Studies into the occurrence of some trichothecene mycotoxins in UK home-grown wheat and in imported wheat

A total of 199 UK home-grown wheat samples collected over three harvests (1980–82 inclusive) and 33 imported wheat samples were analysed for the presence of seven trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, neosolaniol, diacetoxyscirpenol, HT-2 toxin and T-2 toxin). Analysis was performed by a gas–liquid chromatographic method and positive results greater than 0.1 mg kg^?1 were confirmed by mass spectrometry. The only mycotoxin detected in any of the samples was deoxynivalenol (vomitoxin) which occurred in 32 out of 199 UK home-grown wheats at levels ranging from 0.02 to 0.40 mg kg^?1 and 23 out of 33 imported wheats at levels ranging from 0.02 to 1.32 mg kg^?1. Microbiological evidence suggests that the lower incidence and levels of deoxynivalenol in UK, other EEC and Western Canadian wheat compared with Eastern Canadian and Midwest US wheat may be caused by a geographical variation in the distribution of Fusarium species.     

Natural occurrence of zearalenone and trichothecene toxins in maize-based animal feeds in zambia

A year-long collection of maize-based animal feed samples from the National Milling Company and mouldy maize collected from farmers fields near Lusaka were analysed for Fusarium mycotoxins. In the survey, 148 samples were tested for zearalenone, deoxynivalenol and nivalenol, and 60 samples for T-2 toxin and diacetoxyscirpenol. Zearalenone was present up to 0.6 mg kg^?1 in 17% of the feed samples, and deoxynivalenol was found at I-0 mg kg^?1 in 1.4 % of these samples. This is the first report of these toxins in animal feeds in Zambia. Zearalenone was also found in 57.6 % of the 33 mouldy maize samples collected at levels ranging from 0.08 to 6.0 mg kg^?1 (mean concentration 1.11 mg kg^?1), and 49.5% of these samples contained deoxynivalenol at levels ranging from 0.5 to 16.0 mg kg^?1 (mean concentration 5.56 mg kg ^?1). T-2 toxin and diacetoxyscirpenol were not detected.     

Natural occurrence of Fusarium toxins in peanut,sorghum and maize from Mysore (India)

Peanut, sorghum and maize samples were collected from the wholesale market in Mysore, India, over a period of one year (October 1984 to September 1985). The samples were analysed for the natural occurrence of T-2 toxin (T-2), diacetoxyscirpenol (DAS) and zearalenone by thin-layer chromatography, dermal toxicity test and gas chromatography. Of the total number of peanut samples analysed, 6.9% were positive for the toxic trichothecene(s) (T-2, up to 38.89 mg kg^?1; DAS, up to 2.03 mg kg^?1); 4.8% of total sorghum samples analysed contained T-2 up to 15 mg kg^?1. Zearalenone was not found in any of the samples tested, and no toxins were detected in any of the maize samples. Samples marketed during winter and summer periods were contaminated with the toxins. All the toxin-positive samples except one peanut sample were found in produce stored for more than a week.     

Survey of pesticide residues in maize,cowpea and millet from northern Cameroon: part I

In northern Cameroon, the misuse of pesticides for pest control is common among small-scale farmers. Therefore, monitoring of pesticide residues was carried out on stored maize, cowpea and millet from eight localities. The determination of residues of organochlorines (lindane, α-endosulfan and β-endosulfan), organophosphorus compounds (malathion and pirimiphos-methyl), synthetic pyrethroids (permethrin) and carbamates (carbufuran) was performed using GC–ECD/NPD and GC–MS for confirmation. Organochlorine pesticides were detected more frequently and in higher concentrations, ranging from 0.02 ± 0.01 mg kg^?1 for β-endosulfan in millet to 9.53 ± 4.00 mg kg^?1 lindane in maize, than organophosphorus compounds, with concentrations varying from 0.04 ± 0.03 mg kg^?1 for pirimiphos methyl to 0.23 ± 0.38 mg kg^?1 for malathion in maize. Permethrin was found only in maize at 0.39 ± 0.23 mg kg^?1. No carbofuran was found. More than 75% of samples contained pesticide residues above the maximum residue limit (MRL); showing a potential human dietary risk related to consumption of these grains.     

