Species determination of pine nuts in commercial samples causing pine nut syndrome

Consumption of pine nuts from the species of Pinus armandii has been reported to cause dysgeusia, commonly known as pine mouth, or pine nut syndrome (PNS). However, the number of reports on pine nut consumptions of the different species and PNS is limited. This leaves open the possibility that other pine species than P. armandii could be involved in PNS as well. This study investigated 18 samples involved in PNS and received at the Danish Veterinary and Food Administration in 2011 through 2012. Samples were subjected to gas chromatographic analysis of fatty acids. The content of 11 individual fatty acids was used together with the diagnostic index and the sum of Δ5-fatty acids as diagnostic parameters. Diagnostic parameters from samples were then compared to reference material and literature data to determine the species. In a limited number of samples, the diagnostic parameters matched neither our reference materials nor literature data. However, the morphology, the fatty acid analysis, and externally obtained DNA sequencing data suggest a P. armandii subspecies or a variety. With these possible P. armandii subspecies, P. armandii was identified in all analyzed samples. The application of principal component analysis (PCA) to the data set showed a satisfactory separation of the majority of the 13 pine species included in the study.     

Fusarium mycotoxins in wheat samples harvested in Serbia: A preliminary survey

The objective of this study was to determine the occurrence of trichothecenes of both the A-type and B-type, masked mycotoxin derived from DON - deoxynivalenol-3-glucoside (DON-3-Glc), 3- and 15-acetyldeoxynivalenol (ADONs), fusarenon-X (FUS-X) and nivalenol (NIV)) as well as zearalenone (ZON) in winter wheat. Total of 54 samples were collected during the harvest of 2007 representing the most important Serbian wheat-growing regions. The samples were prepared by one-step simple method and analyzed by high performance liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The obtained recoveries proved that the used method could be successfully applied for multi-component analysis of Fusarium mycotoxins. DON, DON-3-Glc and HT-2 contents were detected approximately in 28%, 13% and 6% of the total number of samples, respectively. The amount of these toxins ranged from 17 μg/kg for DON-3-Glc to 309 μg/kg for DON. ADONs, FUS-X, NIV, T-2 toxin as well as ZON were below the limit of detection. Different susceptibility of wheat cultivars towards detected mycotoxins was observed. The results were compared to the EC Regulative and with available the literature data concerning the neighboring countries. This is first report on the simultaneous presence of 8 Fusarium mycotoxins in the wheat cultivated in the Balkan Countries region.     

Determination of fungal microbiota and mycotoxins in brewers grain used in dairy cattle feeding in the State of Bahia,Brazil

The aim of this study was to determine the mycoflora and evaluate the presence of aflatoxins and ochratoxins in brewers grain used to feed dairy cattle in the State of Bahia. Twenty samples of brewers grain were collected each trimester, during a whole year, in five properties located in cities of the “recôncavo baiano” (Bahia, Brazil) for a total of 80 samples. Samples were analyzed for aflatoxins and ochratoxins by fluorimetry with immunoaffinity columns. Aspergillus was the most frequently isolated genus (42.5%), followed by Penicillium, Mucor, Rhizopus and Fusarium. Mycotoxicological analyses did not show the presence of ochratoxins, but the presence of aflatoxins was observed in 33.75% (27/80) of the samples, with contamination levels between 1 and 3 μg/kg.     

Occurrence of fourteen mycotoxins in tiger-nuts

A previous developed matrix solid-phase dispersion (MSPD) extraction method was applied for the routine analysis of aflatoxins (AFs), ochratoxin A (OTA), fumonisins (FB₁ and FB₂), beauvericin (BEA), nivalenol (NIV), deoxynivalenol (DON), the toxin T-2 (T-2), toxin HT-2 (HT-2), diacetoxyscirpenol (DAS) and zearalenone (ZEN) in tiger-nuts by liquid chromatography-triple-quadrupole linear ion trap (HPLC-QTRAP^®). The extraction solid support used was C₁₈, while the elution solvent was acetonitrile/methanol (50/50, v/v) 1 mM ammonium formate. Using matrix-matched calibration, recoveries and repeatabilities were in the range 67-89% and 2-11% relative standard deviation (RSD), respectively. The method was applied to determine the occurrence of the fourteen selected mycotoxins in a total of 83 tiger-nut samples purchased from different local markets of Valencian Community (Spain) during (March-June 2010 and March-May 2011). DON, OTA, AFs and BEA were detected in 26 samples of the total number of samples.     

