Multiple mycotoxin co-occurrence in maize grown in three agro-ecological zones of Tanzania

In this study, the co-occurrence of multiple mycotoxins in maize kernels collected from 300 households' stores in three agro-ecological zones in Tanzania was evaluated by using ultra high performance liquid chromatography/time-of-flight mass spectrometry (TOFMS) with a QuEChERS-based procedure as sample treatment. This method was validated for the analysis of the main eleven mycotoxins of health concern that can occur in maize: aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁), aflatoxin G₂ (AFG₂), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), HT-2 toxin, T-2 toxin and zearalenone (ZEN). From each zone one major maize producing district for home consumption was chosen and 20 villages for each district were randomly selected for sampling. All mycotoxins of health concern, except for T-2 toxin, were detected in the maize samples. Particularly high levels of AFB₁ (50%; 3–1,081 μg kg⁻¹), FB₁ (73%; 16–18,184 μg kg⁻¹), FB₂ (48%; 178–38,217 μg kg⁻¹) and DON (63%; 68–2,196 μg kg⁻¹) were observed. Some samples exceeded the maximum limits set in Tanzania for aflatoxins or in European regulations for other mycotoxins in unprocessed maize. Eighty seven percent of samples were contaminated with more than one mycotoxin, with 45% of samples co-contaminated by carcinogenic mycotoxins, aflatoxins and fumonisins. Significant differences in contamination pattern were observed among the three agro-ecological zones. The high incidence and at high levels (for some) of these mycotoxins in maize may have serious implications on the health of the consumers since maize constitute the staple food of most Tanzanian population. Effective strategies targeting more than one mycotoxin are encouraged to reduce contamination of maize with mycotoxins.     

Deoxynivalenol in the wheat milling process and wheat-based products and daily intake estimates for the Southern Brazilian population

Fusarium head blight of wheat is caused by the Fusarium species that produces mycotoxins, such as deoxynivalenol (DON). The distribution of DON in wheat products can lead to high economic and health impacts. The objective of this study was to evaluate the natural distribution of DON in the wheat milling process and wheat-based products, as well as the daily intake estimates for the Southern Brazilian population. The fractions of wheat grains (milled wheat, finished flour and bran) were produced in a mill. Additionally, wheat-derived products, such as pasta, bread and crackers were analyzed. The bran fraction had the highest mean concentration of DON (2278 μg kg⁻¹), followed by milled wheat and finished flour (1895 μg kg⁻¹ and 1305 μg kg⁻¹). The distribution factor in the finished flour (69%) fraction demonstrates that DON was reduced when compared to milled wheat, by contrast of bran fraction that presents higher DON levels (120%). A percentage of 35% bran, 35% finished flour and 30% milled wheat samples would not be in compliance with future Brazilian regulations for DON levels. From the wheat-based products analyzed, 17% of whole bread and 10% of salted cracker products were contaminated with DON, with a median of 437 μg kg⁻¹ and 624 μg kg⁻¹, respectively. The finished flour was the fraction that most contributes to the daily intake of DON in Southern Brazil, representing 89.6% of the provisional maximum tolerable daily intake.     

Occurrence of four mycotoxins in cereal and oil products in Yangtze Delta region of China and their food safety risks