Quantitative analysis of styrene monomer in foods. A limited East Australian Survey

The levels of styrene monomer in foods packaged in polystyrene containers were determined by a headspace gas chromatography (g.c.) method and two reversed phase high-performance liquid chromatography (h.p.l.c.) methods. A total of 146 samples were analysed from Victoria and New South Wales which included yoghurt, cream, cheese, dessert, ice cream, egg white, onion dip and margarine. The highest level of styrene found was 0.1 mg kg^?1 in yoghurt. About 85% of all yoghurt samples were found to have values less than 0.05 mg kg^?1. The lowest values of styrene obtained were for margarine samples, of which more than 90% contained less than 0.010 mg kg^?1. The estimated limits of detection of the h.p.l.c. methods for all products except margarine were 0.005 mg kg^?1. The h.p.l.c. detection limit for margarine and the g.c. method for yoghurt were estimated to be 0.01 mg kg^?1.     

Occurrence of the C-series fumonisins in maize from the former Transkei region of South Africa

Fumonisins are a group of structurally related mycotoxins produced mainly in maize by Fusarium verticillioides and F. proliferatum. The most abundant naturally occurring analogue is fumonisin B₁ (FB₁), with lesser amounts of fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃) occurring. The C-series fumonisins (FCs) are structurally analogous to the B-series but lack the C-1 methyl group. Good and mouldy subsistence-grown maize samples were collected from the Centane and Bizana districts in the former Transkei region of South Africa. After extraction with methanol/water and clean-up on strong anion exchange solid phase extraction cartridges, FB₁, FB₂, FB₃, FC₁, FC₃ and FC₄ were determined by reversed-phase LC–MS/MS using positive ion electrospray ionisation. FB₁ levels in both good and mouldy maize from Centane (means (±SD) 2.75?±?2.24 and 23.4?±?12.5?mg?kg^?1, respectively) were higher than the corresponding levels in maize samples from Bizana (means 0.056?±?0.157 and 3.71?±?5.01?mg?kg^?1, respectively). Similarly, FC₁ levels in both good and mouldy maize from Centane (means 0.107?±?0.099 and 0.814?±?0.391?mg?kg^?1, respectively) were higher than in Bizana, where FC₁ was detected in only one (0.018?mg?kg^?1) of 19 good maize samples and occurred in mouldy maize with a mean of 0.102?±?0.135?mg?kg^?1. A significant correlation (r?=?0.982, p?<?0.01) was observed between FB₁ and FC₁ levels in all samples, with FC₁ levels at 3.3% of the corresponding FB₁ levels. FC₄ levels were similar to FC₁, whereas only low amounts of FC₃ were detected.     

Occurrence of Fusarium mycotoxins in maize imported into the UK, 2004–2007

This study examined a total of 82 consignments of French and Argentinean raw maize as received at maize mills in the UK between 2004 and 2007. Samples were analysed for deoxynivalenol (DON), nivalenol (NIV), other trichothecenes, zearalenone (ZON), and fumonisins B₁, B₂, and B₃ (FB₁, FB₂, and FB₃) using fully validated analytical methods with limits of quantification of 10 µg kg^?1 for DON, NIV, and each fumonisin mycotoxin and 3 µg kg^?1 for ZON. All samples except two containing fumonisins met the European Commission statutory maximum permissible levels for DON, ZON, and FB₁ + FB₂ as operating in 2007. The maximum concentrations found for DON, NIV, ZON, and FB₁ + FB₂ were 444, 496, 165 and 5002 µg kg^?1, respectively. Fumonisins were detected in almost every sample with 65% of Argentinean maize containing more than 1000 µg kg^?1 of FB₁ + FB₂. In contrast, ZON was not detectable in almost 50% of consignments. During this period there was a distinct difference in mycotoxin concentrations between harvests and geographic origin. Flint maize from Argentina usually contained lower concentrations of DON and related trichothecenes and higher levels of fumonisins than maize from France, although concentrations of fumonisins up to 2000 µg kg^?1 or greater occurred in samples from both regions. The incidence and concentrations of fumonisins were similar to those in a similar previous survey, while zearalenone concentrations were lower. The distribution of mycotoxins in multi-hold ships was also investigated showing that fumonisins were much more evenly distributed than DON, thus indicating their general level in the ship as a whole. The effect of cleaning regimes was found to be very variable, especially for DON, ranging from no removal of mycotoxins to greater than 50% in some instances, but was not related to concentration. Evidence here suggests that while cleaning is essential for removing foreign bodies before milling, it cannot be used as a reliable tool for reducing mycotoxins.     

