A FRET-based dual-color evanescent wave optical fiber aptasensor for simultaneous fluorometric determination of aflatoxin M1 and ochratoxin A

2018 ◽  
Vol 185 (11) ◽  
Author(s):  
Dan Song ◽  
Rong Yang ◽  
Shunyan Fang ◽  
Yanping Liu ◽  
Feng Long
2009 ◽  
Vol 2 (4) ◽  
pp. 451-459 ◽  
Author(s):  
G. Bakker ◽  
E. Sizoo ◽  
A. Jekel ◽  
D.P. Pereboom-de Fauw ◽  
R. Schothorst ◽  
...  

In 2006, a duplicate diet study of children's food was carried out in the Netherlands. Parents or guardians of 123 children collected duplicates of the 24-hour diets. Levels of aflatoxin M1, aflatoxin B1, ochratoxin A, trichothecenes and fumonisins were determined. Aflatoxin M1 was detectable in 10% of the samples, with all toxin levels below the limit of quantification. Aflatoxin B1 could be detected in 80% of the samples, while in 47% of all samples aflatoxin B1 was quantifiable. Ochratoxin A could be quantified in all samples. Deoxynivalenol was quantified in almost every sample, while T-2 and HT-2 toxins could only be quantified in 3.2% and 6.4% of the samples respectively. 15-acetyldeoxynivalenol was detected in 1.6% of the samples. Fumonisin B1 was detected in 28% of the samples and fumonisin B2 in a quarter of merely those samples where fumonisin B1 was detected. In 20% of the samples fumonisin B1 could be quantified and in a quarter of those samples fumonisin B2 could be quantified too. The analytical results were used to estimate levels of daily intake. Only the mean daily intake levels for aflatoxin B1, ochratoxin A, deoxynivalenol and fumonisins B1 and B2 could reliably be estimated. The values were 0.1, 4.1, 291 and 28 ng/kg bw/day respectively, all are well below the corresponding tolerable daily intakes. For aflatoxin B1 a tolerable intake does not exist, but the intake value for this mycotoxin was very low if compared to the value that would result from the intake of food, if it was contaminated with aflatoxin B1 at the EU regulatory limit, specified for baby food. The mean daily intakes of the mycotoxins determined in children's food in the Netherlands are low and implicate that there is no health risk for children due to exposure from the studied mycotoxins.


2013 ◽  
Vol 6 (4) ◽  
pp. 355-366 ◽  
Author(s):  
M. Solfrizzo ◽  
L. Gambacorta ◽  
B. Warth ◽  
K. White ◽  
C. Srey ◽  
...  

The performances of four LC-MS/MS methodologies for determination of up to eight mycotoxin biomarkers in human urines were compared by involving three laboratories that analysed common urine samples spiked at two levels of each biomarker. Each laboratory received a calibration solution, spiked urines and the corresponding unspiked urine. The two spiking levels for each biomarker were chosen by considering the levels naturally occurring in human urines and the limits of quantification of the LC-MS/MS methodologies used by the participating laboratories. The results of each laboratory were evaluated for their z-score values. The percentage of satisfactory z-scores (| z | < 2) were: 100% for deoxynivalenol, de-epoxy deoxynivalenol, aflatoxin M1, β-zearalenol and zearalenone, 87% for α-zearalenol, 50% for ochratoxin A and 42% for fumonisin B1. Good method performances were obtained for most biomarkers at the levels tested in this study, as demonstrated by the overall percentage of satisfactory z-scores for all analytes (87%). Unsatisfactory/questionable z-scores (| z | ≯2) were obtained for fumonisin B1 (7/12 results), ochratoxin A (4/8 results) and ?-zearalenol (1/8 results). The percentage of satisfactory z-scores for fumonisin B1 and ochratoxin A increased from 42 to 83% for fumonisin B1 and from 50 to 62% for ochratoxin A when laboratories 1 and 2 used own calibrants. Factors that could explain the different results obtained for fumonisin B1 and ochratoxin A with provided and own calibration solutions could not be identified in this study and should be carefully investigated in future studies.


2014 ◽  
Vol 146 ◽  
pp. 242-249 ◽  
Author(s):  
L.C. Huang ◽  
N. Zheng ◽  
B.Q. Zheng ◽  
F. Wen ◽  
J.B. Cheng ◽  
...  