A total of 76 cereal and oil products collected from Yangtze Delta region of China were analyzed for occurrences of aflatoxins (AFs), aflatoxin B₁ (AFB₁), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEN). The mycotoxins were determined by the standard detection procedures using immunoaffinity column clean-up coupled with fluorometer (or HPLC-UV). ZEN was the most prevalent toxin, with the incidence of 27.6% (range = 10.0–440.0 μg kg⁻¹), and 9.2% of the evaluated samples were contaminated with a concentration higher than that of the legislation limit of China (60 μg kg⁻¹). AFs and AFB₁ were detected in 14.5% of the samples analyzed, the concentrations ranging 1.1–35.0 μg kg⁻¹ for AFs, and 1.0–32.2 μg kg⁻¹ for AFB₁; 4.0% of the samples had the concentrations of AFs and AFB₁ higher than that of the corresponding legislation limits of China (5.0, 10.0 and 20.0 μg kg⁻¹ for different products). OTA was detected in 14.5% of the cereal and oil products collected; the concentrations ranged 0.51–16.2 μg kg⁻¹. Only 2 samples showed OTA levels higher than that of the legislation limit of China (5.0 μg kg⁻¹). DON was detected in 7.9% of the samples; the concentrations ranged 100–700 μg kg⁻¹, and none of the samples showed DON concentration higher than that of the legislation limit of China (1.0 mg kg⁻¹). A total of 15.8% cereal and oil products were contaminated with at least two mycotoxins (multiple contaminations with different combinations including AFs-ZEN, AFs-OTA-ZEN, OTA-ZEN, ZEN-DON, OTA-ZEN-DON). The dietary exposure assessment results indicated that AFs (AFB₁), OTA, DON and ZEN from cereal-based products represented a series health risk to both adults and children in Yangtze Delta region of China. This is the first report of safety evaluation associated with major mycotoxins for the area.     

Occurrence and co-occurrence of Fusarium mycotoxins in wheat grains and wheat flour from Romania

In this study, the presence of fourteen Fusarium mycotoxins, legislated by the European Union – deoxynivalenol, zearalenone, HT-2 and T-2 toxins (EC/1881/2006; 2013/165/EU), or non-legislated (five trichothecens and five “emerging” mycotoxins), was evaluated in 31 whole unprocessed wheat samples and 35 white wheat flour samples from different areas of Romania. For this purpose, a validated multi-mycotoxins liquid chromatography tandem mass spectrometry method was applied. Seventy three percent of the analyzed samples contained at least one mycotoxin. The highest occurrence was for enniatin B, 71% of the analyzed samples being positive (21–407 μg kg⁻¹). Regarding the legislated mycotoxins, deoxynivalenol was detected in 14% (111–1787 μg kg⁻¹) of the samples, while zearalenone was detected in 9% (51–1135 μg kg⁻¹). Only one sample was positive for neosolaniol. Concerning the co-occurrence, 42% of the samples were contaminated with two to five mycotoxins, the most frequent being the binary or tertiary combinations of enniatins. This is the first study applied to Romanian wheat grains and flour samples using a high sensitive multi-mycotoxins method, and which included also “emerging” mycotoxins.     

In-house method validation,estimating measurement uncertainty and the occurrence of fumonisin B1 in samples of Brazilian commercial rice

Fumonisin B₁ was investigated in samples of rice intended for human consumption, including polished parboiled rice, whole grain rice and whole grain parboiled rice. Until the present, no studies on the occurrence of fumonisin B₁ have been performed on these types of rice that are commercially available in the south-eastern region of Brazil. A careful intralaboratory validation was carried out to demonstrate the fitness-of-purpose of the applied method for determining fumonisin B₁ in the three studied rice types. The performance criteria – selectivity, reliable limits of detection (50 μg kg⁻¹) and quantification (100 μg kg⁻¹), linearity (range 100–2500 μg kg⁻¹), precision (RSD values ≤ 17.0%) and recovery (71.7–112.0 %) were evaluated, and the expanded measurement uncertainty was estimated by using the data obtained from precision and recovery experiments. Matrix-matched calibration standards were employed to quantify the mycotoxin levels in the rice samples, in which the residual normality, homoscedasticity and independence were confirmed. In addition, the measurement uncertainty values are consistent with the maximum acceptable uncertainty established by European Union regulation for analytical methods for controlling mycotoxins in foodstuffs. Among the thirty-one commercial samples of rice analysed in the present study, five samples presented detectable levels of the mycotoxin, and these levels ranged from 64.8 to 163.0 μg kg⁻¹.     

