Deoxynivalenol in barley samples from Uruguay

Dietary Intake of Mycotoxin Susceptible Foods by Brazilian Nursing Mothers

Background:

The human milk has several health benefits to the mother and child, and it is the ideal form of nutrition for infants. However, some food contaminants such as mycotoxins can be transferred from the mother to the child through breast milk.

Objective:

To access the dietary intake of mycotoxin susceptible foods by nursing mothers.

Methods:

The dietary intake of mycotoxin susceptible foods was investigated by interviewing nursing mothers (n = 86), who were registered donors of the Human Milk Bank (HMB) of Blumenau (Brazil), through a food frequency questionnaire (FFQ). The mothers were contacted and those who agreed to answer the FFQ were recruited for the study group. The interview was conducted individually, face to face with each mother, by a trained researcher. The FFQ was divided into three food Groups (vegetables, animal and beverages, respectively), considered most prone to mycotoxins contamination. Socio-demographic characteristics of the mothers were also obtained.

Results:

The FFQ revealed a high weekly intake of foods susceptible to fungi and mycotoxin contamination. Consumption of wheat, coffee and cow’s milk was reported by 52, 44 and 51% of the mothers, respectively. The consumption of those foods occurred daily to more than 7 times per week.

Conclusion:

The study revealed that Brazilian nursing mothers frequently consume foods susceptible to mycotoxin contamination, especially wheat and its by-products. Brazilian health, environmental and agriculture authorities should pay permanent attention by applying monitoring programs to grains and cereals - both imported and domestically produced - as they are highly susceptible to fungi and mycotoxin contamination, which can be transferred to infants via breastfeeding, apart from harming the general population health.

Deoxynivalenol in wheat from the Northwestern region in China

Because of global warming and changes in farming systems, Fusarium head blight has gradually spread towards high-latitude regions such as Northwestern China. A survey was conducted to assess the prevalence and concentration of deoxynivalenol (DON) in wheat harvested during 2013 from the Shaanxi, Ningxia, Gansu, and Xinjiang provinces in China. DON concentration in 181 wheat samples was analysed by high-performance liquid chromatography combined with ultraviolet detection. Of the wheat samples, 82.9% were contaminated with DON, with a mean DON concentration of 500 μg/kg. According to the Chinese standard limits for DON, 10% of the positive samples were above the maximum limit of 1000 μg/kg. Regions with higher humidity showed higher levels of DON in the wheat samples. These results show the necessity of raising awareness of DON contamination in people from Northwestern China to protect their health from the risk of exposure to DON.

Natural Contamination with Mycotoxins Produced by Fusarium graminearum and Fusarium poae in Malting Barley in Argentina

Two of the most common species of toxin-producing Fusarium contaminating small cereal grains are Fusarium graminearum and F. poae; with both elaborating diverse toxins, especially deoxynivalenol (DON) and nivalenol (NIV), respectively. The objective of our work during the 2012-2014 growing seasons was to screen crops for the most commonly isolated Fusarium species and to quantify DON and NIV toxins in natural malting-barley samples from different producing areas of Argentina. We identified 1180 Fusarium isolates in the 119 samples analyzed, with 51.2% being F. graminearum, 26.2% F. poae and 22.6% other species. We found high concentrations of mycotoxins, at maximum values of 12 μg/g of DON and 7.71 μg/g of NIV. Of the samples, 23% exhibited DON at an average of 2.36 μg/g, with 44% exceeding the maximum limits (average of 5.24 μg/g); 29% contained NIV at an average of 2.36 μg/g; 7% contained both DON and NIV; and 55% were without DON or NIV. Finally, we report the mycotoxin contamination of the grain samples produced by F. graminearum and F. poae, those being the most frequent Fusarium species present. We identified the main Fusarium species affecting natural malting-barley grains in Argentina and documented the presence of many samples with elevated concentrations of DON and NIV. To our knowledge, the investigation reported here was the first to quantify the contamination by Fusarium and its toxins in natural samples of malting barley in Argentina.

Mycotoxins and beer. Impact of beer production process on mycotoxin contamination. A review

Beer is the most consumed alcoholic beverage in the world. Its contamination with mycotoxins is of public health concern, especially for heavy drinkers. Beer production implies a variety of operations which might impact the initial level of mycotoxins in a positive or negative way. The complexity of these operations do not give to the brewer a complete control on chemical and biochemical reactions that take place in the batch, but the knowledge about mycotoxin properties can help in identifying the operations decreasing their level in foodstuffs and in the development of mitigation strategies. This review discusses available data about mycotoxin evolution during malting and brewing process. The operations that may lead to a decrease in mycotoxin load are found to be steeping, kilning, roasting, fermentation and stabilization operations applied over the process (e.g. clarification). Also, other general decontamination strategies usually employed in food industry, such as hot water treatment of barley, ozonation or even the use of lactic acid bacteria starter cultures during malting or fermentation are considered.

