Mycotoxin contamination of food in Europe: Early detection and prevention strategies

The influence of different abiotic conditions on the concentrations of free and conjugated deoxynivalenol and zearalenone in stored wheat

Environmental factors influence fungal growth and mycotoxin production in stored grains. However, the concentrations of free mycotoxins and their conjugates and how they are impacted by different interacting environment conditions have not been previously examined. The objectives of this study were to examine the impact of storage conditions (0.93-0.98 aw) and temperature (20-25 °C) on (a) the concentrations of deoxynivalenol and zearalenone and their respective glucosides/conjugates and (b) the concentrations of emerging mycotoxins in both naturally contaminated and irradiated wheat grains inoculated with Fusarium graminearum. Contaminated samples were analysed for multiple mycotoxins using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Method validation was performed according to the acceptable performance criteria set and updated by the European Commission regulations No. 2021/808/EC. As an important conjugate of deoxynivalenol, the concentrations of deoxynivalenol-3-glucoside were significantly different from its precursor deoxynivalenol at 0.93 aw (22% moisture content- MC) at 25 °C in the naturally contaminated wheat with a ratio proportion of 56:44% respectively. The high concentrations of deoxynivalenol-3-glucoside could be influenced by the wheat's variety and/or harvested season/fungal strain type/location. Zeralenone-14-sulfate concentrations were surprisingly three times higher than Zearalenone in the naturally contaminated wheat at 0.98 aw (26% MC) at both temperatures. Emerging mycotoxins such as moniliformin increased with temperature rise with the highest concentrations at 0.95 aw and 25 °C. These findings highlight the influence and importance of storage aw x temperature conditions on the relative presence of free vs conjugated mycotoxins which can have implications for food safety.

Assessing wineries' performance in managing critical control points for arsenic, lead, and cadmium contamination risk in the wine-making industry: A survey-based analysis utilizing performance indicators as a results tool

Human health hazards appear in wine production. Wineries have implemented food safety management systems to control food hazards through Hazard Analysis Critical Control Point (HACCP). Wine-making industry applies HACCP by evaluating Critical Control Points (CCPs). One of the CCPs that exhibits inadequate control is the potential contamination risk of arsenic, cadmium, and lead throughout the winemaking procedure. Wineries performance level about controlling CCPs related to contamination risk by arsenic, cadmium and lead in the winemaking were analyzed. A sixteen-question questionnaire was made to achieve this research. Three indicators were calculated for training, legislation, and analysis performance components in CCPs control. Results revealed that wineries fault in analysis and legislation components. Identification and updating of legislation about As, Cd and Pb contamination risk is in starting performance level for wineries that produce less than 250,000 L/year wineries. Analysis performance level is even lower than legislation. Only one out of every three wineries possess information regarding the concentrations of arsenic, cadmium, and lead in the soils of vineyards where grapes are cultivated. Furthermore, the availability of data on their available concentrations in the soil solution is even more limited. Those wineries that controlled As, Cd and Pb concentrations make it according to official recommendations using techniques based on atomic absorption spectrometry. However, there is a lack of this spectrometry equipment in the wineries own laboratories.

Characterization and Antifungal Activity of Pullulan Edible Films Enriched with Propolis Extract for Active Packaging

Active pullulan films with the addition of 3, 5 or 10% propolis extract produced by the casting method were tested in the study. Propolis extracts from Bochnia County, Siedlce County and Ełk County (Poland) were used. The appearance of the films was characterized, as well as physical parameters (thickness, moisture content, water solubility), tensile strength (TS), elongation at break (EB), optical characteristics (light transparency, UV barrier, color) and antifungal properties. The antifungal activity of the films was tested by the disc diffusion method against yeast (Candida albicans, C. krusei, Saccharomyces cerevisiae, Rhodotorula mucilaginosa) and mold (Alternaria solani, Fusarium solani, Rhizopus stolonifer, Colletotrichum gloeosporioides, C. cladosporioides, Aspergillus niger, A. ochraceus, Mucor mucedo, Penicillium expansum, P. chrysogenum). The origin of propolis influenced the color and water solubility of the films. The addition of increasing concentrations of propolis extract increased the film thickness and the intensity of the yellow color, extended the water dissolution time of the film and reduced the values of TS and EB. The addition of propolis extract in the pullulan film improved UV radiation protection but decreased light transparency. The antifungal activity increased significantly with the increasing concentration of propolis extract in the film, regardless of the origin of propolis. Molds showed greater sensitivity to pullulan films containing propolis extract than yeasts. In general, films made of pullulan with the addition of propolis extract can be considered as natural active packaging to protect against the growth of fungi in food.

An Evaluation of Food Safety Performance in Wineries

Wine production has food safety hazards. A Hazard Analysis Critical Control Point (HACCP) system makes it possible to identify, evaluate, and control significant food safety hazards throughout the wine production process. The Prerequisites Programs (PPRs) and HACCP performance in Protected Denomination of Origin “Vinos de Madrid” wineries were analyzed. Winery performances were evaluated for every critical control point (CCPs) in each winemaking process stage, including their implementation of PPR and HACCP principles. This study was developed through a survey of 55 questions divided into 11 sections, and it was conducted on a sample of 21 wineries. The results revealed that the CCPs worst performance level are for the control of metals (Cd, Pb, As) in grapes and fungicides or pesticide control in the harvest reception. A total of 91.5% of the wineries had implemented a prerequisites program (PPRs), regardless of their annual wine production. However, there was variability in the type of prerequisite plans, training, level of knowledge of operators, and annual budget allocation. Three out of four wineries had an HACCP, although corrective action procedures and verification procedures had the lowest and the worst HACCP practical implementation. The significant barriers for HACCP performance in wineries are linked with a lack of food safety staff training, low involvement of all staff in food safety tasks, and poor application of CCP chemical and microbiologic control methods.

