Natural occurrence of ochratoxin A in dried figs

Total aflatoxin and ochratoxin A levels, dietary exposure and cancer risk assessment in dried fruits in Türkiye

This study aimed to measure total aflatoxin (AF) (AFB1, AFB2, AFG1, and AFG2) and ochratoxin A (OTA) levels in dried fruit samples and to evaluate the potential dietary exposure and cancer risk to these mycotoxins in Kayseri/Türkiye. Dried fruit samples were collected between April-May 2021. A total of 11 dried grapes and apricot samples, 7 dried fig and plum samples were collected. Total aflatoxins and OTA in dried fruits were determined by ELISA method. Then, the margin of exposure (MOE) and cancer risk were calculated. Total AF was detected in dried fruit samples between 42.86%, and 100%. Between 18.18% and 57.14% of samples exceeded the European Commission (EC) limits for total AF. Moreover, OTA was detected in all samples. Between 71.43% and 100% of samples exceeded the EC limits for OTA. Cancer risk due to OTA exposure was higher than total AF and it was determined that OTA exposure could pose a risk for public health (MOE < 10,000). Although mycotoxin exposure seems to be low due to the low consumption of dried fruit in Türkiye, the risk of exposure and cancer may increase because of complying with the recommendations of the dietary guidelines. The findings provide new insights into exposure to total AF and OTA through the consumption of dried fruit.

Aflatoxins and Ochratoxin A in dried fruits from Morocco: Monitoring, regulatory aspects, and exposure assessment

The present study aims to investigate the presence of Aflatoxins (AF) in 180 samples dried fruits and Ochratoxin A (OTA) in 210 samples dried fruits and grape juices collected in Morocco. Mycotoxins were analyzed by high performance liquid chromatography (HPLC) coupled to fluorescence detection and immunoaffinity columns (IAC) cleanup. Contamination levels were compared with the maximum regulatory limits (MRL) recently adopted in the country, and mycotoxin exposure of adult consumers was assessed. Results showed that 13.8% of samples were contaminated with AF, with incidences of 23.3, 23.3, 20, 13.8, and 3.3%, in raisins, figs, nuts, peanuts and pistachio, respectively. There were 12 samples (6.6%) that exceeded the MRL of 2-12 ng/g set for aflatoxin B1 (AFB1). While OTA was detected in 17.1% of samples, with incidences of 3.3, 3.3, 30, 30, and 53.3% in walnuts, pistachios, peanuts, raisins and figs, respectively, and a maximum value of 99.1 in dried raisins, that exceeded the MRL (10 ng/g) set for OTA. The co-occurrence of OTA and AF was observed in 4.7% of total samples. Dietary intake showed that the OTA exposure level was lower than safety guidelines set by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) at 100 ng/kg b.w./week.

Thermal Decontamination Technologies for Microorganisms and Mycotoxins in Low-Moisture Foods

The contamination risks of microorganisms and mycotoxins in low-moisture foods have heightened public concern. Developing novel decontamination technologies to improve the safety of low-moisture foods is of great interest in both economics and public health. This review summarizes the working principles and applications of novel thermal decontamination technologies such as superheated steam, infrared, microwave, and radio-frequency heating as well as extrusion cooking. These methods of decontamination can effectively reduce the microbial load on products andmoderately destruct the mycotoxins. Meanwhile, several integrated technologies have been developed that take advantage of synergistic effects to achieve the maximum destruction of contaminants and minimize the deterioration of products.

Effect of pretreatments on mycotoxin profiles and levels in dried figs

The aim of this explorative study was to investigate how effective drying preservation methods are in reducing mycotoxin content in figs. Dried autochthonous varieties of white and dark figs (Petrovača Bijela and Šaraguja, respectively) were analysed for mycotoxins using an LC-MS/MS "dilute and shoot" method capable of determining 295 fungal and bacterial secondary metabolites. Before drying in a cabinet dryer the figs were preserved with 0.5 % citric acid solution or 0.5 % ascorbic acid solution or 0.3 % L-cysteine solution or 0.2 % chestnut extract solution or 0.15 % Echinacea extract solution by immersion. We found nine metabolites: aflatoxin B1 (AFB1), ochratoxin A, ochratoxin alpha, kojic acid, emodin, altenuene, alternariol methyl ether, brevianamide F, and tryptophol. The most efficient preserver was L-cysteine (15 % reduction), while ascorbic acid favoured mycotoxin production (158 % increase). However, all pretreatment solutions reduced AFB1, which is a major fig contaminant.