Mycotoxin contamination of home-grown maize in rural northern South Africa (Limpopo and Mpumalanga Provinces)

The aim of this study was to assess mycotoxin contamination of crops grown by rural subsistence farmers over two seasons (2011 and 2012) in two districts, Vhembe District Municipality (VDM, Limpopo Province) and Gert Sibande District Municiality (GSDM, Mpumalanga Province), in northern South Africa and to evaluate its impact on farmers’ productivity and human and animal health. A total of 114 maize samples were collected from 39 households over the two seasons and were analysed using a validated liquid chromatography-tandem mass spectrometry mycotoxins method. Aflatoxin B₁ (AFB₁) occurrence ranged from 1 to 133 µg kg^?1 in VDM while AFB₁ levels in GSDM were less than 1.0 µg kg^?1 in all maize samples. Fumonisin B₁ levels ranged from 12 to 8514 µg kg^?1 (VDM) and 11–18924 µg kg^?1 (GSDM) in 92% and 47% positive samples, respectively, over both seasons. Natural occurrence and contamination with both fumonisins and aflatoxins in stored home-grown maize from VDM was significantly (p < 0.0001) higher than from GSDM over both seasons.     

A survey of styrene monomer levels in foods and plastic packaging by coupled mass spectrometry—automatic headspace gas chromatography

An extensive UK survey of styrene monomer levels in styrene based plastic packaging materials and their contained foods (133 samples) has been carried out, examining a wide range of retail foods of different brand names and including yogurts, creams, salads, coleslaws, soft cheeses, margarines, hot and cold beverages from dispensing machines, spreads, fresh and cooked meats, candied fruits, fresh strawberries, and take-away ‘fast’ foods. Analysis by headspace gas chromatography of styrene levels in the plastic containers showed levels of monomer ranging from 16 to 1300 mg kg^?1 although the majority of containers (73%) had styrene levels in the range 100–500 mg kg^?1 and only five plastic tubs had levels exceeding 1000 mg kg^?1. Analysis of the food contents of the plastic containers by automated headspace gas chromatography with single ion monitoring mass spectrometric detection showed levels of the monomer ranging from < 1 μg kg^?1 to 200 μg kg^?1, although the majority of foods (77%) had styrene levels below 10 μg kg^?1, and 26% of the total number analysed had levels below 1 μg kg^?1.     

Survey of the histamine content in fish samples randomly selected from the Greek retail market

The histamine content of fish sold in the Greek retail market was surveyed and the performance of high-performance liquid chromatography (HPLC) and enzyme-linked immunoabsorbant assay (ELISA) methods for the determination of histamine were compared. A total of 125 samples of fresh and canned tuna, fresh and canned sardines, deep frozen swordfish, smoked and deep frozen mackerel, anchovies, salted and smoked herring were analysed by HPLC (55 samples), ELISA (106 samples) and both methods (36 samples). Histamine levels as determined by HPLC, ranged from 2.7 mg kg^?1 to 220 mg kg^?1. The highest histamine concentrations obtained by HPLC were found in herring and anchovy samples. Eight out of the 55 samples (14.5%) analysed by HPLC, exceeded the US Food and Drug Administration (USFDA) limit (50 mg kg^?1), while 16 out of the 106 samples (15%) analysed by ELISA exceeded the limit. The results show that for histamine concentrations below 50 mg kg^?1, there is good agreement between the ELISA and HPLC but above 50 mg kg^?1 big differences were found.     