Multi-class determination of pesticides and mycotoxins in isoflavones supplements obtained from soy by liquid chromatography coupled to Orbitrap high resolution mass spectrometry

A methodology has been developed to identify and quantify 257 toxic substances (including pesticides and mycotoxins) in diverse isoflavones supplements obtained from soy. Two different extraction procedures were compared, QuEChERS and “dilute and shoot”. The best results were observed when the “dilute and shoot” methodology was applied using acetonitrile acidified with formic acid (1% v/v) as extraction solvent followed by a clean-up step with Florisil cartridges. Validation of the method was carried out evaluating trueness, repeatability and intermediate precision, obtaining recoveries between 70 and 120% with relative standard deviation (RSD) values lower than 20%. Limits of detection and quantification were below 5 and 10 μg kg⁻¹ respectively. The validated methodology was applied to the analysis of real samples, finding pesticides such as flutolanil (12.2 μg kg⁻¹) and etofenprox (48.2 μg kg⁻¹). Regarding mycotoxins, aflatoxin B1 (8.2–17.1 μg kg⁻¹) and aflatoxin G2 (6.4 μg kg⁻¹) were detected.     

A survey of mycotoxins in random street-vended snacks from Lagos,Nigeria, using QuEChERS-HPLC-MS/MS

A survey in African snacks was carried out in order to evaluate the intake of 23 mycotoxins. The African snack samples were purchased from street vendors within Lagos metropolis (Nigeria) and evaluated for the presence of 23 mycotoxins using a modified QuEChERS procedure coupled with liquid chromatography-triple quadrupole linear ion trap mass spectrometer. The snacks included akara, baked coconut, coconut candy, donkwa, groundnut cake (kulikuli), lafun, milk curd (wara), fresh and dried tiger-nuts, and yam flour. Only three mycotoxins were detected in 23.8% of the studied snacks, and at concentrations ranging from 6 to 54 μg kg⁻¹. The concentrations of aflatoxin B₁ (AFB₁) and AFB₂ reached 23 μg kg⁻¹ and 3 μg kg⁻¹, respectively. Moreover a sample of baked coconut contained α-zearalenol (α-ZOL), which was up to 54 μg kg⁻¹ in coconut candy. As considers prevalence, aflatoxins and α-ZOL were not detected in lafun and groundnut-based snacks (donkwa and kulikuli), whereas each of the three mycotoxins contaminated 12.5% (1/8) of the coconut-based samples. This is the first report of α-ZOL in cassava and coconut, and their products. AFB₁ and total aflatoxins (TAFs) concentrations exceeded the maximum allowable limit recommended by National Agency for Food and Drug Administration and Control Nigeria (NAFDAC) in one sample of baked coconut (AFB₁ = 23 μg kg⁻¹ and TAFs = 26 μg kg⁻¹) and donkwa (AFB₁ = 19 μg kg⁻¹ and TAFs = 21 μg kg⁻¹).     

Multi-spectral kernel sorting to reduce aflatoxins and fumonisins in Kenyan maize

Maize, a staple food in many African countries including Kenya, is often contaminated by toxic and carcinogenic fungal secondary metabolites such as aflatoxins and fumonisins. This study evaluated the potential use of a low-cost, multi-spectral sorter in identification and removal of aflatoxin- and fumonisin-contaminated single kernels from a bulk of mature maize kernels. The machine was calibrated by building a mathematical model relating reflectance at nine distinct wavelengths (470–1550 nm) to mycotoxin levels of single kernels collected from small-scale maize traders in open-air markets and from inoculated maize field trials in Eastern Kenya. Due to the expected skewed distribution of mycotoxin contamination, visual assessment of putative risk factors such as discoloration, moldiness, breakage, and fluorescence under ultra-violet light (365 nm), was used to enrich for mycotoxin-positive kernels used for calibration. Discriminant analysis calibration using both infrared and visible spectra achieved 77% sensitivity and 83% specificity to identify kernels with aflatoxin >10 ng g⁻¹ and fumonisin >1000 ng g⁻¹, respectively (measured by ELISA or UHPLC). In subsequent sorting of 46 market maize samples previously tested for mycotoxins, 0–25% of sample mass was rejected from samples that previously tested toxin-positive and 0–1% was rejected for previously toxin-negative samples. In most cases where mycotoxins were detected in sorted maize streams, accepted maize had lower mycotoxin levels than the rejected maize (21/25 accepted maize streams had lower aflatoxin than rejected streams, 25/27 accepted maize streams had lower fumonisin than rejected streams). Reduction was statistically significant (p < 0.001), achieving an 83% mean reduction in each toxin. With further development, this technology could be used to sort maize at local hammer mills to reduce human mycotoxin exposure in Kenya, and elsewhere in the world, while at once reducing food loss, and improving food safety and nutritional status.     

