Aflatoxins levels in dried fruits and nuts from Rabat-Salé area, Morocco

The occurrence of aflatoxins (AFs) in dried fruits and nuts available in Rabat-Salé area (Morocco) was surveyed in this study. One hundred samples of dried fruits and nuts, purchased from retail shops and local markets from January to October 2006, were analyzed for AFs content by immunoaffinity (IAC) clean-up with liquid chromatography and fluorescence detection. Results showed that the incidences of total aflatoxins (AFT) and aflatoxin B1 (AFB1) in peanut, dried raisins, dried figs, walnut, and pistachio were 5%, 20%, 30%, 30% and 45% and 5%, 20%, 5%, 30% and 45%, respectively. The highest contamination levels of AFB1 were found in one walnut sample (2500 μg/kg) and one pistachio sample (1430 μg/kg). 5%, 20% and 20% of samples of pistachio, walnut and dried raisins exceeded the maximum tolerable limit (2 μg/kg) set for AFB1 by EU regulations. While 15% of dried figs samples were above the maximum limit (4 μg/kg) set by EU regulations for AFT. The present paper is the first report on the natural occurrence of AFs in dried fruits and nuts available in Rabat-Salé area in Morocco.     

Aflatoxin contamination in edible nuts imported in Qatar

Edible nuts imported in Qatar from June 1997 to December 1998 were anlaysed for aflatoxins. Eighty-one nut samples were analysed in the second half of 1997 and contamination was detected in 19 samples with total aflatoxin level varied from a low of about 0.53 to a high of 289 μg/kg. Aflatoxin contamination was detected in pistachios and peanuts, while other nuts such as almond, cashew nut, walnut and hazel nut were found free from aflatoxins. During 1998 testing was carried out only for pistachios and about 101 samples were analysed; contamination was detected in 48 samples with total aflatoxin level in the range of 1.2–275 μg/kg. In pistachios without shell level of contamination was very high (total aflatoxin 8.3–275 μg/kg) compared to pistachio with shell (total aflatoxin 1.2–75 μg/kg). Aflatoxin B₁ and B₂ were detected in all the contaminated samples of pistachios, whereas aflatoxin G₁ and G₂ were detected only in three samples of pistachios at the level of 0.8–1.9 μg/kg for aflatoxin G₁ and 0.4–1.3 μg/kg for aflatoxin G₂.     

Incidence of aflatoxins in commercial nuts in the holy city of Mekkah

The incidence of aflatoxins contamination in different nuts has been studied. Two hundred and sixty four samples of nuts were collected randomly from the main outlets across seven municipalities of the holy city of Mekkah. The samples were first screened for total aflatoxins using Aflatest immunoaffinity column (IAC) technique. The IAC results showed that 70 samples (26.5%) were contaminated with AFT in levels ranged between 1.0 and 110 μg/kg. The percentages of contamination of AFT in groundnuts were (18.4%), Pistachio (34%), walnuts (50%), cashew (15%), hazelnut (43%) and almond (17%). Only 23 samples (8.7%) had levels equal or exceeded the maximum tolerable limit for AFT in EU (4 μg/kg), and only 7 samples (2.65%) had exceeded the MTL in Saudi Arabia (20 μg/kg). The samples that exceeded MTL of Saudi Arabia were five pistachio sample (110, 45, 43, 34 and 30 μg/kg) and two peanut samples (100 and 28 μg/kg). Quantitative testing of total and individual AFs was conducted in selected samples from the IAC results with contamination levels exceeded the MTL of EU (23 samples) by using HPLC and fluorescence detection. AFB1 was detected in 22 out of 23 samples with contamination level in most of the positive samples exceeded the MTL set by EU regulations (2 μg/kg). The highest levels of AFB1 were detected in two sample of pistachio (411 and 126 μg/kg) and one sample of peanut (73.9 μg/kg). Aflatoxin G2 is detected in 5 out of 23 samples, pistachio (2), walnut (2) and hazelnut (1). While, B2 and G1 were detected in 17 samples in levels ranged between ND–10.7 μg/kg and ND–12.9 μg/kg, respectively.     

