Ochratoxin A levels in spices and dried nuts consumed in Tunisia

Mycotoxin contamination in the Arab world: Highlighting the main knowledge gaps and the current legislation

Since the discovery of aflatoxins in the 1960s, knowledge in the mycotoxin research field has increased dramatically. Hundreds of review articles have been published summarizing many different aspects, including mycotoxin contamination per country or region. However, mycotoxin contamination in the Arab world, which includes 22 countries in Africa and Asia, has not yet been specifically reviewed. To this end, the contamination of mycotoxins in the Arab world was reviewed not only to profile the pervasiveness of the problem in this region but also to identify the main knowledge gaps imperiling the safety of food and feed in the future. To the best of our knowledge, 306 (non-)indexed publications in English, Arabic, or French were published from 1977 to 2021, focusing on the natural occurrence of mycotoxins in matrices of 14 different categories. Characteristic factors (e.g., detected mycotoxins, concentrations, and detection methods) were extracted, processed, and visualized. The main results are summarized as follows: (i) research on mycotoxin contamination has increased over the years. However, the accumulated data on their occurrences are scarce to non-existent in some countries; (ii) the state-of-the-art technologies on mycotoxin detection are not broadly implemented neither are contemporary multi-mycotoxin detection strategies, thus showing a need for capacity-building initiatives; and (iii) mycotoxin profiles differ among food and feed categories, as well as between human biofluids. Furthermore, the present work highlights contemporary legislation in the Arab countries and provides future perspectives to mitigate mycotoxins, enhance food and feed safety, and protect the consumer public. Concluding, research initiatives to boost mycotoxin research among Arab countries are strongly recommended.

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.

Quantification of Ochratoxin A in 90 spice and herb samples using the ELISA method

This study addressed the challenge of accurately detecting mycotoxins in herbs and spices, which have gained popularity as alternative medicines but pose health risks due to potential contamination. We used a competitive direct ELISA kit (Art No. 8610), Veratox for Ochratoxin, to quantify Ochratoxin A in the herb and spice samples. The samples were first prepared using solid-liquid extraction with 70% methanol. The resulting filtrate was then subjected to ELISA analysis. The results of the analysis were then further analyzed using principal component analysis (PCA). In this study, PCA was used to classify the concentration levels of Ochratoxin A based on various factors, such as the packaging type, country of origin, shelf life, and sample weight. The limits of detection (LOD) and quantification (LOQ) values indicate the lowest amount of Ochratoxin A that can be detected and quantified, respectively, with high accuracy and precision. The range of the LOD and LOQ values (0.43-0.58 µg/kg and 1.45-1.95 µg/kg, respectively) suggests that the method used was capable of detecting and quantifying Ochratoxin A in the herb and spice samples at different concentrations with a high degree of accuracy and precision. These results suggest that while most of the samples (73.33%) were below the maximum residue limit (MRL) for Ochratoxin A, a significant number of samples (26.67%) had concentrations of Ochratoxin A that were higher than the MRL. This highlights the importance of monitoring Ochratoxin A in herb and spice samples and ensuring the products are safe for consumption.

Modified-QuEChERS-LC/MS method for the analysis of aflatoxins and ochratoxin A in coriander seeds

Coriander seeds consumption, like other spices, has increased due to its culinary use, medicinal benefits, and its essential oil. However, there are few reports in the scientific literature on the prevalence of mycotoxins in this spice. In this report, an easy and simple method was proposed for the determination of the aflatoxin group (AFB1, AFB2, AFG1, and AFG2) and ochratoxin A (OTA) in coriander seeds. The recoveries of analytes ranged from 72 to 102% in spiked samples (0.5-5 µg/kg), with RSD below 11%. The limits of quantification (LOQ) are between 0.12 and 0.5 µg/kg. The proposed method represents an improvement compared to previous studies. It was tested for the determination of 13 samples, proving that it is fast, efficient, and sensitive. Only OTA was identified in four samples, all at levels lower than the European limits defined for some spices (0.88 and 5.4 µg/kg). Such methods are needed for monitoring these toxins in this spice to ensure consumer safety and provide insight into their occurrence.

Public health risk associated with the co-occurrence of aflatoxin B1 and ochratoxin A in spices, herbs, and nuts in Lebanon

Background

Aflatoxin B1 and ochratoxin A are mycotoxins produced by filamentous fungi that attack crops on field and storage. Both mycotoxins present a risk on public health since aflatoxin B1 is a hepatotoxic and hepatocarcinogenic agent while ochratoxin A can be nephrotoxic. Those mycotoxins can be found in several food items including spices, herbs, and nuts.