A reliable screening of mycotoxins and pesticide residues in paprika using ultra-high performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry

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 recovery (75–120%) and repeatability (8–15%) for both methods, calculated as the average (n = 5) from the results of spiked (10–500 μg kg⁻¹), paprika samples, were in good conformity to the relevant EU guidelines. The high resolution of the used Orbitrap-HRMS technique provided a better sensitivity for quantitative determination of several pesticide contaminants in paprika, compared to the results obtained by the QqQ-MS/MS method and were comparable in case of mycotoxins. The results of analysis demonstrated the ubiquitous presence of three mycotoxins (fumonisin B₁, ochratoxin A, and sterigmatocystin) and twelve pesticide residues in paprika. The concentrations of determined contaminants were below the MRLs set by the Regulations of the European Union with exception of iprovalicarb, which violated the EU MRL in two samples of hot paprika. In addition, a notable difference in the concentration of fumonisin B₁ was determined depending on the harvest period (2009–2013), reaching the maximum concentrations of 33 μg kg⁻¹ in sweet paprika and 140 μg kg⁻¹ in hot paprika. There was no significant correlation found between the determined mycotoxin contamination levels and the pesticide residues, with the sole exception of decreased fumonisin B₁ content in samples with an elevated concentration of metalaxyl fungicide.     

Co-occurrence and evaluation of mycotoxins in organic and conventional rye grain and products

A study on the co-occurrence of Fusarium toxins in conventional and organic grain and derived products was carried out. A total of 117 samples were collected during the period 2009–2012. Eight mycotoxins were determined using the LC-MS/MS method. Among the investigated mycotoxins, four were of major importance: DON, ZEN, T-2 and HT-2. DON was present at the highest concentration in both the agricultural systems, with its maximum level of 254 ± 23 μg kg⁻¹ being present in conventional rye grain. The co-occurrence of two or more mycotoxins was observed in more than 50% of samples, with the most frequent combination being DON + ZEN. The correlation between the concentrations of T-2 and HT-2, DON and ZEN, as well as T-2 and ZEN was confirmed statistically. The concentration of DON, HT-2 and T-2 was significantly higher in conventional products. Also the higher level of ZEN in organic grain in comparison to derived products was significant. None of the samples contained DAS, while NlV, MAS and 3ADON concentrations were close to the detection limits.     

Gold nanoparticles-based lateral flow immunoassay with silver staining for simultaneous detection of fumonisin B1 and deoxynivalenol

A lateral flow immunoassay with silver staining for the simultaneous detection of fumonisin B₁ (FB₁) and deoxynivalenol (DON) in maize samples was reported. The assay was based on the competition between target mycotoxins and corresponding coating antigens immobilized on test lines for binding to limited gold nanoparticles (AuNPs)-labeled antibodies. The detection signal was further amplified by employment of silver staining on AuNPs. In the process, silver ions were catalyzed by AuNPs into metal silver that deposited on the surface of AuNPs, allowing not only the enlargement of particle dimensions of AuNPs but also a more distinguishable black coloration on the test zone. Under optimized conditions, the cut-off values of silver staining lateral flow immunoassay were 2.0 ng mL⁻¹ for FB₁ and 40 ng mL⁻¹ for DON in buffer, which was improved at least 2 times in comparison to those of AuNPs-based method. The assay was further applied to detect FB₁ and DON in naturally contaminated maize samples and a good agreement was found with the data obtained from HPLC-MS/MS.     