Aflatoxins in bulk and pre-packed pistachios sold in Spain and effect of roasting

The occurrence of aflatoxins in national and imported pistachios available in Aragón (NE Spain), purchased from commercial outlets during 2007, was surveyed. Thirty-two samples of roasted pistachios were analyzed for aflatoxins by immunoaffinity cleanup with liquid chromatography and fluorescence detection using post-column photochemical derivatization. Results showed that the incidence of aflatoxin B₁ and B₂ in pre-packed pistachios was 19% and 6%, while in bulk pistachios was 50% and 12.5%, respectively. All positive samples originated from Iran, while pistachios from USA, Turkey and Spain tested negative for aflatoxins. The low degree of contamination ranged from 0.12 to 0.29 μg/kg, and no sample exceeded the maximum permitted level for aflatoxins in pistachio nuts. Naturally occurring aflatoxin B₁ was not noticeably reduced by commercial roasting at 120 °C for 20 min.     

Aflatoxin occurrence in nuts and commercial nutty products in Malaysia

A total of 196 nuts and their products marketed in Penang, Malaysia were assessed for aflatoxins using a monitoring scheme consisting of enzyme-linked immunosorbent assay (ELISA) for rapid screening and reversed phase high performance liquid chromatography (HPLC) for quantification and confirmation. Thirty two out of 196 samples (16.3%): six raw groundnuts shelled, two roasted groundnut in shell, three roasted groundnut shelled, one walnut, four coated nut products, two peanut cakes (gung tang), 3 pounded groundnuts, one peanut slice, seven peanut butters, one bakery product and two confectionery were contaminated with aflatoxins, ranging in levels from 16.6 μg/kg up to 711 μg/kg (mean 17.2–350 μg/kg) for total aflatoxins.     

Incidence of aflatoxins contamination in dry fruits and edible nuts collected from Pakistan

During 2012–2015, a total of 624 samples of 13 different types of dry fruits and edible nuts were collected from retail shops and local markets of Pakistan. The collected samples were then studied for the occurrence of total aflatoxins (AFs) after immunoaffinity cleanup followed by HPLC coupled with fluorescence detector and post-column derivatization unit (Kobra Cell™). The seasonal variation of AFs was studied with respect to average temperature and relative humidity in Pakistan. LOD (S/N; 3:1) and LOQ (S/N; 10:1) of the utilized method were in the range of 0.09–0.12 and 0.30–42 μg/kg, respectively. About 165 (26%) samples were found contaminated, ranging from 0.22 to 30.11 μg/kg with a mean equivalent to 0.85 ± 0.26 μg/kg. In 459 (74%) samples, the AFs contamination was found lower than detectable limit corresponding to0.12 μg/kg. In 99 (15%) samples, the contamination range of AFs was 1–4 μg/kg. However, 28 (4%) samples exceeded the maximum tolerated limit (MTL) of 4 μg/kg as imposed by EU. However, 6 (1%) samples were found beyond the MTL of20 μg/kg as regulated by USA. Highly contaminated samples were found during the months of July, August and September. Achieved data highlighted the requirement of continuous monitoring and further investigation of AFs contamination in dry fruits/edible nuts under the authority of a definite systematic surveillance program adapted as a food safety measure.     

Studies on contamination level of aflatoxins in some cereals and beans of Pakistan

The occurrence of aflatoxins in some cereals and beans was surveyed in this study. One hundred and sixty samples of cereals and beans were purchased from retail shops and local markets of different locations in Pakistan. The samples were analyzed for total aflatoxins to using immune affinity (IAC) clean up with liquid chromatography and fluorescence detection. The results showed the percentage of contamination for total aflatoxins in the samples such as in; rice (25%), broken rice (15%), wheat (20%), maize (40%) barley (20%) and sorghum (30%), while in red kidney beans (20%), split peas (27%), chick pea (10%), cow pea (20%), and soybean (15%). The highest contamination levels of aflatoxins were found in one wheat sample (15.5 μg/kg), one maize sample (13.0 μg/kg) and one barley sample (12.6 μg/kg). Among all the contaminated samples, two rice, one rice broken, two wheat, three maize, two barley, one sorghum, one red kidney beans, one split peas and two soybeans were above the suggested limit for total aflatoxins (4 μg/kg), set by EU regulations.     