Objectives

In Lebanon, few studies address aflatoxin B1 and ochratoxin A contamination in spices, herbs, and nuts. So, the aim of this study is to investigate the concentrations of those two mycotoxins particularly in spices and herbs and the concentration of aflatoxin B1 in nuts, and to determine the dietary exposure of the Lebanese population and their possible attribution to liver cancer and renal damage.

Methods

In this work, a total of 198 samples of spices, herbs, and nuts were collected from different sites. Aflatoxin B1 and ochratoxin A were quantified using immune-affinity columns. A food frequency questionnaire was used to quantify the consumption of spices, herbs, and nuts in Lebanon. Exposure to aflatoxin B1 and ochratoxin A was calculated accordingly and liver and kidney cancer risks were evaluated.

Results

Aflatoxin B1 was respectively found in 100, 20.4, and 98.6% of the spices, herbs, and nuts samples, while ochratoxin A was found in 100 and 44.4% of spices and herbs, respectively. Aflatoxin B1 was found at mean concentration of 0.97, 0.27, and 0.40 μg/kg in spices, herbs, and nuts, respectively while ochratoxin A was found at mean concentrations of 38.8 and 1.81 μg/kg in spices and herbs, respectively. Aflatoxin B1 occurrence was shown to be associated in this study with 0.017 additional cancer cases per 100,000 persons per year, and ochratoxin A weekly exposure was shown to be 5.04 ng/kg bw less than the Provisional Tolerable Weekly Intake of 100 ng/kg bw which indicates low risk of renal damage from spices and herbs consumption.

Conclusion

The consumption of spices, herbs, and nuts in Lebanon could lead to an increase in health risks associated with aflatoxin B1 and ochratoxin A, specifically spices. The reported occurrence may be directly related to poor storage conditions.

Deep Genotypic Species Delimitation of Aspergillus Section Flavi Isolated from Brazilian Foodstuffs and the Description of Aspergillus annui sp. nov. and Aspergillus saccharicola sp. nov

Aspergillus section Flavi is a fungal group that is important in food because it contains spoilage and potentially aflatoxigenic species. Aflatoxins are metabolites that are harmful to human and animal health and have been recognized as the primary natural contaminant in food. Therefore, recognizing the biodiversity of this group in food is necessary to reduce risks to public health. Our study aimed to investigate the diversity of Aspergillus section Flavi isolated from Brazilian foodstuffs such as cassava, sugarcane, black pepper, paprika, Brazil nuts, yerba-mate, peanuts, rice, and corn. A polyphasic approach integrating phenotypic data and multilocus genotypic analyses (CaM, BenA, and RPB2) was performed for 396 strains. Two new species in the Aspergillus subgenus Circumdati section Flavi are proposed using maximum-likelihood analysis, Bayesian inference, and coalescence-based methods: Aspergillus saccharicola sp. nov. and Aspergillus annui sp. nov. A. saccharicola sp. nov. belongs to the series Flavi, is a potentially aflatoxigenic species (B1, B2, G1, and G2), closely related to Aspergillus arachidicola, and was found mostly in sugarcane. A. annui sp. nov. was isolated from samples of sweet paprika. To accommodate A. annui sp. nov., a new series Annuorum was proposed.

Revalorization of Almond By-Products for the Design of Novel Functional Foods: An Updated Review

The search for waste minimization and the valorization of by-products are key to good management and improved sustainability in the food industry. The great production of almonds, based on their high nutritional value as food, especially almond kernels, generates tons of waste yearly. The remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. The interest in these by-products has been increasing, as they possess beneficial properties, caused by the presence of different bioactive compounds, and can be used as promising sources of new ingredients for the food, cosmetic and pharmaceutical industry. Additionally, the use of almond by-products is being increasingly applied for the fortification of already-existing food products, but there are some limitations, including the presence of allergens and mycotoxins that harden their applicability. This review focuses on the extraction technologies applied to the valorization of almond by-products for the development of new value-added products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry.