2019 ◽  
Vol 47 (1) ◽  
Author(s):  
Cagla Turkoglu ◽  
Erhan Keyvan

Background: Mycotoxins produced by yeast and fungi have toxic effects on human and animal health. Aflatoxin B1 (AFB1) is the most toxic hepatocarcinogen to mammals. Aflatoxin M1 (AFM1), which has been found in milk and dairy products, is the hydroxylated metabolite of AFB1. Aflatoxin M1 is formed by the cytochrome P450 enzyme in the liver. Ochratoxin A (OTA) is synthesized by Aspergillus and Penicillium species. Ochratoxin A is known to cause teratogenic, immunotoxic, nephrotoxic and carcinogenic effects. Due to the potential harmful effects on human and animal health, OTA has also been receiving increased attention globally; however, there is limited information on the presence of OTA in milk and dairy products. The aim of this study was to determine how mycotoxins impact the hygienic quality of raw and heat-processed milk.Materials, Methods & Results: In this study, a total of 105 milk samples were analyzed (35 raw, 35 pasteurized and 35 UHT) to identify AFM1 and OTA in raw, pasteurized and ultra-high temperature processing (UHT) milk. The levels of AFM1 were detected by using the enzyme-linked immunosorbent assay (ELISA). The milk samples were centrifugedin order to remove the fat content from the milk. After centrifugation, the upper cream layer was withdrawn with a pipette. The non-fat liquid portion was placed in wells at 100 μL for analysis. The concentration of AFM1 in the milk samples was analyzed by AFM1 test kit.The milk samples with AFM1 levels greater than 50 ng/L were confirmed by using High-Performance Liquid Chromatography (HPLC). An Ochratoxin A Serum / Milk ELISA test kit was used for the analyses of OTA. The analyses were made according to the manufacturer’s instructions, and samples were analyzed in duplicate. The absorbance value of milk samples was obtained from the ELISA plate reader at 450 nm. The mean value of AFM1 was found to be 19.54 ng/L in the milk samples. According to the European Commission (EC), the maximum limit for AFM1 in milk is 50 ng/L. In our study, eight (7.61%) of the 105 samples exceeded this limit. The mean value of OTA was found to be 119 ng/L in the milk samples. The relationship between milk type and levels of AFM1 was found to be significant at (P < 0.01). The mean value of AFM1 in pasteurized milk was found statistically significant and lower than raw milk (P < 0.05). The difference between levels of OTA and milk type was not statistically significant at (P > 0.05).Discussion: Milk is a great protein source especially for children in the age of growth.  Yeasts such as Fusarium, Aspergillus and Penicillium produce mycotoxins that cause food, feed contamination. Owing to carcinogenic, mutagenic and teratogenic effects of AFM1, presence of AFM1 in milk samples may adversely affect human health. The presence of AFM1 in different contamination levels can be observed in milk and milk products. Factors such as ration type, climate conditions, feed storage conditions, feeding regime and health status of dairy animals may be effective in the occurrence of these contamination. It is necessary to establish legal limits by conducting effective research on the existence of OTA in animal-derived products. The existence of mycotoxins in milk and dairy products can be reduced by preventing the contamination of feed materials with yeast and molds used in the feeding of dairy cows. Milk is one of the most important protein source for the human, effective hygienic controls should be applied to prevent microbiological and chemical hazards. Our data suggest that heat-treated milk may also be dangerous to human health, mycotoxins contamination should be controled with monitoring programs routinely in milk and feed materials for food safety. Determination of Aflatoxin M1 and Ochratoxin A in Raw, Pasteurized and UHT Milk in Turkey


Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
A Copra-Janicijevic ◽  
E Sofic ◽  
L Klepo ◽  
A Topcagic ◽  
I Tahirovic ◽  
...  

Author(s):  
B.A. Lapshinov ◽  
◽  
N.I. Timchenko ◽  

Spectral pyrometry was used to determine the surface temperature distribution of Si, Nb, Cu, and graphite samples when they were locally heated by continuous radiation of an Nd:YAG laser (λ = 1.064 μm). With prolonged exposure to radiation, a stationary temperature field was established in the samples. The thermal spectra were recorded with a small spectrometer in the visible range in the temperature range above 850 K. The optical fiber used to transmit the radiation spectrum to the spectrometer had an additional diaphragm with a diameter of 1 mm located at a certain distance from the fiber end, which ensured the locality of the recorded spectra. The optical fiber moved continuously along the sample, and the spectrometer recorded up to 100 spectra with a frequency of 5-10 Hz. The temperature profile of the samples was calculated based on the results of processing the spectra using the Spectral Pyrometry program.


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