Computational Strategy for Minimizing Mycotoxins in Cereal Crops: Assessment of the Biological Activity of Compounds Resulting from Virtual Screening

Cereal crops are frequently affected by toxigenic Fusarium species, among which the most common and worrying in Europe are Fusarium graminearum and Fusarium culmorum. These species are the causal agents of grain contamination with type B trichothecene (TCTB) mycotoxins. To help reduce the use of synthetic fungicides while guaranteeing low mycotoxin levels, there is an urgent need to develop new, efficient and environmentally-friendly plant protection solutions. Previously, F. graminearum proteins that could serve as putative targets to block the fungal spread and toxin production were identified and a virtual screening undertaken. Here, two selected compounds, M1 and M2, predicted, respectively, as the top compounds acting on the trichodiene synthase, a key enzyme of TCTB biosynthesis, and the 24-sterol-C-methyltransferase, a protein involved in ergosterol biosynthesis, were submitted for biological tests. Corroborating in silico predictions, M1 was shown to significantly inhibit TCTB yield by a panel of strains. Results were less obvious with M2 that induced only a slight reduction in fungal biomass. To go further, seven M1 analogs were assessed, which allowed evidencing of the physicochemical properties crucial for the anti-mycotoxin activity. Altogether, our results provide the first evidence of the promising potential of computational approaches to discover new anti-mycotoxin solutions

Study on the Sustainability Potential of Thyme, Oregano, and Coriander Essential Oils Used as Vapours for Antifungal Protection of Wheat and Wheat Products

This study aims to highlight the antifungal, antimicotoxigenic potential and phytotoxic effect of three essential oils (EOs) of Origanum vulgare (OEO), Thymus vulgaris (TEO), and Coriandrum sativum (CEO) on wheat storage, but also the impact of EOs treatment on the sensory properties of bakery products obtained from the wheat seeds. The chemical composition of EOs was determined using GC-MS analysis; the fungal load was evaluated using the direct plating technique, while mycotoxin analyses were conducted using enzyme-linked immunosorbent assay (ELISA). A selective antifungal effect has been highlighted in terms of the action of EOs vapours. OEO and TEO are inhibited Alternaria, Fusarium and Drechslera, while Saccharomyces and Cladosporium have proven to be the most tolerant fungi. Drechslera is the most sensitive, the effect of all EOs being a fungicidal one. However, the fungicidal effect proved present in all EOs applied as vapours with values ranging between 0.2–0.4%. Regarding the phytotoxic effect of EOs vapours on the germination of the seeds, TEO and OEO had an inhibitory effect, especially at 0.4%. The effect is cumulative over time. The EOs inhibited deoxynivalenol (DON) occurrence; the maximum percentage of inhibition was obtained after 21 days of vapours exposure, being more effective in the case of 0.2%. EOs vapours treatment does not affect the quality of bread obtained from treated wheat seeds from a sensory point of view.

Fungal species and mycotoxins in mouldy spots of grass and maize silages in Austria

Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method, the dominant cultivable fungi in mouldy grass silages (GS) (n = 19) and maize silages (MS) (n = 28) from Austria. The profiles of regulated, modified, and emerging mycotoxins together with other fungal metabolites were analysed via LC-(ESI)MS/MS. Penicillium roqueforti, Saccharomyces spp., Geotrichum candidum, Aspergillus fumigatus and Monascus ruber were the most frequent fungal organisms identified. Other species including Mucor circinelloides, Fusarium spp. and Paecilomyces niveus were detected at lower frequencies. The presence of complex mixtures of toxic and potentially toxic compounds was evidenced by high levels and occurrences (≥ 50%) of Penicillium-produced compounds such as mycophenolic acid (MPA), roquefortines (ROCs), andrastins (ANDs) and marcfortine A. Mouldy silages contained toxins commonly produced by genus Fusarium (e.g. zearalenone (ZEN) and trichothecenes), Alternaria (like tenuazonic acid (TeA) and alternariol (AHO)) and Aspergillus (such as sterigmatocystin (STC)). Compared to those in GS, mouldy spots in MS presented significantly higher fungal counts and more diverse toxin profiles, in addition to superior levels of Fusarium spp., Penicillium spp. and total fungal metabolites. Generally, no correlation between mould counts and corresponding metabolites was detected, except for the counts of P. roqueforti, which were positively correlated with Penicillium spp. metabolites in mouldy MS. This study represents a first assessment of the fungal diversity in mouldy silage in Austria and highlights its potential role as a substantial contributor to contamination with complex mycotoxin mixtures in cattle diets.

Knowledge and Behavioral Habits to Reduce Mycotoxin Dietary Exposure at Household Level in a Cohort of German University Students

Mycotoxins pose a health concern for humans. Therefore, strategies at pre- and post-harvest and maximum levels for food have been implemented, aimed to minimize the risk of dietary exposure. Yet, consumers’ dietary habits and life style play a substantial role in overall exposure. The aim of this study was to investigate knowledge of mycotoxins and accordance to behavioral practices or habits that may affect the risk of mycotoxin dietary exposure at the household level or when food commodities are obtained from non-regulated trade markets. For this purpose, an online survey was applied to a university student cohort (n = 186). The survey consisted of 23 questions grouped in five categories: Socio-demographic and income data, general life style and habits, knowledge about mycotoxins, compliance with the “17 golden rules to prevent mycotoxin contamination” of the German Federal Institute for Risk Assessment (BfR), and measures towards reducing health risks. We paid particular attention to knowledge and compliance of a group acquiring food items in markets outside regulation and surveillance, namely, adherents of food movements such as food sharing or dumpster diving. The results of our study indicate a generally rather low level of knowledge about mycotoxins in the investigated cohort, as well as a weak perception of their associated risks compared to similar studies; around half of the cohort was unfamiliar with the term “mycotoxin” and the health risks of mycotoxins were considered comparable to those of pesticides, heavy metals, microplastics and food additives. We observed, in general, a relatively high degree of compliance with the proposed golden rules. The rules with the highest compliance related to deteriorated foods with visible signs of fungal infestation, probably because these are already considered as food waste. Rules that were less followed included those that require a specific knowledge of food storage and early fungal contamination stages, namely preventive measures related to storage of bread. Adherents of food movements did not differ significantly with the control group in terms of knowledge, risk perception and compliance with the 17 golden rules. This may be due to the homogeneity of the cohort in terms of demography, age and educational level. However, significant low compliance in the food movements group was observed with the rules “Buy fruit and vegetables that are as intact as possible, i.e., without injuries and bruises” and “Rotten fruit should neither be eaten nor further processed into compote or jam”, possibly because of ideological convictions around reducing food waste. In conclusion, mycotoxin prevention strategies should not end at the retail level; in particular, clarification and information regarding health risk from mycotoxins are suggested in order to reduce the risk of exposure in private households or in informal trade markets. The results of this study should, however, be interpreted with caution due to the specific characteristics of the cohort in terms of age and educational level and the disparity in size between the control and the food movement group. This study is a starting point for evaluating and understanding the consumer perspective on mycotoxins.