Aflatoxigenic fungi and aflatoxins occurrence in sultanas and dried figs commercialized in Brazil

The presence of aflatoxins, Aspergillus flavus and Aspergillus parasiticus in dried fruits was investigated. A total of 62 dried fruit samples were analyzed (24 black sultanas, 19 white sultanas and 19 dried figs). A total of 10 A. flavus isolates were found, nine in one white sultana sample (corresponding to 18% infection) and one isolate in dried figs (2%), and all of them were aflatoxin B₁ and B₂ producers. A. parasiticus was not found. Aflatoxins were detected in 3 of 19 (16%) white sultana samples analyzed and, the limits were not higher than 2.0 μg/kg. In dried figs 11 of 19 (58%) samples were contaminated with aflatoxins and, with exception of one sample that was contaminated with 1500 μg/kg of B₁ aflatoxin, the others had less than 2.0 μg/kg. Neither aflatoxigenic or aflatoxins contaminated black sultanas.     

A survey of the incidence and level of aflatoxin contamination in a range of locally and imported processed foods on Malawian retail market

Samples of locally (Malawian) processed and imported maize- and groundnut-based food products (peanut butters, roasted groundnuts, peanut based therapeutic foods, instant baby cereals, maize puffs and de-hulled maize flour) were collected from popular markets of Lilongwe City, Malawi. The samples were analysed in order to determine the frequency and extent of aflatoxin contamination, using immuno-affinity column and reversed-phase liquid chromatography with post-column photochemical derivatization and fluorescence detection. No aflatoxins were detected in all samples of imported baby cereal and locally processed de-hulled maize flour. However, all locally processed maize based baby foods had aflatoxins above EU maximum tolerable level of 0.1 μg/kg. In 75% of locally processed maize puffs, aflatoxins were detected at levels of up to 2 μg/kg. Peanut based therapeutic foods had aflatoxin level between 1.6 and 2.9 μg/kg, exceeding the EU tolerable maximum level (0.1 μg/kg) set for food for health purposes. Locally processed peanut butters had aflatoxins levels in the range of 34.2–115.6 μg/kg, which was significantly higher than their imported counterparts (<0.2–4.3 μg/kg). Samples of locally processed skinned and de-skinned roasted groundnuts had aflatoxins in range of 0.5–2.5 μg/kg and 0.6–36.9 μg/kg, respectively. These results highlight the need for rigorous monitoring of aflatoxins in commercially available processed products in order to reduce likely health risks associated with dietary aflatoxin intake.     

Fast and sensitive aflatoxin B1 and total aflatoxins ELISAs for analysis of peanuts,maize and feed ingredients

Aflatoxins are a group of carcinogenic compounds produced by Aspergillus fungi that can grow on different agricultural crops. Both acute and chronic exposure to these mycotoxins can cause serious illness. Due to the high occurrence of aflatoxins in crops worldwide fast and cost-effective analytical methods are required for the identification of contaminated agricultural commodities before they are processed into final products and placed on the market. In order to provide new tools for aflatoxin screening two prototype fast ELISA methods: one for the detection of aflatoxin B₁ and the other for total aflatoxins were developed. Seven monoclonal antibodies with unique high sensitivity and at the same time good cross-reactivity profiles were produced. The monoclonal antibodies were characterized and two antibodies showing IC₅₀ of 0.037 ng/mL and 0.031 ng/mL for aflatoxin B₁ were applied in simple and fast direct competitive ELISA tests. The methods were validated for peanut matrix as this crop is one of the most affected by aflatoxin contamination. The detection capabilities of aflatoxin B₁ and total aflatoxins ELISAs were 0.4 μg/kg and 0.3 μg/kg for aflatoxin B₁, respectively, which are one of the lowest reported values. Total aflatoxins ELISA was also validated for the detection of aflatoxins B₂, G₁ and G₂. The application of the developed tests was demonstrated by screening 32 peanut samples collected from the UK retailers. Total aflatoxins ELISA was further applied to analyse naturally contaminated maize porridge and distiller's dried grain with solubles samples and the results were correlated with these obtained by UHPLC-MS/MS method.     