Occurrence of mycotoxins in fruit juices and wine

Mycotoxins are produced by secondary metabolism of various fungal species. Numerous studies were performed on the occurrence of the mycotoxins in raw commodities and foodstuffs. These studies were carried out on account of their high toxicity and the possible risk they can present for the health of the consumers. The purpose of this paper is to review the occurrence of mycotoxins in fruit juices and wine.     

Aflatoxin occurrence in nuts and commercial nutty products in Malaysia

A total of 196 nuts and their products marketed in Penang, Malaysia were assessed for aflatoxins using a monitoring scheme consisting of enzyme-linked immunosorbent assay (ELISA) for rapid screening and reversed phase high performance liquid chromatography (HPLC) for quantification and confirmation. Thirty two out of 196 samples (16.3%): six raw groundnuts shelled, two roasted groundnut in shell, three roasted groundnut shelled, one walnut, four coated nut products, two peanut cakes (gung tang), 3 pounded groundnuts, one peanut slice, seven peanut butters, one bakery product and two confectionery were contaminated with aflatoxins, ranging in levels from 16.6 μg/kg up to 711 μg/kg (mean 17.2–350 μg/kg) for total aflatoxins.     

Aflatoxin contamination in edible nuts imported in Qatar

Edible nuts imported in Qatar from June 1997 to December 1998 were anlaysed for aflatoxins. Eighty-one nut samples were analysed in the second half of 1997 and contamination was detected in 19 samples with total aflatoxin level varied from a low of about 0.53 to a high of 289 μg/kg. Aflatoxin contamination was detected in pistachios and peanuts, while other nuts such as almond, cashew nut, walnut and hazel nut were found free from aflatoxins. During 1998 testing was carried out only for pistachios and about 101 samples were analysed; contamination was detected in 48 samples with total aflatoxin level in the range of 1.2–275 μg/kg. In pistachios without shell level of contamination was very high (total aflatoxin 8.3–275 μg/kg) compared to pistachio with shell (total aflatoxin 1.2–75 μg/kg). Aflatoxin B₁ and B₂ were detected in all the contaminated samples of pistachios, whereas aflatoxin G₁ and G₂ were detected only in three samples of pistachios at the level of 0.8–1.9 μg/kg for aflatoxin G₁ and 0.4–1.3 μg/kg for aflatoxin G₂.     

Exposure assessment of mycotoxins in dairy milk

The objective of this study was to develop a quantitative Monte Carlo exposure assessment model for mycotoxins in dairy milk and to assess the potential human exposure levels. Mean concentrations of mycotoxins in milk were estimated using the simulation model (Aflatoxin M1 = 0.0161 μg/kg, Ochratoxin A = 0.0002 μg/kg, Deoxynivalenol = 1 μg/kg, Fumonisin B1 = 0.36 μg/kg, Zearalenone = 0.39 μg/kg, T-2 = 0.0722 μg/kg) while the simulated tolerable daily intakes (TDIs) from milk for males and females all fell below European Union guidelines. Aflatoxin M1 was the toxin of greatest concern as it had potential to exceed the EU limit of 0.05 μg/kg in milk. The sensitivity analysis identified the concentration of toxins in maize as the area which needs most attention in relation to crop management and agricultural practice. The sensitivity analysis assessed also identified the carry over rate as a factor closely related to risk and as a factor which required further research.     