A survey of seasonal variations of aflatoxin M1 in raw milk in Tangshan region of China during 2012–2014

Total 530 samples of raw milk were collected from the dairy farms in the Tangshan region of north China during four seasons each year from 2012 to 2014, and aflatoxin M1 (AFM1) contents were measured using HPLC-MS/MS. The results showed that AFM1 was detected in 280 samples (52.8%) at the range of 10–200 ng L⁻¹, and the mean level of AFM1 was 73.0 ng L⁻¹, which was below the China and US legal limit of 500 ng L⁻¹. The incidences of AFM1 contamination were 27.5% in spring, 39.0% in summer, 71.7% in autumn and 78.9% in winter, respectively. It indicated that seasonal variations should be considered for the AFM1 control particularly during winter season. In comparison with the data from different years, the incidences of AFM1 contamination in raw milk samples were 87.8% with a range of 10.0–160 ng L⁻¹ in 2012, 29.9% with 10.0–190.0 ng L⁻¹ in 2013 and 36.7% with 12.0–111.0 ng L⁻¹ in 2014. Hence, present study exhibits a significant decrease in the incidence of AFM1 contamination in Tangshan region after 2012.     

Development,optimization and validation of QuEChERS based liquid chromatography tandem mass spectrometry method for determination of multimycotoxin in vegetable oil

In recent years, vegetable oils have been reported to be contaminated by mycotoxins. A new method was developed, optimized and validated for the simultaneous determination of aflatoxins (AFs), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEA) in vegetable oil by a modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) technique. A quick procedure of mycotoxins extraction and clean-up was achieved in two steps. Firstly, target analytes were extracted into the optimized solvent acetonitrile and followed by dispersive solid phase extraction (d-SPE) sorbent clean up with the optimized sorbents to remove the co-extracts. Three types of d-SPE sorbents; C18; Primary Secondary Amine (PSA); Graphitized Carbon Black (GCB) and four combination ratios of two selected d-SPE sorbent were evaluated to achieve an optimum and acceptable result. The maximum co-extracts were removed when C18 and GCB were used at ratio 3:1 with MgSO₄ anhydrous followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The validation study showed all analytes could be detected between 0.01 and 650.17 ng g⁻¹ concentration ranges with correlation coefficient >0.98. The limit of quantitation ranges from 0.04 to 2000 ng g⁻¹. The recoveries were in a range of 87.9–106.6%. The repeatability and reproducibility of the analysis were between the ranges of 0.5–1.3, within the acceptable level for precision. Significant matrix effect was compensated using the matrix matched calibration curves. The method was successfully applied to 25 vegetable oil samples including corn oil, palm oil and sunflower oil. ZEA, AFG₂, AFG₁ and AFB₁ were among the detected analytes.     

Estimated daily intake of organochlorine pesticides from dairy products in Brazil

The estimated daily intake (EDI) of organochlorine (OC) pesticides (HCB, α-HCH, lindane, aldrin, p,p′-DDE, p,p′-DDD, and o,p′-DDT) through consumption of dairy products from Rio Grande do Sul State (Brazil) was investigated. Fluid milk and cheese had similar ΣOC levels (26.04 and 26.14 ng g⁻¹ fat, respectively), whereas milk powder had lower levels (2.23 ng g⁻¹ fat). OC levels in UHT milk exhibited a declining trend over time (ΣOC = 27.70 ng g⁻¹ fat in 2000 vs. 1.50 ng g⁻¹ fat in 2009/2010). The EDI of OC pesticides was remarkably higher for children (8.266 ng kg⁻¹ day⁻¹) than for adolescents, adults, and the elderly (ranging from 0.393 ng kg⁻¹ day⁻¹ to 0.614 ng kg⁻¹ day⁻¹). The average EDIs for OC pesticides were below the acceptable daily intakes (ADI), with the exception of aldrin, which greatly exceeded the ADI for children. In addition, some samples (8.8%) exceeded the maximum residue limit for the compounds evaluated.     