Natural occurrence of aflatoxin B1 and aflatoxin M1 in “halva” and its ingredients

A total 431 samples including halva (56), pistachio (71), almond (63), semolina (69), cardamom (34), raisins (46), halva puri (39) and wheat powder (53) were analyzed using HPLC equipped with florescence detector. The results have shown that 32 (57%) samples of halva, 45 (63%) pistachio, 43 (68%) almond, 46 (67%) semolina, 21 (62%) cardamom, 19 (41%) raisins, 21 (54%) halva puri and 22 (42%) of wheat powder samples were found contaminated with AFB₁, and 11 (20%), 23 (32%), 34 (54%), 12 (17%), 11 (32%), 7 (15%), 9 (23%) and 11 (21%) samples, respectively were above the European Union permissible limit (2 μg/kg). The results have shown that 20 (59%) samples of halva that contained milk were found contaminated with AFM₁ and 3 (9%) samples were found above the recommended limit for AFM₁ i.e. 0.05 μg/kg. Limit of detection (LOD) and Limit of quantification (LOQ) for AFB₁ and AFM₁ were 0.04 μg/kg, 0.12 μg/kg, and 0.004 μg/L, 0.012 μg/L, respectively.     

Determination of aflatoxins in walnut sujuk and Turkish delight by HPLC-FLD method

This study aims to assess the risk of aflatoxins (AFs) in traditional confectionery products (walnut sujuk and Turkish delight) of Turkey. A high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used for the determination of AFs. Evaluation of the method showed good selectivity, linearity, recovery and precision. The limit of quantification (LOQ) ranged from 0.106 to 0.374 μg kg⁻¹. The expanded measurement uncertainty was less than 40% for all target analytes. The validated method was successfully applied to the determination of AFs in 112 traditional confectionery products containing nuts (hazelnuts and walnuts). AFs were detected in 43.8% of walnuts and 60.9% of hazelnuts used as ingredients in walnut sujuk and Turkish delight and at levels ranging from 0.58 to 15.2 μg kg⁻¹ and 0.43–63.4 μg kg⁻¹, respectively. This means that AFs levels in walnut sujuk and Turkish delight were up to levels of 6.1 and 9.5 μg kg⁻¹, respectively. Six walnut samples and twenty-one hazelnut samples were above the EU maximum limits (MLs) of 2 and 5 μg kg⁻¹ for aflatoxin B₁ (AFB₁), respectively.     

Survey of aflatoxins and ochratoxin a contamination in food products imported in Italy

In this study the levels of aflatoxins (AF B₁, B₂, G₁ and G₂) and ochratoxin A (OTA) were monitored in several food products imported in Italy with a high contamination risk. A total of 345 samples were collected from the Maritime Authority of Salerno Customs Port during the period from January 2008 to December 2009 and analyzed by immunoaffinity chromatography as clean-up, high performance liquid chromatography with fluorescence detection for quantification and tandem mass spectrometry for confirmation. The analytical methods were validated on different food matrices and meet the performance criteria set by EC Regulation No. 401/2006 for mycotoxin analysis. The results obtained in this survey showed that 7% of the total samples contained detectable levels of AFs and OTA, and 1.2% had AFs concentrations exceeding the maximum limits set by EU regulation. OTA was the most prevalent mycotoxin, with an incidence of 17.6% of samples analyzed for OTA. The highest detected levels were 23.70 μg kg^?1 of OTA in a green coffee sample and 70.69 μg kg^?1 of AFs in an apricot kernels sample. Among the food products analyzed, hazelnuts paste and dried vine fruits were the commodities mainly contaminated with AFs and OTA, respectively.     

Aflatoxins and ochratoxin A in dried chestnuts and chestnut flour produced in Italy

The occurrence of aflatoxins and ochratoxin A in chestnut products made in Italy was surveyed. Thirty-seven samples of chestnut flour and fourteen of dried chestnuts were collected from retail outlets located in northern Italy. After extraction and purification through an immunoaffinity column, aflatoxins and ochratoxin A were analysed using both HPLC-FLD and HPLC-MS/MS. The mycotoxin contamination found in this survey was widespread and remarkable. As regards aflatoxins, the incidence of aflatoxin B₁ was 62.2 and 21.4% in chestnut flour and dried chestnuts, respectively; in the same products, the percentage of samples exceeding the value of 2.0 μg kg⁻¹ for aflatoxin B₁ (maximum limit fixed by EC Regulation 165/2010 in dried fruits) was 24.3% and 7.1%. A widespread and high incidence of AFG₁ was also found (40.5%). The maximum values for aflatoxin B₁ and total aflatoxins were 67.88 and 188.78 μg kg⁻¹, respectively (chestnut flour sample). Ochratoxin A occurred in all samples, showing very high values (mean 12.38 and 13.63 μg kg⁻¹ for chestnut flour and dried chestnuts, respectively); the percentages of samples exceeding the limit of 10 μg kg⁻¹ (EU limits for dried vine fruit) were 64.9 and 42.8% for chestnut flour and dried chestnuts, respectively. The maximum value was 65.84 μg kg⁻¹ (dried chestnut sample).     