Mycoflora and absence of aflatoxin contamination of commercialized cassava chips in Benin, West Africa

Studies conducted in Benin, in which the main staple foods are maize, cassava, groundnuts and yams, showed high levels of aflatoxin residues in blood of the exposed population. The natural contamination with fungi and aflatoxins in cassava chips sold at markets in Benin, West Africa was investigated. A total of sixty samples were sampled from open markets in 11 districts of 3 agroecological zones and analyzed for the presence of mycoflora and aflatoxin B₁, B₂, G₁ and G₂. Fourteen genera of fungi were associated with marketed dried cassava chips. Within these, twenty- two isolates were identified to species level, whereas four were identified only to genus. The dominating fungal species isolated were Rhizopus oryzae, Nigrospora oryzae, Chrysonilia sitophila, Cladosporium resinae, Cladosporium herbarum, Apergillus niger and Aspergillus flavus. Fifty-four out of sixty samples were contaminated with A. flavus. The rate of occurrence in CFU/g of A. flavus fungi was lower than for all other fungal species together. Aflatoxin was not detected in any of the samples analyzed using HPLC with post-column photochemical derivatization and fluorescence detection. The limit of detection (LOD) was 0.1 μg/kg. Results from this study suggest cassava chips are unlikely to be a source of aflatoxin in Benin, and that other staples such as maize and groundnuts are more important in aflatoxin exposure. Therefore it can be speculated that staples like maize and groundnut are more important in aflatoxin exposure.     

Occurrence and legislation of mycotoxins in food and feed from Morocco

Mycotoxins are natural food and feed contaminants, mainly produced by moulds of genera Aspergillus, Penicillium and Fusarium. The number of mycotoxins known to exert toxic effect on human and animal health is constantly increasing as well as the legislative provisions taken to control their presence in food and feed. Morocco, a North African country, surrounded by the Mediterranean Sea and Atlantic Ocean, has a climate characterized by high humidity and high temperature which favor growth of moulds. This paper gives an overview about the contamination levels and the occurrence of some mycotoxins (e.g. aflatoxins, ochratoxin A, and Fusarium toxins) in cereals, bread, milk, spices, wine, olives, poultry feeds, dried fruits and nuts; the average of contaminated samples was often above 50%. A section on mycotoxin regulations by Moroccan authorities is discussed with a comparison with international and European limits. Recent data about the contamination of foods and feed from Morocco by mycotoxins are considered in this review. Finally, the paper gives a last part with conclusions and principal prospectives and recommendations that should be undertaken by authorities and scientists during monitoring of mycotoxins in food and feed produced and/or commercialized in Morocco.     

Natural occurrence of mycotoxins in cereals and spices commercialized in Morocco

Sixty samples of cereals (20 of corn, 20 of barley, and 20 of wheat) and 55 samples of spices (14 of paprika, 12 of ginger, 14 of cumin, and 15 of pepper) purchased from popular markets of Rabat and Salé in Morocco were analyzed for mycotoxins.Cereals samples were all analyzed for ochratoxin A (OTA). The average levels of contamination were 1.08, 0.42, and 0.17 μg/kg for corn, wheat, and barley, respectively. Samples of corn were also analyzed for zearalenone (ZEA) and fumonisin B₁ (FB₁) the average contaminations were 14 and 1930 μg/kg, respectively. Co-occurrence of OTA, FB₁, and ZEA was also checked. Spices samples were analyzed only for aflatoxins (AFs) and the average contaminations found for aflatoxin B₁ (AFB₁) were 0.09, 0.63, 2.88 and 0.03 μg/kg for black pepper, ginger, red paprika and cumin, respectively. The higher level of contamination was found in red paprika (9.68 μg/kg).The present report is the first one ever drafted on the natural co-occurrence of OTA, FB₁ and ZEA in cereals and on the occurrence of AFs in spices from Morocco.     