Co-occurrence of aflatoxins and ochratoxin A in spices commercialized in Italy

A total of 130 spice samples coming from India, China, South America, USA, Northern Africa, Europe and Sub-Saharan Africa were collected in different stores of Northern Italy. They were analysed for aflatoxins (AFs: AFB₁, AFB₂, AFG₁, AFG₂) and ochratoxin A (OTA) content by liquid chromatography with mass spectroscopy and positive electrospray ionization (LC/ESI-MS/MS), and HPLC with fluorescence detector (FLD), respectively. The analysis showed that 20 (15.4%) and 31 (23.8%) out of 130 samples were contaminated with AFs and OTA, respectively. A low level of total AFs contamination was found in the positive samples, the average concentration was 0.64 ng g⁻¹, far below the maximum threshold admitted by the European legislation (5 ng g⁻¹ for AFB₁, and 10 ng g⁻¹ for total aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂). A higher incidence of OTA was found in chili (60.0%) more than in pepper (13.3%), ranging from 2.16 to 16.35 ng g⁻¹, and from 1.61 to 15.85 ng g⁻¹, respectively. Moreover, three spice samples (2.3%) contaminated by OTA trespassed the threshold admitted by the European Regulation (EC, 2010). The co-occurrence of OTA and AFs in spices was detected in 6 out of 130 samples (4.6%), ranging from 1.61 to 15.85 ng g⁻¹ and from 0.57 to 3.19 ng g⁻¹, respectively.     

Mycotoxins in food from Jordan: Preliminary survey

This study was undertaken to determine the presence of mycotoxins in foods from Jordan. For this purpose, a total of 108 samples of different groups of foods widely consumed by the Jordanian population were collected during 2008–2009 years. Samples were analyzed for contamination with aflatoxins, ochratoxin A, deoxynivalenol, fumonisins, zearalenone and T-2 toxin by direct competitive enzyme-linked immunosorbent assay (ELISA). The predominant mycotoxin was ochratoxin A with a mean level of 4.17 μg kg⁻¹ in 25% of analyzed samples. Furthermore, aflatoxins, deoxynivalenol and fumonisins were detected with a contamination frequency of 3%, 4% and 2%, respectively. The present report is the first one ever carried out on the occurrence of mycotoxins in food consumed by the Jordanian population.     

Statistical comparison of Fusarium mycotoxins content in oat grain and related products from two agricultural systems

A total of 98 samples of oat grain and products from two farming systems were collected during the period of 2009–2011 and analyzed for the presence of trichothecenes (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, T-2 toxin, HT-2 toxin, monoacetoxyscirpenol, diacetoxyscirpenol) and zearalenone using liquid chromatography–tandem mass spectrometry method. All mycotoxins were found at different frequency and levels in the tested oat samples; however, a higher intensity of distribution of DON, T-2 and HT-2 toxins was found in the conventional system of farming than in organic. The highest concentration in both systems (up to 655 μg kg⁻¹) was that of the mycotoxin NIV.     

