Aflatoxins,ochratoxins and zearalenone in sorghum and sorghum products in Sudan

This survey examined 60 samples of sorghum and 30 samples of sorghum products from three states (Khartoum, Kordofan and Gadarif) of Sudan for aflatoxin B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2), ochratoxin A and B (OTA, OTB) and zearalenone (ZEN), using high performance liquid chromatography with fluorescence detection. The limits of detection and limits of quantification were in the range 0.01–0.6 µg kg^–1 and 0.03–2.0 µg kg^?1, respectively. The frequency of contaminated samples with AFB1 from Khartoum, Gadarif and Kordofan state was 38.1%, 22.2% and 23.8%, respectively. Only two samples of sorghum from Khartoum state were contaminated with OTA (3.3%). Concentrations of OTA and OTB were low and may not cause problems. No sample of sorghum or sorghum products was contaminated with ZEN. Some sorghum samples contained AFB1 concentrations above the European Union regulatory limits. The highest contaminated samples were found in Khartoum state.     

Survey on the occurrence of aflatoxins in rice from different provinces of Iran

Aflatoxins were surveyed in 256 rice samples taken from retail markets in different provinces of Iran during October 2007 and July 2008. A methanol/water (80?:?20,?v/v) mixture and an aflatoxin immunoaffinity column (IAC) were used for extraction and clean-up. Mycotoxins were determined using HPLC with fluorescence detection and post-column derivatization using a photo-ionization cell. Levels of contamination ranged 0.0–5.8?ng?g^?1 (mean, 1.4?ng?g^?1) and 0.1–6.3?ng?g^?1 (mean, 1.6?ng?g^?1) for AFB1 and total aflatoxins, respectively. AFB1 was detected in almost all samples. Results showed that 55 samples (21.5%) were contaminated with more than 2?µg?kg^?1 of AFB1, while seven samples (2.7 %) contained more than 4?µg?kg^?1 total aflatoxins. The calculated probable daily intake of AFB1 from rice for Iranians ranged 1.4–5.8?ng AFB1 per kg body weight per day for average consumers and, hence. exceeding the estimated provisional maximum tolerable daily intake.     

Aspergillus section Flavi and aflatoxins in dried figs and nuts in Algeria

The presence of Aspergillus section Flavi and aflatoxin (AF) contamination was investigated in 112 samples of peanuts, almonds and dried figs collected in Algeria. The occurrence of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in different commodities has been determined with a sensitive method based on high performance liquid chromatography (HPLC) coupled with fluorescence detection with post-column photochemical derivatisation. Analytical results indicated that 28 samples of peanuts, 16 samples of almonds and 26 samples of dried figs contained detectable levels of AFs. A total of 69 samples (61.6%) were contaminated with AFB1 ranging from the limit of quantification to 174 µg kg^?1. AFB2 was found in 12 samples (10.7%) and varied from 0.18 to 193 µg kg^?1. Seven samples revealed AF concentrations lower than the limit of quantification. Eleven peanut and fourteen dried fig samples exceeded the European maximum limits for AFB1.     

Survey of aflatoxins in retail samples of whole and ground black and white peppercorns

A total of 126 local and imported samples of commercial white and black pepper in Malaysia were analysed for aflatoxins B₁, B₂, G₁ and G₂ (AFB1, AFB2, AFG1, AFG2) content using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). An acetonitrile–methanol–water (17 : 29 : 54; v/v) mixture was used as a mobile phase and clean-up was using an immunoaffinity column (IAC). Seventy out of 126 (55.5%) samples were contaminated with total aflatoxins, although only low levels of aflatoxins were found ranging from 0.1 to 4.9 ng g^?1. Aflatoxin B₁ showed the highest incidence of contamination and was found in all contaminated samples. There was a significant difference between type of samples and different brands (p < 0.05). The results showed black peppers were more contaminated than white peppers.     