Occurrence and infant exposure assessment of nitrates in baby foods marketed in the region of Lisbon,Portugal

Commercial baby food labelled as from organic or conventional origin, including vegetable-based baby foods, fruit purees and fruit juices (n?=?80), were analysed for nitrate content by an in-house validated HPLC method. Nitrate contents ranged from 5 to 230?mg?kg^?1 with a mean concentration of 102?mg?kg^?1 for vegetable-based baby foods, and a median of 5?mg?kg^?1 for both fruit purees and juices. One sample of vegetable-based baby food was higher than the legislated value (200?mg?kg^?1). There were no significant differences between average nitrate levels in analysed samples regarding both farming systems. The estimated nitrate intake through baby foods for a mean nitrate concentration of 47?mg?kg^?1 ranged between 0.5 (15% of ADI) and 1.3?mg?kg^?1?bw?day^?1 (35% of ADI). The ADI level was exceeded (107–146% of ADI) only for the 95th and 99th percentiles of nitrate concentration.     

Influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing

BACKGROUND: This paper presents a multivariate approach to investigate the influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing. Four spring and two winter barley varieties were grown in one location in southern Europe. Moreover, one of the spring varieties was infested with sunn pest, in order to study the effects of this pest on malting quality, and subjected to different nitrogen fertilisation timing regimes. The samples were micromalted, mashed, brewed and analysed. RESULTS: The data showed that even though the two winter barleys seemed to be the best regarding their physical appearance (sieving fraction I + II > 82%), this superiority was not confirmed in the malt samples, which showed low values of Hartong extract (27.1%) and high values of pH (6.07–6.11) and β‐glucan content (12.5–13.2 g kg^?1), resulting in low‐quality beers. The barley sample subjected to postponed fertilisation had a total nitrogen content (19.5 g kg^?1 dry matter) exceeding the specification for malting barley and gave a beer with a low content of free amino nitrogen (47 mg L^?1) and high values of viscosity (1.99 cP) and β‐glucan content (533 mg L^?1). The beer obtained from the barley sample subjected to pest attack had good quality parameters. CONCLUSION: All spring barleys gave well‐modified malts and consequently beers of higher quality than the winter barleys. Moreover, postponed fertilisation was negatively related to the quality of the final beer, and sunn pest infestation did not induce important economic losses in the beer production chain. Copyright © 2010 Society of Chemical Industry     

Multimycotoxin and fungal analysis of maize grains from south and southwestern Ethiopia

The natural occurrence of fungi, mycotoxins and fungal metabolites was investigated in 100 samples of maize grains collected from south and southwestern Ethiopia in 2015. The maize samples were contaminated by Fusarium, Aspergillus and Penicillium species. Using liquid chromatography tandem mass spectrometry 127 secondary metabolites were analysed. Zearalenone was the most prevalent mycotoxin, occurring in about 96% of the samples. Zearalenone sulfate was the second most prevalent, present in 81% of the samples. Fumonisin B1 was detected in 70% of the samples with a mean level of 606 μg kg^?1 in positive samples, while FB2, FB3 and FB4 were detected in 62%, 51% and 60% of the maize samples with mean levels of 202, 136 and 85 μg kg^?1, respectively. Up to 8% of the samples were contaminated with aflatoxins, with a maximum level of aflatoxin B1 of 513 μg kg^?1. Results were higher than earlier reports for maize from Ethiopia.     