Isolation and Evaluation of New Antagonist Bacillus Strains for the Control of Pathogenic and Mycotoxigenic Fungi of Fig Orchards

Bacillus is an antagonistic bacteria that shows high effectiveness against different phytopathogenic fungi and produces various lytic enzymes, such as chitosanase, chitinase, protease, and gluconase. The aim of this study is to determine Bacillus spp. for lytic enzyme production and to evaluate the antifungal effects of the selected strains for biocontrol of mycotoxigenic and phytopathogenic fungi. A total of 92 endospore-forming bacterial isolates from the 24 fig orchard soil samples were screened for chitosanase production, and six best chitosanolytic isolates were selected to determine chitinase, protease, and N-acetyl-β-hexosaminidase activity and molecularly identified. The antagonistic activities of six Bacillus strains against Aspergillus niger EGE-K-213, Aspergillus foetidus EGE-K-211, Aspergillus ochraceus EGE-K-217, and Fusarium solani KCTC 6328 were evaluated. Fungal spore germination inhibition and biomass inhibition activities were also measured against A. niger EGE-K-213. The results demonstrated that Bacillus mojavensis EGE-B-5.2i and Bacillus thuringiensis EGE-B-14.1i were more efficient antifungal agents against A. niger EGE-K-213. B. mojavensis EGE-B-5.2i has shown maximum inhibition of the biomass (30.4%), and B. thuringiensis EGE-B-14.1i has shown maximum inhibition of spore germination (33.1%) at 12 h. This is the first study reporting the potential of antagonist Bacillus strains as biocontrol agents against mycotoxigenic fungi of fig orchads.

Determination of mycotoxins in biscuits, dried fruits and fruit jams: an assessment of human exposure

A reliable, fast and simple method using UHPLC-MS/MS was developed for the determination of aflatoxins B₁ (AFB1), G₁ (AFG1), B₂ (AFB2) and G₂ (AFG2), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), HT-2 toxin and T-2 toxin in crude extracts of biscuits with fruit filling, cookies, dried fruits and fruit jams. The method was successfully demonstrated on 39 samples of biscuits with fruit filling, 34 cookies, 14 dried fruits and 10 fruit jams. The mycotoxins detected in biscuits samples were ZEA, OTA, T-2 and AFB1 with an average concentrations of positive samples of 2.64, 4.10, 8.13 and 1.32 µg kg^-1, respectively; while the mycotoxins detected in jam samples were AFB1, OTA, T-2 and AFB2 with an average concentrations of positive samples of 2.00, 17.7, 4.37 and 1.15 µg kg^-1, respectively. The results showed that the majority of samples were in compliance with relevant regulations. However in eight samples of biscuits and three samples of fig jam the contents of OTA were higher than the existing OTA limits. The combined dietary exposure of selected mycotoxins was estimated for the first time for children, adolescents and adults. The estimated combined dietary exposures were all lower than the proposed value assumed to predict a possible risk scenario.

Detection of aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared reflectance spectroscopy

BACKGROUND

Aflatoxins are toxic metabolites that are mainly produced by members of the Aspergillus section Flavi on many agricultural products. Certain agricultural products such as figs are known to be high risk products for aflatoxin contamination. Aflatoxin contaminated figs may show a bright greenish yellow fluorescence (BGYF) under ultraviolet (UV) light at a wavelength of 365 nm. Traditionally, BGYF positive figs are manually selected by workers. However, manual selection depends on the expertise level of the workers and it may cause them skin-related health problems due to UV radiation.

RESULTS

In this study, we propose a non-invasive approach to detect aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared (FT-NIR) reflectance spectroscopy. A classification accuracy of 100% is achieved for classifying the figs into aflatoxin contaminated/uncontaminated and surface mould contaminated/uncontaminated categories. In addition, a strong correlation has been found between aflatoxin and surface mould.

CONCLUSION

Combined with pattern classification methods, the NIR spectroscopy can be used to detect aflatoxin contaminated figs non-invasively. Furthermore, a positive correlation between surface mould and aflatoxin contamination leads to a promising alternative indicator for the detection of aflatoxin-contaminated figs. © 2016 Society of Chemical Industry.