Contamination of Wheat, Barley, and Maize Seeds with Toxigenic Fusarium Species and Their Mycotoxins in Tunisia

Background

Fusarium is a worldwide distributed fungal genus. It includes different species pathogenic to cereals among others crops. Some of these species can also produce toxic compounds toward animals and humans.

Objective

In this work, occurrence of fumonisins B1+B2, zearalenone, type A trichothecenes (T-2 and HT-2 toxins), and type B trichothecenes (deoxynivalenol[DON] and nivalenol[NIV]) was studied in 65 samples of stored and freshly harvested wheat, barley, and maize collected in Tunisia.

Methods

Mycotoxins analyses were performed by using gas chromatography for type B trichothecenes and HPLC for other mycotoxins. Obtained results were compared with the presence of mycotoxigenic species considered responsible for their synthesis by using species-specific polymerase chain reaction (PCR).

Results

Fumonisins occurred in 20.83% of wheat, 40% of barley, and 57.14% of maize samples, at levels exceeding European limits and suggesting a risk in Tunisian cereals, especially maize. Zearalenone, DON, NIV, and T-2+HT-2 toxins were detected at lower values in only wheat and barley samples. PCR protocols showed the predominance of F. verticillioides especially in maize, and occurrence of F. equiseti and F. graminearum in wheat and barley, and F. proliferatum in only two maize samples. A very consistent correlation was found between the detection of F. verticillioides and the contamination by fumonisins, as well as between the presence of F. graminearum and the contamination by zearalenone, DON, and NIV in the analyzed cereals.

Conclusions

Consequently, the detection of Fusarium species with the current PCR assays strategy in wheat, barley, and maize grains may be considered predictive of their potential mycotoxin risk in these matrices.

Highlights

This work is the first to report information on the occurrence of fumonisins, trichothecene, and ZEN, together with their potentially producing Fusarium species in wheat, barley, and maize in Tunisia. The high level of fumonisins in cereals, especially maize, stresses the importance of the control and the regularization of these mycotoxins for food safety.

Model of Fungal Development in Stored Barley Ecosystems as a Prognostic Auxiliary Tool for Postharvest Preservation Systems

Postharvest preservation and storage have a crucial impact on the technological quality and safety of grain. The important threat to stored grain quality and nutritional safety of cereal products is mould development and their toxic metabolites, mycotoxins. Models based on predictive microbiology, which are able to estimate the kinetics of fungal growth, and thus, the risks of mycotoxin accumulation in a mass of grain are promising prognostic tools that can be applied in postharvest management systems. The study developed a modelling approach to describe total fungal growth in barley ecosystems stored at different temperatures (T = 12–30 °C) and water activity in grain (aw = 0.78–0.96). As the pattern of fungal growth curves was sigmoidal, the experimental data were modelled using the modified Gompertz equation, in which constant coefficients reflecting biological parameters of mould development (i.e. lag phase duration (τlag), maximum growth rate (μmax) and the maximum increase in fungal population level (Δmaxlog(CFU)) were expressed as functions of storage conditions, i.e. aw and T. The criteria used to evaluate the overall model performance indicated its good precision (R2 = 0.95; RMSE = 0.23) and high prediction accuracy (bias factor and accuracy factor Bf = 1.004, Af = 1.035). The formulated model is able to estimate the extension of fungal contamination in a bulk of grain versus time by monitoring temperature and intergranular relative humidity that are readily measurable in practice parameters; therefore, it may be used as a prognostic support tool in modern postharvest management systems.

Antifungal Activity of Some Essential Oils Emulsions Against Fungi Contaminating Ras Cheese

<b>Background and Objective:</b> Ras cheese is one of the important dairy products that are consumed in great quantities. But this cheese is vulnerable to the growth of fungi during ripening and selling until consumption. Therefore, research aimed to detect fungi contaminating Ras cheese and try to resist them. <b>Materials and Methods:</b> The effect of various concentrations (0.25, 0.5, 1, 2 and 3%) of essential oils emulsions of clove (<i>Syzygium aromaticum</i>), thyme (<i>Thymus vulgaris</i>) and peppermint (<i>Mentha piperita</i>) severally on the mycelial growth of the isolated fungi as compared to the control sample was tested <i>in vitro.</i> <b>Results:</b> The results indicated that many fungal species belonging to the genera <i>Aspergillus</i>, <i>Mucor</i>, <i>Eurotium</i> and <i>Mortierella</i> were isolated from the infected Ras cheese. Ochratoxin A was found in two samples whereas recorded the highest level in sample number 1 (2.1 μg kg<sup>1</sup>). Aflatoxin M1 was found in few levels ranged between 0.012 and 0.360 μg kg<sup>1</sup>in cheese samples, while aflatoxin B1 and B2 weren't detected in all samples. Clove essential oil emulsion completely inhibited the growth of all tested fungi at the concentration of 0.5%, followed by thyme essential oil emulsion which inhibited the fungal growth of all fungi at the concentration of 1%, while peppermint essential oil emulsion was less effective. <b>Conclusion:</b> The research recommends that clove and thyme essential oils emulsions can be used to resist the fungi of Ras cheese. Also, suggests that more research could be done on these essential oils emulsions to produce safe foods free of fungi.

