Search results for "Mycotoxins"
showing 10 items of 227 documents
Immunochemical analysis of the carbohydrate moiety of yeast killer toxin K28
1990
Killer toxin K28, a 16 kd protein secreted by the wine yeast Saccharomyces cerevisiae strain 28, was reversibly bound by a column of Concanavalin A-Sepharose, confirming its glycoprotein nature. HPLC analysis of acid hydrolyzates of K28 toxin as well as Western-blots of beta-eliminated and/or endo H-treated killer toxin preparations probed with polyclonal alpha-toxin antibodies revealed that the carbohydrate moiety of K28 consists of D-mannose only, which is O-glycosidically linked via Ser/Thr residues to the protein part. The change in gel mobility of K28 after beta-elimination was caused by a decrease in molecular mass of about 1,800, corresponding to a carbohydrate moiety of 10 mannose r…
Killer toxin of Hanseniaspora uvarum
1990
The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitiv…
Assessment of the Optimum Linker Tethering Site of Alternariol Haptens for Antibody Generation and Immunoassay Development
2021
Immunochemical methods for mycotoxin analysis require antigens with well-defined structures and antibodies with outstanding binding properties. Immunoreagents for the mycotoxins alternariol and/or alternariol monomethyl ether have typically been obtained with chemically uncharacterized haptens, and antigen conjugates have most likely been prepared with mixtures of functionalized molecules. For the first time, total synthesis was performed, in the present study, to obtain two haptens with opposite linker attachment locations. The functionalized synthetic haptens were purified and deeply characterized by different spectrometric methods, allowing the preparation of bioconjugates with unequivoc…
The Occurrence and Dietary Exposure Assessment of Mycotoxins, Biogenic Amines, and Heavy Metals in Mould-Ripened Blue Cheeses
2020
The occurrence and dietary exposure assessment of 16 mycotoxins, 6 biogenic amines (BAs), and 13 metallic elements in blue-veined cheeses (n = 46) is reported. Co-occurrence of mycophenolic acid (&le
Target Quantification and Semi-Target Screening of Undesirable Substances in Pear Juices Using Ultra-High-Performance Liquid Chromatography-Quadrupol…
2020
Fruit juices are common products in modern diets due to the supply of vegetal nutrients combined with its tastiness. Nevertheless, potential contaminants, such as mycotoxins and pesticides, can be present in commercial products due to a potential carry-over. Therefore, the aim of this study was to investigate for the first time the presence of 14 Fusarium mycotoxins using a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based extraction followed by an ultra-high-performance liquid chromatography-quadrupole Orbitrap high-resolution mass spectrometry in 21 pear juice samples from Italian markets. Up to nine different mycotoxins were detected, particularly an extensive presence of …
Study on Trichothecene and Zearalenone Presence in Romanian Wheat Relative to Weather Conditions
2019
To evaluate the influence of weather conditions on mycotoxin presence in wheat, deoxynivalenol (DON), 3-acetyldeoxynivalenol (3AcDON), 15-acetyldeoxynivalenol (15AcDON), fusarenon-X (FUS-X), nivalenol (NIV), HT-2 toxin (HT-2), T-2 toxin (T-2), diacetoxyscirpenol (DAS), neosolaniol (NEO) and zearalenone (ZEN) were evaluated in 102 Romanian wheat samples coming from five wheat growing areas during 2015. Only six mycotoxins were detected, while FUS-X, DAS, NEO and NIV were not present in the wheat samples. Mycotoxin concentrations were correlated with precipitation and temperature values during anthesis and the preharvest period. Overall, the highest frequency was registered for DON, while the…
Degradation study of enniatins by liquid chromatography–triple quadrupole linear ion trap mass spectrometry
2012
Abstract Enniatins A, A1, B and B1 (ENs) are mycotoxins produced by Fusarium spp. and are normal contaminants of cereals and derivate products. In this study, the stability of ENs was evaluated during food processing by simulation of pasta cooking. Thermal treatments at different incubation times (5, 10 and 15 min) and different pH (4, 7 and 10) were applied in an aqueous system and pasta resembling system (PRS). The concentrations of the targeted mycotoxins were determined using liquid chromatography coupled to tandem mass spectrometry. High percentages of ENs reduction (81–100%) were evidenced in the PRS after the treatments at 5, 10 and 15 min of incubation. In contrast to the PRS, an im…
Occurrence of fumonisins in organic and conventional cereal-based products commercialized in France, Germany and Spain
2013
A fast and effective method for quantitative determination of fumonisins B1 and B2 (FB1 and FB2) in different cereal-based products was developed. Fumonisins were extracted combining a solid liquid extraction (SLE) pre-treatment and immunoaffinity columns (IACs), which were applied for an effective clean-up. Consecutively, high pressure liquid chromatography (HPLC) coupled to hybrid triple quadrupole-linear ion trap mass spectrometer (QTrap®) was used for the separation, detection and quantification of targeted mycotoxins. The analytical method showed acceptable recoveries ranged from 89.7% to 99.1%, as well as a relative standard deviation (%, RSD) lower than 12%. A total of 1250 samples f…
Production of cyclopiazonic acid by molds isolated from Taleggio cheese
1999
Twenty-seven strains of Penicillium were isolated from the rind of Taleggio, a typical Italian cheese, so that we could test their capacity to produce cyclopiazonic acid (CPA); all strains produced CPA. The production was strongly influenced by the strain variety and growth conditions. Strains incubated at 25 degrees C for 7 days always produced CPA in mannitol broth, with concentrations ranging from 0.02 to 1 microg/ml, whereas only 33% of strains grown in yeast-extract broth produced CPA, with a maximum value of 0.1 microg/ml. In milk, maximum production (1.6 microg/ml) was observed after 14 days of incubation at 25 degrees C. In order to evaluate the presence of the toxin and its capacit…
Roquefortine C occurrence in blue cheese.
2001
Several strains of Penicillium are used for the production of mold-ripened cheeses, and some of them are able to produce mycotoxins. The aims of the research were the determination of roquefortine C and PR toxin in domestic and imported blue cheeses, the identification of the penicillia used as starter, and the investigation of their capacity for producing toxins in culture media. Roquefortine C was always found in the cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identification of the fungal strains present in the domestic cheeses included Penicillium glabrum, Penicillium roqueforti, and Penicillium cyclopium in the Gorgonzola "dolce" and Peni…