Predictive Modeling and Validation on Growth, Production of Asexual Spores and Ochratoxin A of Aspergillus Ochraceus Group under Abiotic Climatic Variables

This study aimed to generate predictive models for growth, sporulation, and ochratoxin A (OTA) production under abiotic climatic variables, including temperatures (15-35 °C) and water activity levels (0.99-0.90 aw) by Aspergillus ochraceus group. The data were divided into three sets: one for training, one for testing, and the third one for model validation. Optimum growth occurred at 0.95 aw and 25 °C and 0.95 aw and 30 °C for A. westerdijkiae and A. steynii, respectively. Significantly improved A. westerdijkiae and A. steynii spore production occurred at 0.95 aw and 20 °C and 0.90 aw and 35 °C, respectively. A. steynii and A. westerdijkiae produced the majority of OTA at 35 °C and 0.95 aw and 25-30 °C at 0.95-0.99 aw, respectively. The accuracy of the third-order polynomial regression model reached 96% in growth cases, 94.7% in sporulation cases, and 90.9% in OTA production cases; the regression coefficients (R2) ranged from 0.8819 to 0.9978 for the Aspergillus ochraceus group. A reliable agreement was reached between the predicted and observed growth, sporulation, and OTA production. The effects of abiotic climatic variables on growth, sporulation, and OTA production of A. ochraceus group have been effectively defined, and the models generated were responsible for adequately predicted and validated models against data from other strains within A. ochraceus group that had been published in the literature under the current treatments. These models could be successfully implemented to predict fungal growth and OTA contamination on food matrices for these strains under these conditions.

A facile extraction method followed by UPLC-MS/MS for the analysis of aflatoxins and ochratoxin A in raw coffee beans

A UPLC-MS/MS method was developed and validated for the determination of aflatoxin B₁ (AFB1), aflatoxin B₂ (AFB2), aflatoxin G₁ (AFG1), aflatoxin G₂ (AFG2) and ochratoxin A (OTA) in raw coffee samples. Mycotoxins were extracted using a modified QuEChERS method with little sample preparation excluding clean-up and enrichment procedures. Linearity was demonstrated for the five mycotoxins in the range 0.125-20 µg/kg. This method shows negligible matrix effect for individual concentrations, thus allowing the use of an external standard procedure. Limits of quantification (LOQ) ranged from 0.45 to 1 μg/kg. Recoveries between 63% and 89% were achieved. The intra- and inter-day precisions were lower than 15%. The applicability of the method was demonstrated, taking into account fitness for purpose, with simplicity, reliability, low costs and environmental friendliness. The results show that 3 out of 4 samples were contaminated with OTA.

Detection of Aflatoxin and Ochratoxin A in Spices by High-Performance Liquid Chromatography

Background. Spices are one of the flavoring components of food in the cooking recipes of different nations that are used daily. However, these ingredients may be contaminated by toxicogenic fungi and subsequent production of mycotoxins that cannot be neutralized through cooking. In the present study, the possible contamination of spices by aflatoxins (AFs) and ochratoxin A (OTA) was investigated from Shiraz, the south part of Iran. Materials and Methods. A total of 80 spice samples including turmeric (n = 20), red pepper (n = 20), black pepper (n = 20), and cinnamon (n = 20) were purchased from markets and cultured on appropriate medium. The isolated fungi were identified. Simultaneously, mycotoxins from spices were extracted with immunoaffinity columns (IAC) and the occurrence of AFs (B1 + B2 + G1 + G2) and OTA was then determined using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). Result. The results depicted that 40 spice samples were contaminated with AFs and 48 samples with OTA. The highest rate of AFs contamination was related to red pepper, in 80% of which the amount of contamination was excessive than the standard level (>10 μg/kg). All black pepper samples were determined to be contaminated with OTA at over legislation limits of >15 μg/kg. Aspergillus species were the predominant isolated fungi, followed by Penicillium, and Mucor species. Discussion. Regarding the high mycotoxins contamination in spices in the current study, regular effective surveillance and quality control procedures are highly recommended. To achieve this goal, it is necessary to empower food-related laboratories with precise methods of isolation and detection of mycotoxins.

Heat Stability of Ochratoxin A in an Aqueous Buffered Model System

Ochratoxin A (OTA) represents one of the most widespread mycotoxins in agricultural commodities in the world and is considered a possible human carcinogen with its potent nephrotoxicity. OTA is stable under most food processing conditions; however, higher-temperature treatment may reduce OTA content in foods. Since OTA can be found in processed products destined for both human and animal consumption, factors affecting its stability or reduction during thermal processes were investigated here. The reduction of OTA was measured during various heating times (up to 60 min) at different temperatures (100, 125, 150, 175, and 200°C) in aqueous buffer solutions at different pHs (pH 4, 7, and 10). Quantification of OTA was carried out using high-performance liquid chromatography with fluorescence detection. The results showed that the rate and extent of OTA reduction were dependent on pH, processing time, and temperature; greater than 90% OTA reduction was achieved at 200°C for all treatments except pH 4. After processing under an alkaline condition (pH 10) at 100°C for 60 min, about 50% of the OTA was lost, while after 60 min under neutral and acidic conditions at 100°C, significant reductions of OTA were not shown.