Amino acid functionalized ZrO2 nanoparticles decorated reduced graphene oxide based immunosensor

Here, a study is reported on a simple, one-step method for the synthesis of a zirconium dioxide–reduced graphene oxide (ZrO₂–RGO) nanocomposite and its functionalization with amino acid to develop an immunosensor for detection of ochratoxin A.

Influence of Butylated Hydroxyanisole on the Growth, Hyphal Morphology, and the Biosynthesis of Fumonisins in Fusarium proliferatum

Fusarium proliferatum as a common fungus pathogen in foods can produce toxic fumonisins, which can cause animal diseases and increase risks of human cancers. On contrary, butylated hydroxyanisole (BHA) as a synthetic antioxidant offers a clue for preventing growth of fungal species and inhibiting production of mycotoxins. Unfortunately, information of the inhibitory mechanism of BHA on Fusarium species is still limited. In this study, influence of BHA treatment on growth and inhibition of fumonisin production in relation to the expression of the fumonisin biosynthesis-related genes of the F. proliferatum ZYF was investigated, which revealed that BHA had a negative influence on growth and fumonisin production of F. proliferatum. To further elucidate the mechanism of BHA on the growth of F. proliferatum, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the F. proliferatum hyphae. The BHA treatment induced the loss of cytoplasm and cellular constituents, as well as distortion of mycelia, but it did not directly degrade the fumonisin. Furthermore, the BHA treatment markedly inhibited the expressions of FUM1 (a polyketide synthase encoding gene) and FUM8 (an aminotransferase encoding gene) genes, which resulted in the depression of metabolic pathway of F. proliferatum. The transcriptional analyses of the FUM1 and FUM8 genes confirmed a correlation between the fumonisin production and its gene expression. This study provided some insights into mechanisms of production of fumonisin and feasible prevention to reduce fumonisin contamination in favor of human and animal health.

Nation-Based Occurrence and Endogenous Biological Reduction of Mycotoxins in Medicinal Herbs and Spices

Medicinal herbs have been increasingly used for therapeutic purposes against a diverse range of human diseases worldwide. Moreover, the health benefits of spices have been extensively recognized in recent studies. However, inevitable contaminants, including mycotoxins, in medicinal herbs and spices can cause serious problems for humans in spite of their health benefits. Along with the different nation-based occurrences of mycotoxins, the ultimate exposure and toxicities can be diversely influenced by the endogenous food components in different commodities of the medicinal herbs and spices. The phytochemicals in these food stuffs can influence mold growth, mycotoxin production and biological action of the mycotoxins in exposed crops, as well as in animal and human bodies. The present review focuses on the occurrence of mycotoxins in medicinal herbs and spices and the biological interaction between mold, mycotoxin and herbal components. These networks will provide insights into the methods of mycotoxin reduction and toxicological risk assessment of mycotoxin-contaminated medicinal food components in the environment and biological organisms.

Ochratoxin A in dried grapes in Hamadan province, Iran

The occurrence of ochratoxin A (OTA) in dried grapes was surveyed in this study. Sixty-six samples of dried grapes (40 currants, 16 sultanas and 10 raisins) were collected from dried grapes factories in Hamadan province, Iran, from October 2012 to March 2013. High-performance liquid chromatography (HPLC) was used to determine OTA in these samples. OTA was detected in 23 (57.5%) currants, 10 (62.5%) sultanas and 6 (60%) raisins samples. Levels in five samples exceeded the Institute of Standards and Industrial Research of Iran (ISIRI) maximum level of 5 µg/kg. However, OTA content in none of the samples exceeded the maximum limit prescribed in the European Union (EU) regulations, which is 10 µg/kg. The obtained data contribute to information on OTA levels in Iranian dried grapes.

Natural occurrence, analysis, and prevention of mycotoxins in fruits and their processed products

Mycotoxins are small toxic chemical products formed as the secondary metabolites by fungi that readily contaminate foods with toxins in the field or after harvest. The presence of mycotoxins, such as aflatoxins, ochratoxin A, and patulin, in fruits and their processed products is of high concern for human health due to their properties to induce severe acute and chronic toxicity at low-dose levels. Currently, a broad range of detection techniques used for practical analysis and detection of a wide spectrum of mycotoxins are available. Many analytical methods have been developed for the determination of each group of these mycotoxins in different food matrices, but new methods are still required to achieve higher sensitivity and address other challenges that are posed by these mycotoxins. Effective technologies are needed to reduce or even eliminate the presence of the mycotoxins in fruits and their processed products. Preventive measures aimed at the inhibition of mycotoxin formation in fruits and their processed products are the most effective approach. Detoxification of mycotoxins by different physical, chemical, and biological methods are less effective and sometimes restricted because of concerns of safety, possible losses in nutritional quality of the treated commodities and cost implications. This article reviewed the available information on the major mycotoxins found in foods and feeds, with an emphasis of fruits and their processed products, and the analytical methods used for their determination. Based on the current knowledge, the major strategies to prevent or even eliminate the presence of the mycotoxins in fruits and their processed products were proposed.