Impact of agronomic and climatic factors on the mycotoxin content of harvested oats in the United Kingdom

ABSTRACT

A survey was conducted to determine the concentration of Fusarium mycotoxins in UK oats over three seasons (2006–8). One hundred oat samples were collected each year at harvest, together with agronomic details, and analysed for 10 Fusarium mycotoxins. The incidence and concentration of most Fusarium mycotoxins, including deoxynivalenol and zearalenone, were relatively low in oats compared with values previously reported for wheat. HT-2 toxin (HT2) and T-2 toxin (T2) levels were relatively high with an overall combined (HT2+T2) mean of 450 μg kg^?1 for 2006–8. Data were combined with a previous dataset collected from 2002–5 to determine the effects of agronomic practices and climate. There was a negative relationship with late summer rainfall, indicating that drier conditions in July and August resulted in increased HT2 and T2 in UK oats. Agronomic factors that impacted upon HT2 and T2 in harvested oats were previous crop, cultivation, and variety. Analysis of the previous cropping history showed there was a stepwise increase in HT2+T2 as the cereal intensity of the rotation increased. Variety was an important factor, with higher levels and a wider range detected on winter versus spring varieties. Indicative levels for HT2 and T2 in cereals and cereal products were introduced by the EC in 2013. The indicative level for unprocessed oats for human consumption is a combined concentration (HT2+T2) of 1000 μg kg^?1. From 2002 to 2008, between 1% and 30% of samples exceeded 1000 μg kg^?1 HT2+T2 each year (overall mean, 16%). The introduction of European legislation on HT2 and T2 mycotoxins could have serious implications for UK oat production and oat-processing industries based on the levels detected within these studies.     

Household dietary exposure to aflatoxins from maize and maize products in Kenya

Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analysed for aflatoxin contamination. The samples were quantitatively analysed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modelled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18 and 480 μg kg^–1, 20% of muthokoi at between 12 and 123 μg kg^–1, and 35% of maize meal at between 6 and 30 μg kg^–1. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg^?1 body weight day^?1, while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 and 27 ± 154 ng kg^?1 body weight day^?1 respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.     

Survey of phthalate levels in Italian oily foods contained in glass jars with PVC gaskets

A method based on gas chromatography/tandem mass spectrometry was used to assess levels of twelve phthalates in 50 samples of oily foods packed in glass jars with metal closure obtained from a retail market. The amounts of di-methyl phthalate, di-ethyl phthalate, di-propyl phthalate, di-butyl phthalate, di-pentyl phthalate, benzyl butyl phthalate, di-cyclohexyl phthalate, di-n-octyl phthalate, di-isononyl phthalate and di-isodecyl phthalate in all samples analysed were less than the limit of quantification (LOQ). Di-(2-ethylhexyl) phthalate was detected in 20 samples in the range from 0.1 to 6 mg kg^?1 with an average of 1.0 mg kg^?1, and it exceeded the specific migration limit (SML) of 1.5 mg kg^?1 in five cases with an average of 3.0 mg kg^?1. Di-isobutyl phthalate was found in four samples at 0.1–0.4 mg kg^?1. The PVC gaskets used for the lids were negative for all tested phthalates, suggesting that the contamination of the foods originated from other sources, e.g. olive oil.     

Factors associated with fumonisin contamination of maize in Uganda

BACKGROUND: During production and handling, maize is attacked by many Fusarium species, some of which are prolific producers of fumonisins. Contamination of maize with fumonisins is influenced by climate, agronomic and postharvest practices. This study investigated the factors associated with the occurrence of fumonisins in maize produced in three agroecological zones of Uganda. RESULTS: All the maize samples were positive for fumonisins with levels ranging from 0.27 to 10 mg kg^?1. A positive and significant correlation (P < 0.01) was observed between fumonisin levels and agroecological zone. Maize from high altitude zone had significantly higher (P < 0.05) mean total fumonisin content (4.93 mg kg^?1) than maize from the mid altitude‐moist (4.53 mg kg^?1) and mid altitude‐dry (4.50 mg kg^?1) zones. Five farmer practices, namely intercropping, crop rotation, delayed harvesting, drying maize on bare ground and planting treated seeds were significantly associated with fumonisin production in maize. Intercropping, delayed harvesting and drying maize on bare ground increased fumonisin contamination whereas crop rotation and planting treated seeds reduced the contamination. CONCLUSION: All maize samples obtained from the three agroecological zones were contaminated with fumonisins. The study showed that some of the farmers' practices predispose maize to fumonisin contamination. The findings are important for future studies aimed at designing strategies to control and prevent contamination of maize with fumonisins. Copyright © 2009 Society of Chemical Industry     