Farming System Effect on the Incidence of Aspergillus carbonarius on Kotsifali Grapes and Ochratoxin A Occurrence in Wines of Crete

ABSTRACT

During grape cultivation and wine production, the most effective way to prevent ochratoxin A (OTA) contamination of grapes and wine is to control ochratoxigenic fungal species, especially Aspergillus carbonarius, using appropriate cultivation techniques. In this study, the influence of an organic farming system (OFS) and an integrated farming system (IFS) on the incidence of A. carbonarius on grapes, and OTA contamination of wine, were examined. Mycological analysis of grapes collected from Kotsifali cultivar (Vitis vinifera L.) vineyards and grown under two farming systems (OFS and IFS) was performed over two growing seasons. For the same two growing seasons, OTA levels of representative wine samples from wineries located in the same area, made from the same cultivar (single varietal or covinificated with Mandilari), and grown under the two farming systems were determined. The results showed that the farming system had a significant influence on the incidence of A. carbonarius, with IFS being the most effective in the control of the fungus and the prevention of OTA occurrence in wine. This knowledge could offer viticulturists a useful tool to produce safer grapes, giving winemakers an incentive to make low-OTA wine.

HIGHLIGHTS

Diversity and ochratoxin A-fumonisin profile of black Aspergilli isolated from grapes in China

Aspergillus spp. are a common contaminant of grapes and a major source of mycotoxins. China is the largest producer of grape in the world now, however, the toxigenic Aspergillus population on grape in this country is still largely unknown. In this study, a total of 345 strains were isolated from grapes of 13 main grapevine producing regions in China. Based on calmodulin gene sequences, eight species within Aspergillus section Nigri were identified. Among them, Aspergillus tubingensis (48.7%) was predominant, followed by Aspergillus welwitschiae (20.6%) and Aspergillus aculeatinus (11%). Average of contamination level was up to 64.19%, and we found the occurrence of section Nigri species on the surface of fresh grapes was significantly influenced by the climate (P<0.05). The subtropical monsoon climate showed the highest fungal detection rate (72.45%), followed by the temperate monsoon climate (49.82%), and the lowest frequency was found in the temperate continental climate (37.23%). Regarding mycotoxin-producing capacity, 4.4% of the total tested section Nigri isolates (137) were positive for ochratoxin A (OTA) production and 59.6% were fumonisin B2 (FB2) producers. Of those, Aspergillus carbonarius was the main OTA producer and A. welwitschiae and Aspergillus niger were the main FB2 producers with different toxigenic ability. Our results highlight the potential risk of OTA and FB2 contamination by A. carbonarius and A. welwitschiae on grape in China, respectively; management strategies should be considered for preventing and reducing the toxigenic Aspergillus and its mycotoxins.

Several species of Penicillium isolated from chestnut flour processing are pathogenic on fresh chestnuts and produce mycotoxins

A collection of 124 isolates of Penicillium spp. was created by monitoring fresh chestnuts, dried chestnuts, chestnut granulates, chestnut flour and indoor chestnut mills. Sequencing of the ITS region, β-tubulin and calmodulin, macro-morphology and secondary metabolite production made it possible to determine 20 species of Penicillium. P. bialowiezense was dominant in the fresh chestnuts, while P. crustosum was more frequent in the other sources. A pathogenicity test on chestnut showed that around 70% of the isolates were virulent. P. corylophilum and P. yezoense were not pathogenic, while the other 18 species had at least one virulent isolate. P. expansum and P. crustosum were the most virulent. The isolates were characterized to establish their ability to produce 14 toxic metabolites in vivo: 59% were able to produce at least one mycotoxin. P. expansum was able to produce patulin, chaetoglobosin A and roquefortine, while P. bialowiezense produced C. Mycophenolic acid. Cyclopenins and viridicatins were produced by most of the P. crustosum, P. polonicum, P. solitum and P. discolour isolates. Some of the P. crustosum isolates were also able to produce roquefortine C or penitrem A. Information about the occurrence of Penicillium spp. and their mycotoxins will help producers to set up management procedures that can help to control the fungal growth and the mycotoxin production of chestnuts.

Analysis on Metabolic Functions of Stored Rice Microbial Communities by BIOLOG ECO Microplates

Microbial contamination has been a pervasive issue during the rice storage and triggers extensive researches. The metabolism of microorganisms was proved as an indicator to mirror the degree of microbial contamination. It is necessary to develop a scientific method to analyze the metabolism of rice microbial communities, thereby monitoring the microbial contamination. In this study, the metabolism of rice microbial communities in different storing-year were investigated by BIOLOG ECO microplates. The three rice samples were respectively stored for 1-3 years. The related indicators of BIOLOG ECO microplates were determined, including average well-color development (AWCD) of carbon sources and three metabolic functional diversity indices. The results showed that there were significant differences in the AWCD of all carbon sources among the three rice microbial communities (p < 0.05), and the functional diversity indices except Simpson index showed significant differences (p < 0.05). Additionally, the three rice microbial communities differed significantly in the metabolic utilization of carboxylic acids and miscellaneous (p < 0.05), and there were, however, no significant differences in the other four types of carbon sources. Furthermore, principal component analysis revealed that the microbial communities of stored rice had obviously different metabolic functions in different storage period. Therefore, the study indicated that the BIOLOG ECO microplate was applicable to evaluate the metabolic functions of rice microbial communities, and carboxylic acids and miscellaneous were two crucial parameters of carbon sources to identify the metabolic differences of microbial communities, a case in which it reflected the conditions of rice microbial contamination.

