Search results for "toxin"
showing 10 items of 1434 documents
Occurrence of deoxynivalenol and T-2 toxin in bread and pasta commercialised in Spain
2011
Abstract Deoxynivalenol and T-2 toxin were extracted from wheat-based bread ( n = 75) and pasta ( n = 75) samples using a mixture of acetonitrile:water (86:14 v/v); for analysis, gas chromatography/mass spectrometry after derivatisation with trifluoroacetic anhydride was utilised. The recovery of deoxynivalenol and T-2 toxin from both food matrixes ranged from 90.1 to 94.0%. The occurrence of these mycotoxins in bread was 28.0% and 2.6% for deoxynivalenol and T-2 toxin, respectively, whereas in pasta, the occurrence of both mycotoxins was higher, varying from 9.3 to 62.7%. The mean content of deoxynivalenol (42.5 μg/kg) in bread was lower than the content of T-2 toxin (68.37 μg/kg), while…
Natural occurrence of emerging Fusarium mycotoxins in feed and fish from aquaculture.
2014
A new analytical method for the simultaneous determination of enniatins (ENs) and beauvericin (BEA) in fish feed and fish tissues by liquid chromatography coupled to mass spectrometry with linear ion trap (LC-MS/MS-LIT) was developed. Results showed that the developed method is precise and sensitive. The presence of emerging Fusarium mycotoxins, ENs and BEA, was determined in samples of aquaculture fish and feed for farmed fish, showing that all feed samples analyzed were contaminated with mycotoxins, with 100% coexistence. In aquacultured fish samples, the highest incidence was found in edible muscle and liver. As for the exposure assessment calculated, it was found that average consumer i…
Occurrence of fumonisins B1 and B2 in broa, typical Portuguese maize bread
2007
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides, and Fusarium proliferatum, fungi species most commonly isolated from maize. The natural occurrence of FB1 and FB2 in broa, typical Portuguese maize bread, was evaluated in 30 samples. Twenty five were found positive with levels ranging from 142 to 550 [mu]g kg- 1. The limit established by the European regulations was exceeded by 27% of the samples. The tolerable daily intake for fumonisin B1, and B2, alone or in combination, for all of the analysed samples, was lower than 2 [mu]g kg- 1 body weight per day established by the European Commission. http://www.sciencedirect.com/science/article/B…
Dietary intake of ochratoxin A from conventional and organic bread
2006
Ochratoxin A (OTA) was extracted from 100 bread samples by using accelerated solvent extraction (ASE) and analyzed with liquid chromatography coupled with fluorescence detection. The presence of OTA was confirmed by methyl-ester derivatization. Bread samples were bought from different bakeries and supermarkets, 74 of non-organic and 26 of organic bread. The incidence of OTA varied between 20.3% and 23.0% for non-organic and organic bread, respectively. The highest values were obtained with non-organic versus organic products, five samples exceeded the European maximum permitted limit of OTA (3 ng/g) for this product. Estimated daily intake of OTA in this study was 1.6 ng/kg b.w./day. This v…
Determination of Fungi and Multi-Class Mycotoxins in Camelia sinensis and Herbal Teas and Dietary Exposure Assessment
2020
In this paper, a study of fungal and multi-mycotoxin contamination in 140 Camellia sinensis and 26 herbal teas marketed in Latvia is discussed. The analysis was performed using two-dimensional liquid chromatography with time-of-flight mass spectrometry (2D-LC-TOF-MS) and MALDI-TOF-MS. In total, 87% of the tea samples tested positive for 32 fungal species belonging to 17 genera, with the total enumeration of moulds ranging between 1.00 ×
Potential of the Bacillus thuringiensis Toxin Reservoir for the Control of Lobesia botrana (Lepidoptera: Tortricidae), a Major Pest of Grape Plants▿
2006
ABSTRACT The potential of Bacillus thuringiensis Cry proteins to control the grape pest Lobesia botrana was explored by testing first-instar larvae with Cry proteins belonging to the Cry1, Cry2, and Cry9 groups selected for their documented activities against Lepidoptera. Cry9Ca, a toxin from B. thuringiensis , was the protein most toxic to L. botrana larvae, followed in decreasing order by Cry2Ab, Cry1Ab, Cry2Aa, and Cry1Ia7, with 50% lethal concentration values of 0.09, 0.1, 1.4, 3.2, and 8.5 μg/ml of diet, respectively. In contrast, Cry1Fa and Cry1JA were not active at the assayed concentration (100 μg/ml). In vitro binding and competition experiments showed that none of the toxins teste…
MARTX ofVibrio vulnificusbiotype 2 is a virulence and survival factor
2012
Vibrio vulnificus biotype 2 is a polyphyletic group whose virulence for fish relies on a plasmid. This plasmid contains an rtxA gene duplicated in the small chromosome that encodes a MARTX (Multifunctional, Autoprocessing Repeats-in-Toxin) unique within the species in domain structure (MARTX type III). To discover the role of this toxin in the fitness of this biotype in the fish-farming environment, single- and double-knockout mutants were isolated from a zoonotic strain and analysed in a series of in vivo and in vitro experiments with eel, fish cell lines and amoebae isolated from gills. Mice, murine and human cell lines were also assayed for comparative purposes. The results suggest that …
Killer toxins in new isolates of the yeasts Hanseniaspora uvarum and Pichia kluyveri
1985
From various habitats (plant material, fruits, soil), yeasts belonging to the species of Pichia kluyveri and Hanseniaspora uvarum were isolated that showed killer activity. According to the activity spectrum against other yeasts these strains belonged to 11 different groups that were distinguishable from the killer strains K1-K10. The isoelectric points of the killer proteins were in the range of pH 3.5–3.9, the activity optimum was observed at pH 4.2–4.6. Above pH 5 and above a temperature of 25–35°C the killer proteins were inactivated.
Killer toxin producing strains of the yeasts Hanseniaspora uvarum and Pichia kluyveri
1988
By heat treatment killer strains of the type K1 of Saccharomyces cerevisiae that are known to harbour dsRNA plasmids were completely cured, whereas only a small fraction of the clones of the killer type K2 had lost the dsRNA dependent killer character. The K2 killers but not the strains of killer type K1 were easily cured by cycloheximide. Killer strains of Hanseniaspora uvarum were not curable by heat treatment. Curing was successfull with cycloheximide or 5-fluorouracil. Two double-stranded RNA plasmids were detected in the killer strains of H. uvarum. The smaller dsRNA plasmid was absent in the strains that were cured of their killer character by 5-fluorouracil. The killer character of H…
Multi-mycotoxin determination in barley and derived products from Tunisia and estimation of their dietary intake.
2017
A study on raw barley and derived products (barley soup and beers) was carried out to determine the natural presence of twenty-four mycotoxins by both liquid chromatography and gas chromatography coupled to tandem mass spectrometry (MS/MS). The developed multi-mycotoxin procedure was based on both SLE and QuEChERS extraction steps. 66% of analyzed samples presented mycotoxin contamination and only one sample, which was soup of barley (6 ng/g), exceeded the maximum level (ML) established by EU for OTA (5 ng/g). Raw barley was the most contaminated matrix (62%), which concentrations ranged from 1.70 to 287.13 ng/g) and type of detected mycotoxins (DON, 15AcDON, NEO, NIV, HT2, FB1, OTA, ENA, E…