Monitoring of selected aflatoxins in brewing materials and beer by liquid chromatography/mass spectrometry

In 2008-2011 a total set of 333 samples of brewing raw materials and beer were analyzed for the presence of aflatoxins B₁, B₂, G₁ and G₂. The standard analytical method using high-performance liquid chromatography coupled to mass spectrometric detection with immunoaffinity column clean-up was applied. The method was validated. Limits of detection varied from 0.04 to 0.12 μg/kg in barley and malt, 0.08-0.58 μg/kg in different hop samples, 0.04-0.12 μg/kg in brewers’ yeast and spent grains and 1.5-4.7 ng/l in beer. Limits of quantification varied from 0.13 to 0.39 μg/kg in barley and malt, 0.25-1.94 μg/kg in different hop samples, 0.13-0.39 μg/kg in brewers’ yeast and spent grains and 5.1-15.2 ng/l in beer. In 7 of 216 samples of brewing raw materials (3.2%), aflatoxins were found at trace concentrations to 1.2 μg/kg. In 6 of 117 (5.1%) beer samples, aflatoxins were detected at concentrations to 31.0 ng/l. Values in barley and malt did not exceed the maximum allowable limit set by the European Union.     

Occurrence of mycotoxins in commercial infant formulas locally produced in Ouagadougou (Burkina Faso)

Cereals products enriched with leguminous or oleaginous are used in Burkina Faso as food complement or to avoid infant malnutrition. Infant formulas from cereals are consumed as food supplements after the weaning age. They are produced in Burkina Faso with a mixture of several cereals (maize, millet, rice, or sorghum), leguminous (bean), oleaginous (peanut, soya or sesame), sugar or salt and sometimes milk powder. The production is artisanal or semi-industrial. These infant foods from cereals should be free from mycotoxins and pathogenic bacteria. The objective of this work was to determine the occurrence of mycotoxins like aflatoxins, ochratoxin A and fumonisins in infant formulas and grains in Ouagadougou (Burkina Faso). The mycotoxins (aflatoxins, ochratoxin A and fumonisins) were determined by HPLC-FLD in 248 samples of infant formulas produced by the Recovery and Nutrition Education Centers (CRENs) and sold on the market places in Burkina Faso.Results showed that the majority of samples of infant formulas presented high levels of mycotoxins. The frequency of contaminated samples by aflatoxin B1, ochratoxin A and fumonisins in analyzed samples were 83.9% (167/199), 7.5% (15/199) and 1.5% (3/199), respectively. The highest values registered in infant formulas were 900, 6 and 3 times higher for aflatoxin B1 (EU limit: 0.1 μg/kg), ochratoxin A (EU limit: 0.5 μg/kg) and fumonisins (EU limit: 200 μg/kg), respectively, than the EU regulation limits (1881/2006). This study presents the first results concerning the safety assessment of infant formulas regarding mycotoxins in Burkina Faso.     

Natural occurrence of Aflatoxin B1 in peanut collected from Kinshasa,Democratic Republic of Congo

Aflatoxin B1 is a potent carcinogen to both animal and human health. Since peanut is a suitable substrate for aflatoxin production as well as an important oilseed and food in the Democratic Republic of Congo, the risk of consuming aflatoxin-contaminated peanuts is very high. This paper assessed the natural occurrence of aflatoxin B1 in raw peanuts collected in rural areas of Kinshasa, Democratic Republic of Congo. A total of 60 peanut samples were analyzed for aflatoxin B1, using thin layer chromatography. The results show that aflatoxin B1 levels increased from the dry season to the rainy season with values ranging from 1.5 to 390 and 12 to 937, respectively. 70% of the peanut samples from both seasons exceeded the maximum limit of 5 μg/kg prescribed by the World Health Organization (WHO). As the Democratic Republic of Congo is amongst African countries listed with high prevalence of liver cancer, continuous research on aflatoxin B1 is sought after.     