Impact of Mycotoxins Secreted by Aspergillus Molds on the Inflammatory Response of Human Corneal Epithelial Cells

Exposure to molds and mycotoxins not only contributes to the onset of respiratory disease, it also affects the ocular surface. Very few published studies concern the evaluation of the effect of mycotoxin exposure on ocular cells. The present study investigates the effects of aflatoxin B₁ (AFB₁) and gliotoxin, two mycotoxins secreted by Aspergillus molds, on the biological activity of the human corneal epithelial (HCE) cells. After 24, 48, and 72 h of exposure, cellular viability and inflammatory response were assessed. Both endpoint cell viability colorimetric assays and continuous cell impedance measurements, providing noninvasive real-time assessment of the effect on cells, were performed. Cytokine gene expression and interleukin-8 release were quantified. Gliotoxin appeared more cytotoxic than AFB₁ but, at the same time, led to a lower increase of the inflammatory response reflecting its immunosuppressive properties. Real-time cell impedance measurement showed a distinct profile of cytotoxicity for both mycotoxins. HCE cells appeared to be a well-suited in vitro model to study ocular surface reactivity following biological contaminant exposure. Low, but persistent inflammation, caused by environmental factors, such as fungal toxins, leads to irritation and sensitization, and could be responsible for allergic manifestations which, in turn, could lead to mucosal hyper-reactivity.

Biodiversity and ochratoxin A profile of Aspergillus section Nigri populations isolated from wine grapes in Cyprus vineyards

The objective of this study was to evaluate the biodiversity of Aspergillus section Nigri populations from Cyprus vineyards by morphological, toxigenic and phylogenetic analysis. Aspergillus section Nigri populations were isolated from grapes of the varieties 'Maratheftiko' and 'Cabernet Sauvignon' originating from six growing regions of Cyprus during 2010 and 2011 years. The isolation frequency of Aspergillus section Nigri from grape samples was 43.3% and a total of 284 isolates were selected for further analyses based on the macroscopic characteristics of black aspergilli. The isolates were characterized by sequencing analysis of the calmodulin gene in order to identify species responsible for ochratoxin A (OTA) production. The phylogenetic analysis showed that the isolates were grouped in three major clusters. The A. tubingensis cluster included 262 isolates (92.25%), the A. niger cluster included 15 isolates identified as A. niger (5.3%) and 6 isolates identified as A. welwitschiae (2.1%). One isolate was classified as A. carbonarius (0.35%) and was grouped in a cluster together with the reference isolates of A. carbonarius, A. sclerotioniger, A. sclerotiocarbonarius and A. ibericus. All the isolates were evaluated for their ochratoxigenic ability by HPLC coupled with a fluorescence detector (HPLC-FLD) and the positive isolates were re-examined using ultra high-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). The Aspergillus carbonarius isolate produced an average quantity of 1436.1 ng OTA/g Czapek Yeast Agar (CYA); From the A. niger strains three isolates (20%) produced OTA and only one isolate from A. welwitschiae (16.7%) was proved ochratoxigenic with toxin production average at 23.9 ng/g and 9.1 ng/g CYA respectively. Grape must samples derived from the collected berries were also analyzed for OTA and none of the samples were found contaminated with the mycotoxin. The results showed that the geographic area and the meteorological conditions had no significant effect on the incidence and the distribution of black aspergilli in this 2-year project. However, absence of rainfall and low humidity during the harvesting period were critical for the low incidence of the ochratoxigenic A. carbonarius on grapes.

Aflatoxins and ochratoxin A and their Aspergillus causal species in Tunisian cereals

Occurrence of aflatoxins (AFs) AFB1, AFB2, AFG1, AFG2 and ochra toxin A (OTA) was studied in 65 samples of stored and freshly harvested wheat, barley and maize collected in Tunisia. The mycotoxins were simultaneously extracted and quantified by high performance liquid chromatography. Determination of AF-producing (section Flavi) and OTA-producing Aspergillus species (sections Nigri and Circumdati) was conducted in these samples by species-specific polymerase chain reaction (PCR). Results showed that most of maize samples were contaminated with AFs, data after storage showing lower values than those collected at harvest. All contaminated maize samples contained AFG1 and AFG2, among which 27.78% also had AFB1 and AFB2. This AFs pattern was consistent with the A. parasiticus toxin profile. A. flavus however showed the highest frequency in maize but was also found in barley and wheat where no AFs were detected. In contrast, OTA was neither found in maize nor in barley and only one wheat sample contained OTA. A. niger was the only OTA-producing species detected.

Diversity of black Aspergilli isolated from raisins in Argentina: Polyphasic approach to species identification and development of SCAR markers for Aspergillus ibericus

Aspergillus section Nigri is a heterogeneous fungal group including some ochratoxin A producer species that usually contaminate raisins. The section contains the Series Carbonaria which includes the toxigenic species Aspergillus carbonarius and nontoxigenic Aspergillus ibericus that are phenotypically undistinguishable. The aim of this study was to examine the diversity of black aspergilli isolated from raisins and to develop a specific genetic marker to distinguish A. ibericus from A. carbonarius. The species most frequently found in raisins in this study were Aspergillus tubingensis (35.4%) and A. carbonarius (32.3%), followed by Aspergillus luchuensis (10.7%), Aspergillus japonicus (7.7%), Aspergillus niger (6.2%), Aspergillus welwitschiae (4.6%) and A. ibericus (3.1%). Based on inter-simple sequence repeat (ISSR) fingerprinting profiles of major Aspergillus section Nigri members, a sequence-characterized amplified region (SCAR) marker was identified. Primers were designed based on the conserved regions of the SCAR marker and were utilized in a PCR for simultaneous identification of A. carbonarius and A. ibericus. The detection level of the SCAR-PCR was found to be 0.01 ng of purified DNA. The present SCAR-PCR is rapid and less cumbersome than conventional identification techniques and could be a supplementary strategy and a reliable tool for high-throughput sample analysis.