Evaluation of dispersive liquid–liquid microextraction for the determination of patulin in apple juices using micellar electrokinetic capillary chromatography

Patulin (PAT) is a mycotoxin naturally found in fruits, including apples. Its occurrence as a natural contaminant of fruit juices is indicative of fruit quality in production. The European Union has set the maximum content of patulin in 50 μg kg⁻¹ for fruit juices and 10 μg kg⁻¹ for infant fruit juices. In this paper, dispersive liquid–liquid microextraction (DLLME) has been proposed for the extraction and preconcentration of PAT in apple juice, followed by its determination by micellar electrokinetic chromatography (MEKC) with diode-array detection. PAT has been analyzed in the presence of 5-hydroxymethylfurfural (HMF), which is the main interference in this kind of matrix. Variables affecting DLLME efficiency were optimized and the calibration curve was established for PAT in analyte standard solutions, applying the DLLME–MEKC procedure. The limit of detection was 0.6 μg L⁻¹ and recoveries obtained for spiked freshly-made apple juice samples at four different concentration levels (5, 20, 50 and 75 μg L⁻¹), were above 75% with RSD lower than 9%. This method can be classified as a green alternative, being successfully applied to the measurement of 19 apple juice samples obtained from different suppliers and supermarkets. The optimized DLLME–MEKC method is free from matrix effects and avoids the tedious matrix-matched or standard addition calibration method. Almost fifty percent of the samples were contaminated with a PAT content greater than the maximum content established by the European regulation.     

Occurrence of volatile and non-volatile N-nitrosamines in processed meat products and the role of heat treatment

Most of the available data on the occurrence of N-nitrosamines (NA) in processed meat products have been generated in the 1980s and 1990s and especially data on the occurrence of non-volatile NA (NVNA) are scarce. Therefore we have studied the levels of volatile nitrosamines (VNA) and NVNA in processed meat products on the Danish market (N = 70) and for comparison also products on the Belgian market (N = 20). The effect of heat treatment on the NA levels, in selected samples, was also studied, in order to enable an evaluation of how preparation before consumption affects the levels of NA. For the Danish products the mean levels of the VNA were generally low (≤0.8  μg kg⁻¹), whereas the mean levels of the NVNA were considerably higher (≤118 μg kg⁻¹). Slightly higher mean levels were indicated for the Belgian products (i.e. VNA ≤1.5  μg kg⁻¹ and NVNA ≤270 μg kg⁻¹). The sums of VNA were higher than 10 μg kg⁻¹ for one Danish sample and two Belgian samples. Levels of up to 2000 and 4000 μg kg⁻¹ of N-nitroso-thiazolidine-4-carboxylic acid (NTCA) an NVNA occurred in the Danish and the Belgian samples, respectively. The majority of the Danish processed meat products contain NVNA but also VNA occur. The levels of NA are comparable with those reported in previous and recent studies; however the frequency in which they are found may be lower and thereby also the mean contents. The levels of N-nitrosopiperidine (NPIP) increased by frying and baking, whereas varying impacts were observed for N-nitrosoproline (NPRO), N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodiethylamine (NDEA) and N-nitrosomethylaniline (NMA) depending on the type of product and/or the heat treatment. The levels of the NVNA, NTCA and N-nitroso-2-methyl-thiazolidine 4-carboxylic acid (NMTCA) decreased after frying and baking.     

A survey on the occurrence of aflatoxin M1 in raw milk produced in Adana province of Turkey

During 2012, a total of 176 samples of raw milk obtained from dairy plants of Adana province of Turkey were analysed for the presence of aflatoxin M₁ (AFM₁). Aflatoxin M₁ analysis was carried out by centrifugation, liquid–liquid extraction, immunoaffinity column clean-up and high performance liquid chromatography with fluorescence detection (HPLC-FD). The limits of detection (LOD) and quantification (LOQ) of the analytical method were 0.021 μg kg⁻¹ and 0.025 μg kg⁻¹. Accuracy of the method obtained from bias ranged from 2.94 to 8.70. Aflatoxin M₁ was detected in 53 out of 176 samples analysed (30.1%). The ranges for positive samples were 0.042–0.552, 0.033–1.01, 0.047–0.150 and 0.025–0.102 μg kg⁻¹ in autumn, winter, spring and summer seasons, respectively. Thirty samples of raw milk (17%) were above the legal limits of Turkey and EU regulations.