DNA Comet Assay––a rapid screening method for detection of irradiated cereals and tree nuts

Whole grains of some important cereals (wheat, buckwheat, maize, millet and oat) and some whole tree nuts (almonds, Brazil nuts, cashew nuts, peanuts, walnuts, hazelnuts, pistachio nuts and pine nuts) have been investigated for the identification of radiation treatment using microgel electrophoresis of single cells. This DNA Comet Assay is proposed as a rapid screening method for detection of irradiated foods, but is not radiation specific. Cereals and nuts were exposed to radiation doses of 0.5, 1 and 3 or 5 kGy covering the range for insect/pest disinfestation or for microbial control. After electrophoresis, irradiated cells from buckwheat, maize, millet and oat, and also from almonds, peanuts, walnuts and hazelnuts showed comets indicating stretching of fragmented DNA towards the anode. The size and shape of the comets were dose dependent. Non-irradiated samples of all cereals showed intact cells/nuclei in form of round stains or with short faint tails except for wheat, which showed only comets also in non-irradiated samples. For nuts like Brazil, cashew and pistachio nuts, suitable DNA material could not be extracted. In case of pine nuts, very few round intact cells were observed along with a majority of comets, making the screening difficult. Thus comet assay can be successfully used as a screening method for detection of radiation treatment of several cereals and nuts, however, the assay was not satisfactory for wheat and for Brazil nuts, cashew nuts, and pistachio nuts.     

Effect of packaging and storage conditions on quality of shelled walnuts

The present study investigated the effect of packaging and storage conditions on quality of raw shelled walnuts. Walnut kernels were packaged in: (a) low density polyethylene (LDPE), 55 μm in thickness in air, (b) polyethylene terephthalate||polyethylene (PET||PE), 70 μm in thickness under N₂, and (c) PET-SiO_x||PE pouches, 62 μm in thickness under N₂. Samples were stored either under fluorescent light or in the dark at 4 or 20 °C for a period of 12 months. Quality parameters monitored were peroxide value (PV), hexanal, 2-thiobarbituric acid (TBA), odor, and taste of product. PV ranged between 0.3 for fresh walnut kernels and 31.4 meq O₂/kg oil for walnuts packaged in PE pouches exposed to light after 12 months of storage. Respective values for hexanal were <28.5 μg/kg and 36.0 mg/kg and for TBA ca. 0.2 and 11 mg MDA/kg. Values for odor ranged between 0.2 for fresh walnut kernels and 5.7 for walnut kernels packaged in PE exposed to light after 12 months of storage at 20 °C. Respective values for taste were 0.7 and 6.8. Taste proved to be a more sensitive attribute than odor. Based on shelf life (taste) values and PV data it is proposed that the upper limit value for PV is close to 10.0 meq O₂/kg walnut oil. Respective limit values for hexanal are 1–2 mg hexanal/kg walnut and for TBA is 1–2 mg malondialdehyde/kg walnut. Walnuts retained acceptable quality for ca. 2 months in PE-air, 4–5 months in PET||PE-N₂ and at least 12 months in PET-SiO_x||PE-N₂ pouches at 20 °C, with samples stored in the dark retaining slightly higher quality than those exposed to light. The effect of parameters investigated followed the sequence: temperature > degree of O₂ barrier > lighting conditions.     

Aflatoxins in dates and dates products

A total of 153 samples of dates and dates products (date cookies, date cake and date halva) from Punjab and Khyber Pakhtunkhwa, Pakistan were evaluated for aflatoxins (AFs) using HPLC equipped with fluorescence detection. Thirty eight out of 96 samples (39.6%) of different date varieties and 18 out of 57 (31.6%) samples of date products contained AFs. The total mean level of AFs ranged between 2.90 to 4.96 μg/kg and 2.76 to 4.80 μg/kg in dates and dates products, respectively. About 16 and 20 samples of dates were found above the permissible level for AFB₁ and total AFs, respectively (i.e. 2 μg/kg, 4 μg/kg). Furthermore, two samples of date's cookies and one sample of date cake were found above the level of AFB₁ and total AFs and three and five samples of date halva were found above the recommended limit for AFB₁ and total AFs, respectively. The high occurrence of AFs may cause health hazards and limit exports.