Impact of postharvest processing on the fungal population contaminating African walnut shells (Tetracarpidium conophorum Mull. Arg) at different maturity stages and potential mycotoxigenic implications

African walnut (Tetracarpidium conophorum Mull. Arg) is commonly processed by boiling or toasting and consumed as a snack or used as a thickener in many West African soup preparations. The nuts are usually exposed to both high temperatures and high relative humidity in open markets which predisposes them to fungal growth. Hence, the dangers of spore inhalation and resultant mycosis cannot be over-emphasized as retailers and consumers are always in direct contact with these nuts during harvest, processing and consumption. So far, there is no reported research on potential mycotoxin contamination of African walnut and whether this risk might be accentuated by processing. African walnut, at early and late maturity stages, were processed by toasting, boiling or left unprocessed before being stored at 25°C and 37°C, respectively under controlled relative humidity for 7days. Nuts were cracked and shell pieces cultured in malt extract agar (MEA) and Dichloran Glycerol 18 (DG18) media and incubated at 25°C for 7days. Results revealed that potential mycotoxigenic species - Aspergillus section Nigri, Aspergillus flavus/parasiticus, Fusarium spp. and Penicillium spp. - were frequently isolated. When compared with unprocessed nuts, toasting completely prevented fungal contamination in shell pieces from nuts in the non-stored (NSN) group at the early maturity stage, while boiling significantly reduced the level of contamination to about 58% (p<0.05). In general, simulating open market conditions caused 100% fungal contamination in all boiled samples and toasted samples at early maturity. However, contamination in toasted samples at late maturity was increased to 90 and 70% at 25°C in DG18 and MEA, respectively, while at 37°C contamination was 40 and 60% in DG18 and MEA, respectively. Mycotoxin analysis using Yeast Extract Sucrose (YES) agar and High Performance Liquid Chromatography (HPLC)-Fluorescence detection (FLD) showed that Aflatoxins - G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates with both AFG1 and AFB1 being predominant at concentration ranges 4.33-32,200 and 4.20-22,700ng/g plug weight, respectively. No ochratoxin A (OTA) was detected out of 23 isolates analysed. From these findings, it is suggested that toasting of nuts, preferably at early maturity is a safer processing option than boiling in terms of prevention of possible fungal growth on nut shells and risk of mycotoxin contamination.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.

Effect of climate change on Aspergillus flavus and aflatoxin B1 production

This review considers the available information on the potential impact of key environmental factors and their interactions on the molecular ecology, growth and aflatoxin production by Aspergillus flavus in vitro and in maize grain. The recent studies which have been carried out to examine the impact of water activity × temperature on aflatoxin biosynthesis and phenotypic aflatoxin production are examined. These have shown that there is a direct relationship between the relative expression of key regulatory and structural genes under different environmental conditions which correlate directly with aflatoxin B1 production. A model has been developed to integrate the relative expression of 10 biosynthetic genes in the pathway, growth and aflatoxin B1 (AFB1) production which was validated under elevated temperature and water stress conditions. The effect of interacting conditions of aw × temperature × elevated CO2 (2 × and 3 × existing levels) are detailed for the first time. This suggests that while such interacting environmental conditions have little effect on growth they do have a significant impact on aflatoxin biosynthetic gene expression (structural aflD and regulatory aflR genes) and can significantly stimulate the production of AFB1. While the individual factors alone have an impact, it is the combined effect of these three abiotic factors which have an impact on mycotoxin production. This approach provides data which is necessary to help predict the real impacts of climate change on mycotoxigenic fungi.

Biodiversity and ITS-RFLP characterisation of Aspergillus section Nigri isolates in grapes from four traditional grape-producing areas in Greece

A study on the occurrence of Aspergillus section Nigri species on grapes from four traditional grape-producing areas in Greece during the 2011/2012 vintage, and their capability to produce OTA was conducted. One hundred and twenty-eight black aspergilli isolates were characterised at the species level initially by the use of morphological criteria in accordance with appropriate keys, followed by molecular characterisation performed with Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) of the 5.8 ribosomal RNA gene Internal Transcribed Spacer region (5.8 rRNA ITS). Restriction enzyme digestion of the ITS amplicons using the HhaI, HinfI and RsaI, endonucleases distinguished eleven different patterns of restriction fragment length polymorphism (RFLP), four for each of the HhaI and RsaI digests and three for HinfI. From a total number of 128 individual isolates, 124 were classified into four Aspergillus species corresponding to A. carbonarius, A. tubingensis, A. japonicus and A. ibericus, and the remaining 4 were classified as members of the A. niger aggregate. A. carbonarius and A. tubingensis being the main representative species were equally counted, with higher geographical representation of the former in southern and the latter in northern regions, respectively. All isolates were tested for their ochratoxigenic potential by use of High Performance Liquid Chromatography (HPLC) and Enzyme Linked Immuno Sorbent Assay (ELISA), resulting in significant interspecies differences in OTA production.

Outbreak of fungal endophthalmitis due to Fusarium oxysporum following cataract surgery

Outbreak of exogenous Fusarium endophthalmitis after cataract surgery was evaluated. Twenty patients developed postoperative endophthalmitis. In 19 eyes, pars plana vitrectomy (PPV) was performed, in 14 cases (74 %) with primary intraocular lens explantation. In one case, the PPV was not performed because of poor general condition of the patient. Symptoms of endophthalmitis (damaged vision, iritis, tyndallization in anterior chamber, hypopyon) occurred at intervals of 16-79 days (mean 31.3 days). Fungal etiology was documented in 12 eyes (60 %). Fusarium oxysporum was evidenced by culture and/or microscopy and confirmed by PCR and sequencing analysis. Eighteen (90 %) patients were treated with oral voriconazole (400 mg/day) for a period of 4-6 weeks. The final visual acuity was 6/15 in 1 case (5 %), 6/60 and worse in 17 eyes (85 %), and in 2 cases (10 %), enucleation had to be performed. Viscoelastic filling material was suggested the most likely source of infection. Endophthalmitis caused by Fusarium spp. are a potentially big threat for patients with serious impact on vision. Successful management of the infection is highly dependent on early diagnosis including species identification and antifungal susceptibility testing, and on aggressive and long-term treatment.