Aflatoxins contamination of maize in Serbia: the impact of weather conditions in 2015

ABSTRACT

In recent years climate changes recorded in temperate regions of Europe have led to aflatoxin (AF) contamination of maize. Thus, the aim of this study was to investigate the influence of weather conditions on levels of aflatoxin B₁ (AFB1), aflatoxin B₂ (AFB2), aflatoxin G₁ (AFG1) and aflatoxin G₂ (AFG2) in 180 maize samples collected from the main maize-growing regions (Western Ba?ka, North Banat, South Banat and Central Serbia) in Serbia after harvest in 2015. The concentrations of AFs were determined by a validated HPLC method with post-column derivatisation and fluorescence detection (HPLC-FLD). The presence of AFB1, AFB2, AFG1 and AFG2 was detected in 57.2%, 13.9%, 5.6% and 2.8% of maize samples in the concentration ranges of 1.3–88.8 µg kg^–1, 0.60–2.8 µg kg^–1, 1.8–28.5 µg kg^–1 and 2.1–7.5 µg kg^–1 respectively. The recorded smaller amount of precipitation and especially higher air temperatures during the summer of 2015 were favourable for AF production, which resulted in 32.2% and 21.1% of samples being unsuitable for human consumption, since AFB1 and the sum of AFs concentrations were above 5.0 and 10.0 µg kg^–1 respectively. Furthermore, the findings in this study indicate that the microclimate conditions in the investigated regions had a great influence on the contamination frequency of maize with AFs. The highest percentage of samples unsuitable for human consumption, considering both AFB1 and total AFs content were 72.5% and 51.5% respectively from Central Serbia, whilst the lowest percentages of 15.6% and 6.2% respectively were found in Western Ba?ka. These findings confirmed that maize should be continuously monitored in order to protect human and animal health from the harmful effects caused by AFs contamination.     

Aspergillus and aflatoxin in groundnut (Arachis hypogaea L.) and groundnut cake in Eastern Ethiopia

This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers’ management practices. A total of 160 groundnut seed samples from farmers’ stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g^?1 from 2013/2014 and 2014/2015 samples, respectively. The level of specific aflatoxin concentration varied between 0.1 and 2526 ng g^?1 for B₂ and B₁, respectively. Among contaminated samples of groundnut cake, 68% exhibited aflatoxin concentration below 20 ng g^?1, while as high as 158 ng g^?1 aflatoxin B₁ was recorded. The study confirms high contamination of groundnut products in East Ethiopia.     

A survey of aflatoxin in cotton seed in Iran by HPLC with on-line photochemical derivatisation and fluorescence detection

The aflatoxins content of 140 cotton seed samples were determined using high-performance liquid chromatography. Samples were obtained from wholesalers in Iran between May 2010 and June 2011. Aflatoxin B₁ gave the highest incidence of contamination and was found in 129 of the 139 samples. The highest concentration of aflatoxin was 14.4?ng?g^?1. Thirteen cotton seed samples (9.35%) were above one of the regulatory limits of the European Union (5?ng?g^?1), but no sample was above the highest EU limit and the safety limit recommended by the FDA (20?ng?g^?1) and regulatory limits of Iran (50?ng?g^?1) for total aflatoxin.     

Aflatoxin contamination in shrimp feed and effects of aflatoxin addition to feed on shrimp production

One hundred fifty samples of shrimp feed were collected from the eastern and southern regions of Thailand, and aflatoxins B1, B2, G1, and G2 (AFB1, AFB2, AFG1, and AFG2) in them were analyzed. AFB1 contamination ranged from a nondetectable level (< 0.003 ppb) to 0.651 ppb. Metabolites of AFB1 were less abundant than AFB1. To study the effects of aflatoxin in feed on shrimp production, black tiger shrimp were divided into four groups of 30 shrimp per group, tested in triplicate, and fed diets containing 0 (control), 5, 10, or 20 ppb of AFB1 for 10 consecutive days. After 7 or 10 days of consumption on each diet, the shrimp were weighed and sacrificed for laboratory examination. AFB1 and its metabolites were not detected in shrimp muscle. The mortality rate was slightly higher in the AFB1-treated groups than in the control group. The body weight of the surviving shrimp was decreased to 46 to 59% of the initial body weight in the AFB1-treated groups but not in the control group. Histopathological findings indicated hepatopancreatic damage by AFB1 with biochemical changes of the hemolymph. These results show that aflatoxin contamination in shrimp feed may cause economic losses by lowering the production of shrimp. Feed contaminated at the level of 20 ppb or lower (i.e., at the observed natural contamination level) may pose a very low risk, if any, to human health.     