Correlation of rainfall and levels of deoxynivalenol in wheat from Uruguay, 1997-2003

A total of 286 wheat samples for human consumption collected during 1997-2003 from four wheat-producing localities of south-western Uruguay were screened for deoxynivalenol (DON). Quantification was carried on by an immunochemical method using immunoaffinity columns and fluorimetric detection. The incidence of DON was high during the whole survey (58.5-100%), except in 1998 and 1999 in which no contamination occurred. During 2001 and 2002, 100% of samples contained detectable levels of DON, being the mean DON contents 6593 and 5880 µg kg(-1), respectively. The annual maximum levels ranged from 8800 to 11,400 µg kg(-1). A positive correlation between DON levels and precipitation was seen. The 70% of wheat samples destined for human consumption were contaminated with DON. To avoid the introduction of contaminated materials into the food chain process, the adoption of regular screening of the DON level in wheat is recommended, particularly in years with heavy rainfall during the flowering-to-early stages of grain maturity months.

Occurrence and intake of deoxynivalenol in cereal-based products marketed in Korea during 2007-2008

The occurrence of deoxynivalenol (DON) was investigated in 514 cereal-based products (corn-based, n = 125; barley-based, n = 96; wheat-based, n = 94; rice-based, n = 199) marketed in Korea during 2007-2008, and estimates of DON intake were determined. Samples were analysed by high-performance liquid chromatography (HPLC) with ultraviolet light (UV) detection after immunoaffinity clean-up. The limits of detection (LOD) and limits of quantification (LOQ) were 2.2 and 5.6 µg kg(-1), respectively. Recoveries and repeatability expressed as coefficients of variation (CV) were 82.3-100% and 2.4-15.3% in beer, bread and dried corn. The incidences and mean levels of DON were 56% and 68.9 µg kg(-1) for corn-based products, 49% and 24.1 µg kg(-1) for wheat-based products, 43% and 7.5 µg kg(-1) for barley-based products, and 16% and 3.4 µg kg(-1) for rice-based products, respectively. The estimated daily intake of DON from the consumption of rice-based, wheat-based, barley-based and corn-based products were 0.0038 µg kg(-1) bw day(-1), 0.0032 µg kg(-1) bw day(-1), 0.0015 µg kg(-1) bw day(-1) and 0.0002 µg kg(-1) bw day(-1), respectively. These values represent 0.38%, 0.32%, 0.25% and 0.01% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg kg(-1) bw day(-1). These results indicate that rice-based products are major contributors to DON exposure in Korea, even though the current exposure level is unlikely to cause adverse health effects.

Natural occurrence of deoxynivalenol and zearalenone in wheat from Jiangsu province, China

A three-year (2010-2012) survey was conducted to assess the prevalence and concentrations of deoxynivalenol (DON) and zearalenone (ZEN) in wheat from several regions of Jiangsu province, China, which are heavily impacted by Fusarium head blight. A total of 180 wheat samples were obtained from the infected fields that spread 21 counties. DON and ZEN levels were determined by liquid chromatography-mass spectrometry (LC-MS/MS). DON was found in 74.4% of samples at levels ranging from 14.52 to 41157.13 μg/kg (mean 488.02 μg/kg), while ZEN was found in 12.8% of samples at levels ranging from 10.13 to 3048.88 μg/kg (mean 73.04 μg/kg). In years and regions of higher rainfall, DON and ZEN levels were higher in samples. These results are necessary to take a vigilant attitude to prevent human intake of trichothecenes and protect human's health from the risk of exposure to these toxins.

Natural co-occurrence of aflatoxins and deoxynivalenol in poultry feed in Pakistan

Two hundred and fifteen broiler poultry feed samples were analysed over the time period of one year for the co-occurrence of aflatoxins and deoxynivalenol (DON). These were determined by GC-MS and ELISA, respectively. LOD values for aflatoxins and DON were 0.5 and 5 µg/kg, respectively. From all investigated 215 poultry feed samples, aflatoxins and DON co-occurred in 100 samples (46%). DON was detected in 114 samples while 100 samples also were positive for aflatoxins. Mean concentrations of positive samples for aflatoxins and DON were 18 and 807 µg/kg, respectively. Twenty-one DON-positive and 42 aflatoxin positive samples were contaminated above the EU maximum legal limits of 1000 µg/kg and 20 µg/kg, respectively. The present study provided useful data on aflatoxin and DON contamination, which may be helpful for future strategies to control contamination and to formulate standards in poultry feeds.