Kinetics of mould growth in the stored barley ecosystem contaminated with Aspergillus westerdijkiae, Penicillium viridicatum and Fusarium poae at 23-30 °C

BACKGROUND

Owing to the lack of a rapid method for determining fungi on cereals, the best way to enhance the safety and nutritive value of stored grain is to develop prognostic tools based on the relationship between easily measurable online parameters, e.g. water activity (a(w)) and temperature (t) of grain, and fungal growth. This study examined the effect of unfavourable temperature (23 and 30 °C) and humidity (0.80-0.94 a(w)) storage conditions on mould growth in the stored barley ecosystem with its adverse microbiological state provided by contamination with Aspergillus westerdijkiae, Penicillium viridicatum and Fusarium poae.

RESULTS

Among the applied storage parameters, a(w) turned out to be the main factor affecting mould development. The longest lag phase and period of fungal activation were observed for grain with 0.80 a(w), which was not threatened with fungal development for at least 30 days. However, in grain with 0.92 and 0.94 a(w), fungal activation occurred within 24-48 h.

CONCLUSION

The obtained data and the identification of critical points in mould growth may be used to develop a control system for the postharvest preservation of barley based on a(w) and temperature of grain, which are easy to measure in practice.

Contamination of barley seeds with Fusarium species and their toxins in Spain: an integrated approach

Fusarium is a globally distributed fungal genus that includes different species pathogenic to cereals among others crops. Some of these Fusarium species can also produce toxic compounds towards animals and humans. In this work, the presence of the most important Fusarium toxins was determined in barley seeds from Spain, sampled according to European Union requirements. The results obtained were compared with the presence of mycotoxigenic species considered responsible for their synthesis by using species-specific polymerase chain reaction protocols. Fumonisins B(1) and B(2), zearalenone, trichothecenes type A (T-2 and HT-2) and trichothecenes type B (deoxynivalenol and nivalenol) were analysed by using high-performance liquid chromatography. Deoxynivalenol and zearalenone were detected in 72% and 38% of the barley samples, respectively, at levels below European Union limits in all cases. However, the co-occurrence of both toxins in 34% of the samples suggested that synergistic activity of these two mycotoxins should be evaluated. Nivalenol and HT-2/T-2 were detected at low levels in 17% and 10% of the samples, respectively. Fumonisins occurred in 34% of the samples at levels up to 300 µg/kg. This suggested that they might represent a risk in Spanish barley, and to our knowledge, this is the first report on the presence of fumonisins in barley in this country. The species-specific polymerase chain reaction assays to detect mycotoxin-producing Fusarium species showed a very consistent correlation between F. verticillioides detection and fumonisin contamination as well as F. graminearum presence and zearalenone, deoxynivalenol and nivalenol contamination in barley samples. The approach used in this study provided information of mycotoxin contamination of barley together with the identification of the fungal species responsible for their production. Detection of the species with the current polymerase chain reaction assay strategy may be considered predictive of the potential mycotoxin risk in this matrix.

The presence of ochratoxin A in cord serum and in human milk and its correspondence with maternal dietary habits

BACKGROUND

Ochratoxin A (OTA) is a mycotoxin present in food that can be found in human blood and milk.

PURPOSE

The link between the nutritional habits of pregnant women both of Italian and foreign nationality resident in Italy and the presence of ochratoxin A in cord blood and in maternal milk was investigated.

METHODS

The study involved 130 pregnant women. Food consumption during pregnancy was evaluated by means of the EPIC questionnaire; OTA content was determined in cord serum and maternal milk by HPLC.

RESULTS

The mean daily dietary intake of OTA was 1.02 ± 1.20 and 0.87 ± 0.78 ng/kg of bodyweight for Italian and non-Italian women, respectively, but this difference was not statistically significant. The incidence of positive milk samples was 73.0 and 85.0% among the Italian and non-Italian mothers, respectively. Pork meat, soft drinks, sweets and red wine showed a significant relationship with OTA level in serum. As far as milk is concerned, a positive relationship resulted for pork meat, sweets, soft drinks and seed oils. A positive relationship between serum OTA level and the ratio serum/milk OTA was found. The intake of OTA had no effect on the cord blood creatinine level.

CONCLUSIONS

This study confirms that OTA is widely present in human milk and therefore could pose a risk for the newborn.

Mycotoxins in grapes and wine in Europe: occurrence, factors affecting the occurrence and related toxicological effects

In 2006, the European Commission has established maximum levels for ochratoxin A in wine and grape products, using occurrence data up to 2001 and toxicity data up to 2006. This paper presents an up-to-date overview of the occurrence of mycotoxins in grapes and wine produced in Europe in the period 1995-2010. In addition, for the most frequently occurring mycotoxins, factors influencing the occurrence, and the toxicological effects are presented. To evaluate possible trends in occurrence, contamination data were grouped into three periods of time, i.e. 1995-1999, 2000-2006 and 2007-2010. Most of the available contamination data on mycotoxins in grapes and wine refer to ochratoxin A, but occurrence data on this toxin from 2006 onwards are very limited. The occurrence of ochratoxin A is higher in the southern European countries than in the northern countries, and higher in red and sweet wines as compared to white wines. Fumonisins occur frequently, but in low concentrations. Data on the natural occurrence of Alternaria toxins are not available. The most important factors that influence ochratoxin A contamination of grapes and wine include: temperature and relative humidity in the month before harvesting the berries, the type of wine (maceration), and the percentage of damaged berries before vinification. Applying good agricultural practices in the vineyard, including minimizing damaged berries and chemical or biological control of the fungi, are the best methods to limit mycotoxin formation in grapes and wine. Ochratoxin A, Alternaria toxins and fumonisins are toxic to animals. These toxins are of concern to human health, but clear evidence on their relationship with human disease is not available yet. Therefore, more research in this area would be desirable.