Investigations on the occurrence of mycotoxins in beer

The occurrence of several mycotoxins, including ergot alkaloids, alternariol (AOH), deoxynivalenol (DON), and zearalenone (ZEA) in beer (n = 44) from the German market was studied by using enzyme immunoassay methods. Detection limits in beer were 2.1 μg/L (DON), 0.14 μg/L (ZEA), 0.06 μg/L (ergometrine equivalents), and 0.18 μg/L (AOH). DON was detected in 75% of the samples (2.2–20 μg/L, median 3.7 μg/L). All samples were positive for ZEA (0.35–2.0 μg/L, median 0.88 μg/L) and AOH (0.23–1.6 μg/L, median 0.45 μg/L). Most samples (93%) were positive for ergot alkaloids (0.07–0.47 μg/L, median 0.15 μg/L). Correlating toxin levels in beer with European Union tolerable daily intake (TDI) levels for DON (1 μg/kg b.w.), ZEA (0.25 μg/kg b.w.), and ergot alkaloids (0.6 μg/kg b.w.), beer does not represent a major source of intake of these toxins. No TDI data are available for AOH, but considering toxin levels in other foods, beer does not seem to be a major source of intake of this toxin either. Nevertheless, the frequency of their occurrence warrants further study of ergot alkaloids and AOH in raw materials used for beer brewing.     

Influence of gamma-radiation on mycotoxin producing moulds and mycotoxins in fruits

One hundred random fruit samples were collected and analyzed for mycotoxins and the effect of gamma-irradiation on the production of mycotoxins in fruits was studied. Analysis of fruits revealed the occurrence of penicillic acid, patulin, cyclopiazonic acid (CPA), citrinin, ochratoxin A and aflatoxin B₁. Of the 100 samples examined, 60 were positive for one or more mycotoxin. Irradiation of fruits at dose of 1.5 and 3.5 kGy decreased significantly the total fungal counts compared with unirradiated controls. After 28 days of storage at refrigeration temperature, the unirradiated fruits were contaminated with high concentrations of mycotoxins as compared with irradiated 3.5 kGy samples. Mycotoxins production in fruits decreased with increasing irradiation dose and were not detected at 5.0 kGy.     

Incidence of aflatoxins contamination in dry fruits and edible nuts collected from Pakistan

During 2012–2015, a total of 624 samples of 13 different types of dry fruits and edible nuts were collected from retail shops and local markets of Pakistan. The collected samples were then studied for the occurrence of total aflatoxins (AFs) after immunoaffinity cleanup followed by HPLC coupled with fluorescence detector and post-column derivatization unit (Kobra Cell™). The seasonal variation of AFs was studied with respect to average temperature and relative humidity in Pakistan. LOD (S/N; 3:1) and LOQ (S/N; 10:1) of the utilized method were in the range of 0.09–0.12 and 0.30–42 μg/kg, respectively. About 165 (26%) samples were found contaminated, ranging from 0.22 to 30.11 μg/kg with a mean equivalent to 0.85 ± 0.26 μg/kg. In 459 (74%) samples, the AFs contamination was found lower than detectable limit corresponding to0.12 μg/kg. In 99 (15%) samples, the contamination range of AFs was 1–4 μg/kg. However, 28 (4%) samples exceeded the maximum tolerated limit (MTL) of 4 μg/kg as imposed by EU. However, 6 (1%) samples were found beyond the MTL of20 μg/kg as regulated by USA. Highly contaminated samples were found during the months of July, August and September. Achieved data highlighted the requirement of continuous monitoring and further investigation of AFs contamination in dry fruits/edible nuts under the authority of a definite systematic surveillance program adapted as a food safety measure.     

Presence of mycotoxins in animal milk: A review

Mycotoxins can cause toxicity when ingested by humans and animals. Although the rumen is supposed to be a barrier against mycotoxins, some studies demonstrate that carry-over of mycotoxins to milk is possible. Different studies have found mycotoxin levels in animal milk, mainly related to contaminated feed for ruminants. Aflatoxin M1 is the most studied mycotoxin in milk and levels exceeding the EU maximum level for this mycotoxin in this matrix (0.050 μg/kg) have been found. Maximum levels in milk for other mycotoxins have not been established; however ochratoxin A, aflatoxins G1, G2, B1, B2 and M2, fumonisin B1, cyclopiazonic acid, zearalenone and its metabolites and deepoxy-deoxynivalenol have also been found in milk samples. Taking into account that multi-exposure to mycotoxins is the most likely scenario and co-occurrence of mycotoxins could affect their toxicological effects in humans and animals, there is a need to determine the co-occurrence of mycotoxins in milk.     