Natural occurrence of mycotoxins in medicinal plants: a review

Medicinal plants are widely used as home remedies and raw materials for the pharmaceutical industries. Herbal remedies are used in the prevention, treatment and cure of disorders and diseases since ancient times. However, use of medicinal herbs may not meet the requirements of quality, safety and efficacy. During harvesting, handling, storage and distribution, medicinal plants are subjected to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity and quality of these natural products. The increase in use of medicinal plants may lead to an increase in the intake of mycotoxins therefore contamination of medicinal plants with mycotoxins can contribute to adverse human health problems and therefore represents a special hazard. Numerous natural occurrences of mycotoxins in medicinal plants and traditional herbal medicines have been reported from various countries including Spain, China, Germany, India, Turkey and from Middle East as well. This review discusses the important mycotoxins and their natural occurrences in medicinal plants and their products.

Preliminary survey of aflatoxins and ochratoxin a in dried fruits from Iran

Forty five dried fruits, 30 dried apricots and 15 prunes were tested for aflatoxins and ochratoxin A contamination utilizing immunoaffinity column clean up and high performance liquid chromatography (HPLC) with fluorescence detection. 30% and 3.33% of examined apricot samples and 13.33% and 20% of examined prunes samples contained aflatoxin B(1) and ochratoxin A more than 0.2 ng g(-1). The average recoveries were found to be 91.1% and 98.5% for aflatoxin B(1) and ochratoxin A, respectively, while the detection limit was 0.2 ng g(-1) for both mycotoxins.

The use of high-performance liquid chromatography to detect ochratoxin A in dried figs from the Spanish market

BACKGROUND

Detection and quantification of ochratoxin A (OTA) in dried fig samples purchased in Spain has been carried out using high-performance liquid chromatography with fluorescence detection after extraction with methanol and sodium bicarbonate, and clean-up by using an immunoaffinity column.

RESULTS

The detection limit of the method was 0.06 ng g(-1), and the limit of quantification 0.18 ng g(-1) . OTA was detected in 31 (88.6%) out of 35 samples of dried figs analysed, with concentrations that ranged from < 0.1 to 277 ng g(-1). However, only three samples contained OTA concentrations above the tolerable level set by European Commission regulations for dried vine fruits (10 ng g(-1)).

CONCLUSION

The results of this survey show the value of monitoring OTA in dried figs especially if they are home grown.

Mycotoxin food and feed regulation and the specific case of ochratoxin A: a review of the worldwide status

Mycotoxins are naturally occurring contaminants whose presence in food- and feedstuffs cannot be completely avoided. The safety and economic impact arising from the commercialization of mycotoxin-contaminated food and feed supply chain is considerable and acknowledged. To protect consumers from mycotoxin-derived health risks, many countries have adopted regulations or guidelines to limit exposure. Similar to regulation for other mycotoxins, the regulatory status of ochratoxin A (OTA) lacks consensus. Although this was one of the first fungal toxins to be subjected to compliance control due to its toxic properties, the conflict between the prime objective of consumer health safeguard and the economic interests of producers and traders remains. One of the key challenges facing policymakers is to balance these conflicting demands and reach consensual regulatory actions or limits. The noteworthy transboundary implications are recognized, both in the case of absence as the unsubstantiated tightening of regulatory limits. This paper scrutinizes the rationales and implications of mycotoxin regulation, with special attention devoted to OTA. In view of the ongoing debate concerning this complex issue, a review of the arguments and suggested strategies proposed by different parties is also made. The specific case of OTA regulation in food and feed is updated and analysed at a European Union and global level.