Chemical, physical and biological approaches to prevent ochratoxin induced toxicoses in humans and animals

Ochratoxins are polyketide derived fungal secondary metabolites with nephrotoxic, immunosuppressive, teratogenic, and carcinogenic properties. Ochratoxin-producing fungi may contaminate agricultural products in the field (preharvest spoilage), during storage (postharvest spoilage), or during processing. Ochratoxin contamination of foods and feeds poses a serious health hazard to animals and humans. Several strategies have been investigated for lowering the ochratoxin content in agricultural products. These strategies can be classified into three main categories: prevention of ochratoxin contamination, decontamination or detoxification of foods contaminated with ochratoxins, and inhibition of the absorption of consumed ochratoxins in the gastrointestinal tract. This paper gives an overview of the strategies that are promising with regard to lowering the ochratoxin burden of animals and humans.

Perspectives for Geographically Oriented Management of Fusarium Mycotoxins in the Cereal Supply Chain

This article provides an overview of available systems for management of Fusarium mycotoxins in the cereal grain supply chain, with an emphasis on the use of predictive mathematical modeling. From the state of the art, it proposes future developments in modeling and management and their challenges. Mycotoxin contamination in cereal grain–based feed and food products is currently managed and controlled by good agricultural practices, good manufacturing practices, hazard analysis critical control points, and by checking and more recently by notification systems and predictive mathematical models. Most of the predictive models for Fusarium mycotoxins in cereal grains focus on deoxynivalenol in wheat and aim to help growers make decisions about the application of fungicides during cultivation. Future developments in managing Fusarium mycotoxins should include the linkage between predictive mathematical models and geographical information systems, resulting into region-specific predictions for mycotoxin occurrence. The envisioned geographically oriented decision support system may incorporate various underlying models for specific users' demands and regions and various related databases to feed the particular models with (geographically oriented) input data. Depending on the user requirements, the system selects the best fitting model and available input information. Future research areas include organizing data management in the cereal grain supply chain, developing predictive models for other stakeholders (taking into account the period up to harvest), other Fusarium mycotoxins, and cereal grain types, and understanding the underlying effects of the regional component in the models.

The type 2C protein phosphatase FgPtc1p of the plant fungal pathogen Fusarium graminearum is involved in lithium toxicity and virulence

Type 2C protein phosphatases (PP2Cs) are monomeric protein serine/threonine phosphatases that play various roles in eukaryotic organisms. In this study, we characterized the PP2C encoded by FgPTC1 in Fusarium graminearum, the major causal agent of Fusarium head blight on wheat and barley. We found that deletion of FgPTC1 delays the mycelium growth of F. graminearum in response to lithium. Consistently, FgPTC1 complemented the function of ScPTC1 in lithium toxicity in Saccharomyces cerevisiae. Furthermore, we showed that deletion of FgPTC1 attenuated the virulence of F. graminearum on wheat. Therefore, FgPTC1 plays an important role in regulating the hyphal growth and virulence of F. graminearum.

A conceptual model for identification of emerging risks, applied to mycotoxins in wheat-based supply chains

The research described in this paper focuses on identification of the most important indicators for emerging mycotoxins, starting from those produced by Fusarium fungi, in wheat-based feed and food supply chains, as well as the development of a conceptual model to predict the occurrence of these emerging toxins, based on the selected indicators. The selection of the most important indicators was based on a literature review and evaluation of the resulting indicators for their relevance. Each indicator selected was appointed to relevant stage(s) of the supply chain to which it is related and, for each indicator, a suggestion for a potential information source is given. The selected indicators cover various influential sectors, amongst others, weather conditions, agronomical practices, trade and legislation, as well as a variety of information sources, e.g. on-farm records and statistical organisations. The conceptual model developed is aimed at predicting the occurrence of emerging mycotoxins – based on the selected indicators – in a particular unit of wheat. The model takes a supply chain approach and can handle various types of indicators and various levels of detail of information on origin of the unit of wheat. The proposed model could be useful in the development of an identification system for emerging risks related to mycotoxins in wheat-based supply chains. Ultimately, such a system will help industry and policy makers in their decision-making process with regard to prevention and control of upcoming risks.

Mycotoxin assays using biosensor technology: a review

Toxic fungal metabolites - mycotoxins - cause poisonings after consumption of contaminated food commodities. The most probable intoxications are connected with eating poorly stored food or inhaling of moldy dust. One of the effective ways to protect people against mycotoxins is timely detection. Several methods such as affinity chromatography and enzyme-linked immunosorbent assay are commercially available for this purpose. Nevertheless, fast, sensitive, simple, portable, and low-cost devices are difficult to find. Application of biosensors appears to be a possible method to meet this need for mycotoxins assay.

Biological preservation of plant derived animal feed with antifungal microorganisms: safety and formulation aspects

During storage of moist animal feed, growth of detrimental fungi causing spoilage, or being mycotoxigenic or pathogenic, is a severe problem. Addition of biopreservative yeasts or lactic acid bacteria can significantly reduce this problem. However, their use requires several careful considerations. One is the safety to the animal, humans and the environment, tightly connected to legal aspects and the need for pre-market authorisation when supplementing feed with microorganisms. Although both yeasts and lactic acid bacteria are considered comparatively safe organisms due to low production of toxic metabolites, it is of great importance to understand the mechanisms behind the biopreservative abilities. Another important issue concerns practical aspects, such as the economic production of large amounts of the organisms and the development of a suitable formulation giving the organisms a long shelf life. These aspects are discussed and a recommendation of this review is that both safety and formulation aspects of a specific microbe should be considered at an early stage in the selection of new organisms with biopreservation potential.