Aflatoxin M1 in milk and distribution and stability of aflatoxin M1 during production and storage of yoghurt and cheese

AbstractThe objective of this study was to investigate the incidence and occurrence of aflatoxin M1 (AFM1) in Brazilian milk and infant formula. The distribution and stability of AFM1 in cheese and yoghurt were also determined. Milk samples and infant formula samples were purchased in Ribeirão Preto-SP, Brazil and were analyzed for AFM1 using immunoaffinity column purification, liquid chromatography separation and fluorescence detection. AFM1 was detected in 83% of the milk samples (>3 ng/kg) with levels ranging from 8 to 437 ng/kg for fluid milk, and 20–760 ng/kg for powdered milk. No AFM1 was found in infant formula. Processing and storage was shown to have little effect on AFM1 content in milk and milk products. Total AFM1 mass in milk was reduced by 3.2% in cheese and by 6% in yoghurt (pH 4.4). The mean concentration of AFM1 in curds was 1.9-fold higher and whey was 0.6-fold lower than in unprocessed milk

Aflatoxin M1 and ochratoxin A in human milk in Ribeirão Preto-SP, Brazil

The objective of this study was to determine the extent of aflatoxin M1 (AFM1) and ochratoxin A (OTA) contamination in human breast milk in the city of Ribeirão Preto, São Paulo State, Brazil. During 2012, 100 samples of human milk were collected at the local Human Milk Bank. The method comprised, immunoaffinity column purification and isolation, liquid chromatography separation and fluorescence detection. The average percentage recoveries of AFM1 and OTA spiked at 20 and 50 ng/L in control human milk were 78.1 ± 11.7% and 73.7 ± 9.6%, respectively. The average relative standard deviations of AFM1 and OTA spiked at the same levels were 11.7 and 9.6% respectively. The limits of detection was 0.3 ng/L for AFM1 and OTA. The limit of determination was 0.8 ng/L for both mycotoxins. This method was used to analyze 100 human milk samples, of which, two samples were found to contain AFM1 at level greater than 0.3 ng/L. OTA was detected in 66 samples (66%), wherein 32 were above the limit of detection and 34 were in the range of from 0.8 to 21 ng/L. Results of our study indicate that breast-fed Brazilian infants had only an insignificant exposure to AFM1 and OTA

Dopant-Assisted Atmospheric Pressure Photoionization of Patulin in Apple Juice and Apple-Based Food with Liquid Chromatography–Tandem Mass Spectrometry

A dopant-assisted atmospheric pressure photoionization (APPI) with liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to determine patulin in apple juice and apple-based food. Different dopants, dopant flow rates, and LC separation conditions were evaluated. Using toluene as the dopant, the LC-APPI-MS/MS method achieved a linear calibration from 12.5 to 2000 μg/L (<i>r</i>² > 0.99). Matrix-dependent limits of quantitation (LOQs) were from 8 μg/L (solvent) to 12 μg/L (apple juice). [¹³C]-Patulin-fortified apple juice samples were directly analyzed by the LC-APPI-MS/MS method. Other apple-based food was fortified with [¹³C]-patulin, diluted using water (1% formic acid), centrifuged, and filtered, followed by LC-APPI-MS/MS analysis. In clear apple juice, unfiltered apple cider, applesauce, and apple-based baby food, average recoveries were 101 ± 6% (50 μg/kg), 103 ± 5% (250 μg/kg), and 102 ± 5% (1000 μg/kg) (av ± SD, <i>n</i> = 16). Using the suggested method, patulin was detected in 3 of 30 collected market samples with concentrations ranging from 13C]-patulin allowed quantitation using solvent calibration standards with satisfactory precision and accuracy

Multi-mycotoxin Analysis of Finished Grain and Nut Products Using High-Performance Liquid Chromatography–Triple-Quadrupole Mass Spectrometry

Mycotoxins in foods have long been recognized as potential health hazards due to their toxic and carcinogenic properties. A simple and rapid method was developed to detect 26 mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, and ergot alkaloids) in corn, rice, wheat, almond, peanut, and pistachio products using high-performance liquid chromatography–triple-quadrupole mass spectrometry. Test portions of homogenized grain or nut products were extracted with acetonitrile/water (85:15, v/v), followed by high-speed centrifugation and dilution with water. Mean recoveries (± standard deviations) were 84 ± 6, 89 ± 6, 97 ± 9, 87 ± 12, 104 ± 16, and 92 ± 18% from corn, rice, wheat, almond, peanut, and pistachio products, respectively, and the matrix-dependent instrument quantitation limits ranged from 0.2 to 12.8 μg/kg, depending on the mycotoxin. Matrix effects, as measured by the slope ratios of matrix-matched and solvent-only calibration curves, revealed primarily suppression and were more pronounced in nuts than in grains. The measured mycotoxin concentrations in 11 corn and wheat reference materials were not different from the certified concentrations. Nineteen mycotoxins were identified and measured in 35 of 70 commercial grain and nut products, ranging from 0.3 ± 0.1 μg/kg (aflatoxin B₁ in peanuts) to 1143 ± 87 μg/kg (fumonisin B₁ in corn flour). This rapid and efficient method was shown to be rugged and effective for the multiresidue analysis of mycotoxins in finished grain and nut products

Multi-mycotoxin Analysis of Finished Grain and Nut Products Using Ultrahigh-Performance Liquid Chromatography and Positive Electrospray Ionization–Quadrupole Orbital Ion Trap High-Resolution Mass Spectrometry

Ultrahigh-performance liquid chromatography using positive electrospray ionization and quadrupole orbital ion trap high-resolution mass spectrometry was evaluated for analyzing mycotoxins in finished cereal and nut products. Optimizing the orbital ion trap mass analyzer in full-scan mode using mycotoxin-fortified matrix extracts gave mass accuracies, δ_M, of <±2.0 ppm at 70 000 full width at half maximum (FWHM) mass resolution (<i>R</i>_FWHM). The limits of quantitation were matrix- and mycotoxin-dependent, ranging from 0.02 to 11.6 μg/kg. Mean recoveries and standard deviations for mycotoxins from acetonitrile/water extraction at their relevant fortification levels were 91 ± 10, 94 ± 10, 98 ± 12, 91 ± 13, 99 ± 15, and 93 ± 17% for corn, rice, wheat, almond, peanut, and pistachio, respectively. Nineteen mycotoxins with concentrations ranging from 0.3 (aflatoxin B₁ in peanut and almond) to 1175 μg/kg (fumonisin B₁ in corn flour) were found in 35 of the 70 commercial grain and nut samples surveyed. Mycotoxins could be identified at δ_M < ±5 ppm by identifying the precursor and product ions in full-scan MS and data-dependent MS/MS modes. This method demonstrates a new analytical approach for monitoring mycotoxins in finished grain and nut products