Co-occurrence of fumonisins with aflatoxins in home-stored maize for human consumption in rural villages of Tanzania

This study determined maize-user practices that influence the presence of fumonisin and aflatoxin contamination of maize in food consumed in the rural areas of Tanzania. Samples of the 2005 maize harvest in Tanzania were collected from 120 households and examined for fumonisins and aflatoxins. Information on whether the maize was sorted to remove defective (visibly damaged or mouldy) maize before storage and whether the damaged and mouldy maize or the non-dehulled maize was used as food was also collected. In addition, the percentage of defective kernels in the samples was determined. Ninety per cent of the households sorted out defective maize, 45% consumed the defective maize and 30% consumed non-dehulled maize. In 52% of the samples fumonisins were determined at levels up to 11,048 µg kg^?1 (median = 363 µg kg^?1) and in 15% exceeded 1000 µg kg^?1; the maximum tolerable limit (MTL) for fumonisins in maize for human consumption in other countries. Aflatoxins were detected in 18% of the samples at levels up to 158 µg kg^?1 (median = 24 µg kg^?1). Twelve per cent of the samples exceeded the Tanzanian limit for total aflatoxins (10 µg kg^?1). Aflatoxins co-occurred with fumonisins in 10% of the samples. The percentage defective kernels (mean = 22%) correlated positively (r = 0.39) with the fumonisin levels. Tanzanians are at a risk of exposure to fumonisins and aflatoxins in maize. There is a need for further research on fumonisin and aflatoxin exposure in Tanzania to develop appropriate control strategies.     

Assessment of average exposure to organochlorine pesticides in southern Togo from water,maize (Zea mays) and cowpea (Vigna unguiculata)

Drinking water, cowpea and maize grains were sampled in some potentially exposed agro-ecological areas in Togo and analysed for their contamination by some common organochlorine pesticides. A total of 19 organochlorine pesticides were investigated in ten subsamples of maize, ten subsamples of cowpea and nine subsamples of drinking water. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatography-mass spectrometry (GC/MS). Estimated daily intakes (EDIs) of pesticides were also determined. Pesticides residues in drinking water (0.04–0.40 µg l^?1) were higher than the maximum residue limit (MRL) (0.03 µg l^?1) set by the World Health Organization (WHO). Dieldrin, endrin, heptachlor epoxide and endosulfan levels (13.16–98.79 µg kg^?1) in cowpea grains exceeded MRLs applied in France (10–50 µg kg^?1). Contaminants’ levels in maize grains (0.53–65.70 µg kg^?1) were below the MRLs (20–100 µg kg^?1) set by the Food and Agriculture Organization (FAO) and the WHO. EDIs of the tested pesticides ranged from 0.02% to 162.07% of the acceptable daily intakes (ADIs). Population exposure levels of dieldrin and heptachlor epoxide were higher than the FAO/WHO standards. A comprehensive national monitoring programme on organochlorine pesticides should be undertaken to include such other relevant sources like meat, fish, eggs and milk.     

Melamine contamination in milk powder in Uruguay

Forty samples of milk powder purchased in Uruguay were analysed to assess melamine (MEL) levels. Trichloroacetic acid and acetonitrile were used to extract and precipitate milk proteins previously to clean up of the samples by solid-phase extraction and then were determined by liquid chromatography coupled to ultraviolet detection. The limit of detection (LOD) and limit of quantification (LOQ)of MEL were 0.006 and 0.019 mg kg^?1, respectively. Milk was fortified with MEL at three levels, producing average recoveries higher than 83.8%. The values for positive samples ranged from 0.017 to 0.082 mg kg^?1. Nine samples were positive. Three of them had concentrations between LOD and LOQ. The mean MEL contamination was 0.028 mg kg^?1. Consumption of milk powder containing these levels of MEL does not constitute a health risk for consumers.