Occurrence of trichothecene mycotoxins in Brazilian corn-based food products

The trichothecenes deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), and toxins T2 (T2) and HT2 (HT2) were searched for in 78 samples of corn-based products sold in the city of Sao Paulo/Brazil. Acetonitrile:water was used for extraction and the clean-up was accomplished with Mycosep columns. Trifluoroacylation was employed before quantification and confirmation by gas chromatograph with a selective mass detector (ion trap) in electron ionization mode. The detection limits varied with the several toxin/matrix combinations and ranged from 20 to 120 ng/g. The recoveries ranged from 71 to 155%. Only two samples were found contaminated: a sample of corn grits with 555 ng/g of T2 and 767 ng/g of HT2 and a sample of corn flour that exhibited traces of DON and NIV. DAS was not detected in any sample. The results indicate a low occurrence of trichothecene mycotoxins in corn-based products commercialized in the city of Sao Paulo in spite of high levels of T2 and HT2 found in one sample and show no immediate cause of concern. Nonetheless more extensive surveys conducted for several years are advisable in order to furnish a more complete picture of the incidence of these toxins in Brazilian corn products.     

Incidence of aflatoxins in commercial nuts in the holy city of Mekkah

The incidence of aflatoxins contamination in different nuts has been studied. Two hundred and sixty four samples of nuts were collected randomly from the main outlets across seven municipalities of the holy city of Mekkah. The samples were first screened for total aflatoxins using Aflatest immunoaffinity column (IAC) technique. The IAC results showed that 70 samples (26.5%) were contaminated with AFT in levels ranged between 1.0 and 110 μg/kg. The percentages of contamination of AFT in groundnuts were (18.4%), Pistachio (34%), walnuts (50%), cashew (15%), hazelnut (43%) and almond (17%). Only 23 samples (8.7%) had levels equal or exceeded the maximum tolerable limit for AFT in EU (4 μg/kg), and only 7 samples (2.65%) had exceeded the MTL in Saudi Arabia (20 μg/kg). The samples that exceeded MTL of Saudi Arabia were five pistachio sample (110, 45, 43, 34 and 30 μg/kg) and two peanut samples (100 and 28 μg/kg). Quantitative testing of total and individual AFs was conducted in selected samples from the IAC results with contamination levels exceeded the MTL of EU (23 samples) by using HPLC and fluorescence detection. AFB1 was detected in 22 out of 23 samples with contamination level in most of the positive samples exceeded the MTL set by EU regulations (2 μg/kg). The highest levels of AFB1 were detected in two sample of pistachio (411 and 126 μg/kg) and one sample of peanut (73.9 μg/kg). Aflatoxin G2 is detected in 5 out of 23 samples, pistachio (2), walnut (2) and hazelnut (1). While, B2 and G1 were detected in 17 samples in levels ranged between ND–10.7 μg/kg and ND–12.9 μg/kg, respectively.     

Near infrared spectroscopy for determination of mycotoxins in cereals

The use of near infrared transmittance instrumentation for determination of the mycotoxin deoxynivalenol (DON) in wheat kernel samples was investigated in a Nordic pilot project. Dilution series of wheat field infected with Fusarium culmorum was used in the calibration trials. Principal component analysis and partial least square regression calculations showed that the number of factors required to predict DON was 11–13 depending on wavelength range used. The best regression model was obtained for the wavelength range 670–1100 nm with a slope of 0.949, a correlation coefficient of 0.984 and a standard error of 381 μg DON per kg. The results indicate that it may be possible in the future to develop a calibration model, which can be used to screen for DON in wheat at concentrations just above the proposed European limits for wheat flour.     

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.