Ecophysiology of Aspergillus section nigri species potential ochratoxin a producers

After aflatoxins, ochratoxin A (OTA) is the most studied mycotoxin due to the toxicological significance in human and animal diets. OTA presence has been extensively reported worldwide in the last decade in several agricultural products. The main OTA producer in tropical and temperate climates is Aspergillus carbonarius followed by species belonging to A. niger aggregate. Currently, many scientists worldwide have studied the influence of water activity and temperature for growth and biosynthesis of OTA by these species on synthetic media. This article reviews ecophysiological studies of Aspergillus section Nigri strains on synthetic media and natural substrates. The results of these investigations suggest that significant amounts of OTA can be produced in only five days and that the use of different storage practices, such as a(W) and temperature levels below 0.930 and 15 °C, respectively, allow controlling fungal contamination and minimizing the OTA production in several products as peanuts, corn, dried grapes and derived products for human consumption.

Incidence of ochratoxin A in dried fruits and co-occurrence with aflatoxins in dried figs

Ninety eight dried figs, 53 sultanas and 20 dried apricots destined for export from Turkey to the European Union were tested for ochratoxin A (OTA) contamination utilizing immunoaffinity column clean-up and high-performance liquid chromatography (HPLC). While only 2 (4%) of the sultanas exceeded the 10 ng g(-1) maximum limit set by the EU, 28 (53%) of 53 sultana samples contained detectable levels of OTA, in the range of 0.51-58.04 ng g(-1). Eighteen of 98 (18%) dried figs contained detectable levels of OTA, in the range of 0.87-24.37 ng g(-1). Only one of the 20 dried apricots was contaminated, with 0.97 ng g(-1) OTA. Dried figs analyzed for OTA were also tested for aflatoxin contamination to determine the co-occurrence of both toxins. Seven samples were confirmed aflatoxin positive, in the range of 0.23-4.28 ng g(-1), and only 2 samples contained both toxins, with a maximum concentration of 24.37 ng g(-1)for OTA and 1.02 ng g(-1) for aflatoxin B(1). The average recovery and relative standard deviation (RSD) obtained from dried fruits spiked with OTA ranged from 80.5% to 91.5% and 0.99-5%, respectively. The average recovery and relative standard deviation (RSD) obtained from dried figs spiked with aflatoxin ranged from 88.78% to 93.53% and 2.54-7.25%, respectively.

Comparison of enzyme linked immunoassay and high performance liquid chromatography for determination of fumonisin in dried figs

The occurrence of fumonisin in dried figs was investigated by Enzyme Linked Immunoassay (ELISA) and High Performance Liquid Chromatography (HPLC). Total fumonisins (FB1, FB2, FB3) in dried figs were determined using ELISA, whereas only fumonisin B1 (FB1) was determined by HPLC. In the period 2003-2004, one hundred and fifty five dried fig samples were taken during their drying in 7 different districts in the Aegean Region. Among a total of 115 samples, the incidence of total fumonisin in the dried figs was 82% within the range of 0.16 - 108.34 mg/g when determined by ELISA. In comparison, FB1 was detected in 86 samples (74.8%) within the range between 0.046 and 3.649 mg/g by HPLC. Correlation between ELISA and HPLC methods was observed for all samples. However, no correlation between methods was recorded for the samples with less than 1 mg/g Fumonisin B1 level (obtained by HPLC). Although there was a correlation between methods for all the samples, fumonisin levels obtained by ELISA were much higher than those obtained by HPLC. False positive results were obtained by ELISA in 11 out of 115 dried fig samples. The results indicated that ELISA can be used as a screening method for determining the occurence of fumonisin in dried figs.

Analytical methods for determination of mycotoxins: a review

Mycotoxins are small (MW approximately 700), toxic chemical products formed as secondary metabolites by a few fungal species that readily colonise crops and contaminate them with toxins in the field or after harvest. Ochratoxins and Aflatoxins are mycotoxins of major significance and hence there has been significant research on broad range of analytical and detection techniques that could be useful and practical. Due to the variety of structures of these toxins, it is impossible to use one standard technique for analysis and/or detection. Practical requirements for high-sensitivity analysis and the need for a specialist laboratory setting create challenges for routine analysis. Several existing analytical techniques, which offer flexible and broad-based methods of analysis and in some cases detection, have been discussed in this manuscript. There are a number of methods used, of which many are lab-based, but to our knowledge there seems to be no single technique that stands out above the rest, although analytical liquid chromatography, commonly linked with mass spectroscopy is likely to be popular. This review manuscript discusses (a) sample pre-treatment methods such as liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE), (b) separation methods such as (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC), and capillary electrophoresis (CE) and (c) others such as ELISA. Further currents trends, advantages and disadvantages and future prospects of these methods have been discussed.