 (anti-OTA/anti-AfB1). Biofunctionalization method of the PSi surface by anti-OTA/ anti-AfB1 was developed. The changes of the PL intensity after interaction of the immobilized anti-OTA/anti-AfB1with OTA/AfB1 antigens were used as biosensor signal, allowing sensitive and selective detection of OTA/AfB1 antigens in BSA solution. The sensitivity of the reported optical biosensor towards…
Ochratoxin A in the morning and afternoon portions of urine from Coimbra and Valencian populations.
2008
Abstract The widespread contamination of foodstuffs and beverages by mycotoxins, such as ochratoxin A (OTA), has made the monitoring of human contamination levels essential. By using a sensitive, accurate and speedy method that combines extraction with 5% NaHCO 3 , immunoaffinity column clean-up and HPLC with fluorescence detection, the human exposure to OTA through urine analysis can be monitored. This method is less invasive than blood monitoring and has the potential to be a good marker of human exposure. The limit of quantification of the method was 0.007 ng/mL of urine, with recoveries of OTA, from urine samples spiked at levels between 0.02 and 0.1 ng/mL, higher than 91% with RSD lowe…
Blood, breast milk and urine: potential biomarkers of exposure and estimated daily intake of ochratoxin A: a review.
2015
The purposes of this review are to study potential biomarkers of exposure for ochratoxin A (OTA) in biological fluids (blood, urine and breast milk) for the period 2005-14, calculate the estimated daily intake (EDI) of OTA by using database consumption for the Spanish population, and, finally, to correlate OTA levels detected in blood and EDI values calculated from food products. The values of OTA detected in potential biomarkers of exposure for blood, breast milk and urine ranged from 0.15 to 18.0, from 0.002 to 13.1, and from 0.013 to 0.2 ng ml(-1), respectively. The calculated EDI for OTA in plasma ranged from 0.15 to 26 ng kg(-1) bw day(-1), higher than that obtained in urine (0.017-0.4…
Ochratoxin A in rice on the Moroccan retail market
2008
One hundred (100) samples of rice purchased from retail markets in five different cities (Rabat, Témara, Salé, Casablanca and Méknès) in Morocco from January to October 2006 were surveyed for the presence of ochratoxin A (OTA) using Accelerated Solvent Extraction (ASE) coupled to liquid chromatography with fluorescence detection. The identification of OTA in positive rice samples was confirmed by methyl ester derivatization. Analytical results showed a frequency of contamination of 26% of total analyzed rice samples. The percentage of contamination of samples was 24, 26.6, 16.6, 27.7 and 30% in Rabat, Témara, Méknès, Salé and Casablanca respectively. Levels of OTA in positive samples ranged…
Occurrence and daily intake of ochratoxin A of organic and non-organic rice and rice products
2005
Abstract Ochratoxin A (OTA) was extracted from 84 rice samples and rice products by using accelerated solvent extraction (ASE) and analysed with liquid chromatography coupled with fluorescence detection. Samples were collected from rice cultivars, local markets and supermarkets; 64 were of non-organic and 20 of organic production. 7.8% of non-organic samples had OTA levels from 4.3 to 27.3 μg/kg and in 30% of organic samples was detected the presence of this mycotoxin varying from 1.0 to 7.1 μg/kg. OTA presence was confirmed by methyl-ester derivatization. Rice and rice products labelled with denomination of origin (DO) were not detected OTA due to the fact that its production has implement…
Quantitative determination of ochratoxin A in vegetable foods
1982
A simple method for the quantitative determination of ochratoxin A (OA) in rice and other vegetable foods (oatmeal, coconut flakes and peas) is described. This procedure implies an acetonitrile-4% KCl -6N HCl (88+10+2) extraction of the acidic OA, subsequent twodimensional thin-layer chromatography (TLC) and detection by fluorescence after exposure to ammonia fumes (excitation at 340 nm; emission at 475 nm). The quantitative detection limit for OA in rice or coconut flakes is 2.4–4 μg/kg and the recovery is 96%. For oatmeal and peas the detection limit is only 20 μg/kg because of the interference by other metabolites.