Effects of different drying treatments on fungal population and ochratoxin A occurrence in sultana type grapes

This study aimed to determine the changes in mould and ochratoxin A (OTA) occurrence in sultanas under three different conventional drying conditions. Five different vineyards were chosen, and the three different treatments were applied to these grapes while drying. At the end of the drying process, total mould and black aspergilli (BA) populations in the samples varied from 2.45 to 5.61 log colony-forming units (CFU) g(-)(1) and from 0 to 4.92 log CFU g(-)(1), respectively. Significant increases (p < 0.05) occurred in mould loads depending on the extending drying period. However, independent of vineyard location, all the samples treated with cold dipping solution showed the lowest fungal loads. These results indicate that dipping solution treatment was the most effective drying method to minimise fungal infection of grapes. The expected results could not be achieved by drying grapes artificially contaminated with ochratoxigenic Aspergillus carbonarius spores. Seventy-one of 96 isolates (73.95%) obtained during drying were Aspergillus spp., and the remaining (n = 25, 26.05%) belonged to other genera, such as Penicillium, Trichoderma and Cladosporium. Grape juice-based agar medium was used to determine the realistic OTA production capacities of the isolated mould strains. The highest OTA production capacities were 809.70 ± 9.19, 87.58 ± 16.89 and 45.44 ± 18.78 ng g(-1) in 50% grape juice agar (GJ50), all five of which were from A. niger isolates. OTA was not present in any sample during the drying period; however, OTA was detected in two samples at 0.32 ± 0.15 and 0.52 ± 0.36 µg kg(-)(1) after the end of the drying process. The limit of detection (LOD) and limit of quantitation (LOQ) of the method used for detecting OTA in samples were 0.1 and 0.3 µg kg(-)(1), respectively.

Ochratoxin A Contamination of Red Chili Peppers from Chile, Bolivia and Peru, Countries with a High Incidence of Gallbladder Cancer

Our previous study detected aflatoxins in red chili peppers from Chile, Bolivia, and Peru, each of which have a high incidence of gallbladder cancer (GBC). Since the aflatoxin B1 concentration was not so high in these peppers, it is important to clarify the presence of other mycotoxins. Here we attempted to determine any associations between the concentrations of aflatoxins and ochratoxin A (OTA) in red chili peppers, and the corresponding GBC incidences. We collected red chili peppers from three areas in Peru: Trujillo (a high GBC incidence area), Cusco (an intermediate GBC incidence area), and Lima (a low GBC incidence rate), and from Chile and Bolivia. Aflatoxins and OTA were extracted with organic solvents. The concentrations of aflatoxins B1, B2, G1, and G2, and OTA were measured by high-performance liquid chromatography. The values obtained were compared with the incidence of GBC in each area or country. All of the red chili peppers from the three areas showed contamination with aflatoxins below the Commission of the European Communities (EC) recommended limits (5 μg/kg), but the OTA contamination of two samples was above the EC recommended limit (15 μg/kg). The mean concentrations of OTA in the peppers from Chile (mean 355 μg/kg, range <5-1,059 μg/kg) and Bolivia (mean 207 μg/kg, range 0.8-628 μg/kg), which has a high incidence of GBC, were higher than that in Peru (14 μg/kg, range <5-47 μg/kg), which has an intermediate GBC incidence. The OTA contamination in the red chili peppers from Chile, Bolivia, and Peru was stronger than that of aflatoxins. Our data suggest that OTA in red chili peppers may be associated with the development of GBC.

Blood, breast milk and urine: potential biomarkers of exposure and estimated daily intake of ochratoxin A: a review

The purposes of this review are to study potential biomarkers of exposure for ochratoxin A (OTA) in biological fluids (blood, urine and breast milk) for the period 2005-14, calculate the estimated daily intake (EDI) of OTA by using database consumption for the Spanish population, and, finally, to correlate OTA levels detected in blood and EDI values calculated from food products. The values of OTA detected in potential biomarkers of exposure for blood, breast milk and urine ranged from 0.15 to 18.0, from 0.002 to 13.1, and from 0.013 to 0.2 ng ml(-1), respectively. The calculated EDI for OTA in plasma ranged from 0.15 to 26 ng kg(-1) bw day(-1), higher than that obtained in urine (0.017-0.4 ng kg(-1) bw day(-1)). All these values are correlated with the range of EDI for OTA calculated from food products: 0.0001-25.2 ng kg(-1) bw day(-1).