Genotyping and phenotyping of Fusarium graminearum isolates from Germany related to their mycotoxin biosynthesis

Fusarium graminearum is the most important pathogen causing Fusarium head blight (FHB) of small cereal grains worldwide responsible for quantitative and qualitative yield losses. The presence in crops is often associated with mycotoxin contamination of foodstuff limiting its use for human and animal consumption. A collection of isolates of F. graminearum from Germany was characterized genetically and chemically for their potential to produce the B trichothecenes deoxynivalenol (DON) and nivalenol (NIV). Molecular methods with eight PCR assays were implemented based on functional Tri7 and Tri13 genes and on the tri5-tri6 intergenic region to differentiate between chemotaxonomic groups DON and NIV, resulting in a marked majority (61/63) of DON chemotypes. Mycotoxins produced on rice kernels were quantified by means of LC-MSMS including DON, NIV, 3-acetyl-DON (3-ADON), 15-acetyl-DON (15-ADON), DON-3-glucoside, fusarenon X, as well as zearalenone; all of them proving to be present in high concentration among the isolates. All DON-chemotype isolates also produced lower amounts of NIV with the amount being positively correlated (R²=0.89) to the DON amount. 15-ADON and 3-ADON are reported to be produced simultaneously by the isolates, the former dominating over the latter in all but one isolate. Fungal biomass, was quantified via ergosterol amount on rice. It was used to calculate specific mycotoxin production per biomass of isolates, ranging from 0.104 to 1.815mg DON mg-1 ergosterol, presenting a Gaussian distribution. Genotype and phenotype characterization revealed discrepancies with respect to mycotoxin production potential of the fungi, i.e. isolates from one chemotype were able to produce mycotoxins from other chemotypes in considerable amounts.

Molecular survey of trichothecene genotypes of Fusarium graminearum species complex from barley in southern Brazil

Fusarium head blight is a disease of primary concern to small-grain cereals of Brazil, including barley. Its main causal agent, Fusarium graminearum species complex (Fg complex)¸ is able to produce mycotoxins, especially deoxynivalenol (DON) and nivalenol (NIV), that usually contaminate grain. Strains that produce DON may also produce its acetylated derivatives: 3-acetyl-DON (3-ADON) and 15-acetyl-DON (15-ADON). Ninety two isolates were obtained from samplings of barley grain during three years (2007, 2008 and 2009) from several fields in both southern and northern production regions of Rio Grande do Sul state, Brazil. These isolates were examined for polymerase chain-reaction-based (PCR) trichothecene genotype based on the amplification of portions of Tri3 and Tri12. There was no effect of year or region on the proportion of trichothecene genotypes. Overall, 66% of the strains (61/92) were 15-ADON, 4.4% (4/92) were 3-ADON and 29.3% (27/92) were NIV. The overall NIV/DON ratio estimated (0.41) was five times higher than that found in previous studies with strains from wheat grown in the same region. Species identification of nine strains representing the trichothecene genotypes, based on comparisons of DNA sequences of portions of the PHO, RED and URA genes with sequences from curated reference isolates of Fusarium from GenBank, revealed that they belong to F. graminearum sensu stricto (four 15-ADON and one 3-ADON strain), F. meridionale (three NIV strains) and F. austroamericanum (one 3-ADON strain). These results add to the current regional knowledge of trichothecene genotypes and species within the Fg complex affecting barley in the region.

Fumonisins, trichothecenes and zearalenone in cereals

Fumonisins are phytotoxic mycotoxins which are synthesized by various species of the fungal genus Fusarium such as Fusarium verticillioides (Sacc.) Nirenberg (ex F.moniliforme Sheldon) and Fusarium proliferatum. The trichothecene (TC) mycotoxins are secondary metabolites produce by species that belong to several fungal genera, especially Fusarium, Stachybotrys, Trichothecium, Trichoderma, Memnoniella and Myrothecium. Fusarium mycotoxins are widely dispersed in cereals and their products. Zearalenone (ZEA) is an estrogenic compound produced by Fusarium spp. such as F. graminearum and F. culmorum. Fumonisins, the TCs and ZEA are hazardous for human and animal health. Contamination with TCs causes a number of illnesses in human and animal such as decrease in food consumption (anorexia), depression or inhibition on immune system function and haematoxicity. The purpose of this paper is to give a review of the papers published on the field of fumonisin, TC and ZEA mycotoxins in cereals consumed in the world.

Detection of deoxynivalenol contamination in wheat products in Thailand

A total of ninety samples in three kinds of wheat products (30 noodle, 30 bread, and 30 cereal samples) were collected from the supermarkets in Bangkok, Thailand, from February to April 2007. The occurrence of deoxynivalenol (DON) contamination in wheat products was investigated using high-performance liquid chromatography equipped with a UV light detector. The extraction method was performed using a multifunctional cleanup column. The limit of quantification was 0.10 microg x g(-1) from the range obtained in a linear calibration. The survey found almost 94% of the DON-contaminated samples below 1 microg x g(-1), which corresponds to the U.S. Food and Drug Administration advisory level. DON was detected in 18.9% (17 of 90) of all samples, in 6.67% (2 of 30) and 16.67% (5 of 30) of noodle and bread samples at levels from 0.17 to 0.35 and 0.14 to 1.13 microg x g(-1), respectively, while it was in 33.33% (10 of 30) of cereal samples at levels from 0.13 to 0.39 microg x g(-1). The results suggest that the exposure to DON from the consumption of wheat products, especially noodles, bread, and cereal, is at a very low risk level.