Mycobiota and Natural Incidence of Aflatoxins, Ochratoxin A, and Citrinin in Indian Spices Confirmed by LC-MS/MS

Nine different Indian spices (red chilli, black pepper, turmeric, coriander, cumin, fennel, caraway, fenugreek, and dry ginger) commonly cultivated and highly used in India were analysed for natural occurrence of toxigenic mycoflora and aflatoxins (AFs), ochratoxin A (OTA), and citrinin (CTN) contamination. Aspergillus flavus and Aspergillus niger were the most dominant species isolated from all types of spices. Red chilli samples were highly contaminated with aflatoxins (85.4%) followed by dry ginger (77.7%). 56% Aspergillus flavus from red chilli and 45% Aspergillus ochraceus from black pepper were toxigenic and produced aflatoxins and ochratoxin A, respectively. Qualitative detection and quantitative detection of mycotoxins in spices were analyzed by ELISA and further confirmed by LC-MS/MS. Penicillium citrinum produced citrinin in red chilli, black pepper, coriander, cumin, fenugreek, and dry ginger samples. The highest amount of AFs was found in red chilli (219.6 ng/g), OTA was in black pepper (154.1 ng/g), and CTN was in dry ginger samples (85.1 ng/g). The results of this study suggest that the spices are susceptible substrate for growth of mycotoxigenic fungi and further mycotoxin production. This is the first report of natural occurrence of citrinin in black pepper and dry ginger from India.

Occurrence of ochratoxin a contamination and detection of ochratoxigenic Aspergillus species in retail samples of dried fruits and nuts

Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium and is a potential contaminant of a wide variety of food products. To determine the incidence of OTA contamination in dried fruits and tree nuts, retail packaged and bulk raisins, dates, figs, prunes, almonds, pistachios, and walnuts were collected from small and large supermarkets in seven areas of the United States between 2012 and 2014. Of the 665 samples analyzed, OTA was detected in 48 raisin samples, 4 fig samples, 4 pistachio samples, and 1 date sample. OTA contamination levels ranged from 0.28 to 15.34 ng/g in dried fruits and 1.87 to 890 ng/g in pistachios; two raisin samples and one pistachio sample exceeded the European Union regulatory limit of 10 ng/g. PCR detection of potential OTA-producing Aspergillus species revealed the presence of A. niger, A. welwitschiae, and A. carbonarius in 20, 7, and 7 of the 57 OTA-contaminated samples, respectively. However, OTA-producing A. carbonarius was isolated from only one raisin sample, and no other OTA-producing Aspergillus species were found. These results suggest that raisins are more frequently contaminated with low levels of OTA than are other dried fruits and nuts and that Aspergillus species are the likely source of that contamination.

Impact of maximum levels in European legislation on exposure of mycotoxins in dried products: case of aflatoxin B1 and ochratoxin A in nuts and dried fruits

In this study the impact of setting European criteria on exposure to aflatoxin B1 via nuts and figs and ochratoxin A via dried fruits is evaluated for the Belgian population, as an example of the European population. Two different scenarios were evaluated. In scenario 1 all collected literature data are considered, assuming that there is no border control nor legal limits in Europe. In the second scenario, contamination levels above the maximum limits are excluded. The results from scenario 1 demonstrated that if no regulation is in place, AFB1 and OTA concentrations reported in the analysed food can have potential health risk to the population. The estimated exposure of OTA for scenario 2 is below the TDI of 5 ng/kg BW⋅day, indicating that OTA concentrations accepted by EU legislation pose a low risk to the Belgian population. For AFB1, the MOE values of scenario 2 are above 10,000 and can be considered to be of low health concern, based on BDML10 for humans, except for figs (MOE = 5782). This means that for all matrices, with exception of figs, the maximum values of AFB1 in the European legislation are sufficient to be of a low health concern for consumers.

Developments in mycotoxin analysis: an update for 2009-2010

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2009 and mid-2010. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. New and improved methods for mycotoxins continue to be published. Immunological-based method developments continue to be of wide interest in a broad range of formats. Multimycotoxin determination by LC-MS/MS is now being targeted at the specific ranges of mycotoxins and matrices of interest or concern to the individual laboratory. Although falling outside the main emphasis of the review, some aspects of natural occurrence have been mentioned, especially if linked to novel method developments.