Validation of the procedure for the simultaneous determination of aflatoxins ochratoxin A and zearalenone in cereals using HPLC-FLD

Method validation for quantitative analysis of aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEA) in cereals using HPLC with fluorescence detector (FLD) is described. Mycotoxins were extracted with methanol?:?water (80?:?20) and purified with a multifunctional AOZ immunoaffinity column before HPLC analysis. The validation of the analytical method was performed to establish the following parameters: specificity, selectivity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision (within- and between-day variability), stability, robustness, measurement of performance, and measurement of uncertainty. Calibration curves were linear (r?>?0.999) over the concentration range, from the LOQ to 26, 40 and 400?ng/g for AFs, OTA and ZEA, respectively. LOD and LOQ were 0.0125 and 0.05?ng/g for aflatoxin B1 (AFB1) and G1 (AFG1), 0.0037 and 0.015?ng/g for aflatoxin B2 (AFB2) and G2 (AFG2), as well as 0.05 and 0.2?ng/g for OTA and 0.5 and 2?ng/g for ZEA, respectively. The mean recovery values were 77–104% for different concentrations of AFs, OTA and ZEA in spiked cereal samples. Both intra- and inter-day accuracy and precision were within acceptable limits. This method was successfully applied for the simultaneous determination of mycotoxins for 60 cereal samples collected from Malaysian markets. Fifty per cent of the cereal samples were contaminated with at least one of these mycotoxins, at a level greater than the LOD. Only one wheat sample and two rice samples were contaminated with levels greater than the European Union regulatory limits for AFs and OTA (4 and 5?ng/g). The means and ranges of mycotoxins obtained for the cereal samples were 0.4?ng/g and 0.01–5.9?ng/g for total AFs; 0.18?ng/g and 0.03–5.3?ng/g for OTA; and 2.8?ng/g and 2.4–73.1?ng/g for ZEA, respectively. The results indicate that the method is suitable for the simultaneous determination of AFs, OTA and ZEA in cereals and is suitable for routine analysis.     

Mycoflora and natural occurrence of aflatoxin,cyclopiazonic acid,fumonisin and ochratoxin A in dried figs

Mycoflora, the mycotoxigenic properties of moulds, and natural contamination with mycotoxins such as aflatoxins (AFs), cyclopiazonic acid (CPA), fumonisin B₁ (FB₁) and ochratoxin A (OTA) were investigated in dried figs. Dry fig samples were collected from orchards during the drying stage in the Aegean Region of Turkey. Fungal isolates were identified using morphological, chemical as well as molecular methods. Mycotoxigenic characteristics of moulds were assessed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Mycotoxins except CPA (by TLC) were determined by HPLC. All the fig samples were contaminated with moulds and 94.7% contained one or more mycotoxigenic species. The most prevalent moulds present in dried figs belong to the Aspergillus section Nigri members, being 93.9% positive for the samples, followed by Fusarium spp., Aspergillus section Flavi and Penicillium spp. On the other hand, Fusarium spp. had the highest count and the number of fumonisin producing Fusarium was also high. A total of 48% of 115 dried fig samples contained OTA (range?=?0.1–15.3?ng?g^?1), 74.7% of the samples had FB₁ (range?=?0.05–3.65?mg?kg^?1), 10.0% of the samples had aflatoxin (range?=?0.1–763.2?ng?g^?1) and 24.3% of the samples were tentatively identified as being contaminated with CPA (range?=?25–187?ng?g^?1). Dried fig samples were contaminated with one (33.0%), two (47.0%), three (5.2%) and four mycotoxins (3.5%). A total of 11.3% of dried fig samples were not contaminated with any of the four mycotoxins. To the best of our knowledge, CPA and fumonisin have been found for the first time in dried figs.     

Effect of microwave heating during alkaline-cooking of aflatoxin contaminated maize

To evaluate the effectiveness of maize detoxification achieved with a modified tortilla-making process (MTMP), maize contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) at levels of 22.46, 69.62, and 141.48 ng/g (AFB(1)+ AFB(2)) was processed into tortillas. Aflatoxin content was determined according to the 991.31 AOAC official method. Based on the results obtained with spiked samples (0.78 to 25 ng/g), the mean recovery was 92%, with a standard error of 1.2, and a coefficient variation value of 4.4%. The MTMP caused 68, 80, and an 84% decrease in aflatoxin content, respectively. Extract acidification (as occurs during digestion) prior to mycotoxin quantification caused some reformation of the aflatoxin structure in tortillas (up to 3%). According to these results, the MTMP seems to be safe for decontamination since a low percentage of the initial aflatoxin concentration can be reverted to the original fluorescent form upon acidification. PRACTICAL APPLICATION: The potential presence of aflatoxins in maize destined for human consumption is a serious problem to the Mexican food supply, as these toxic compounds may persist during the traditional alkaline-process for tortilla elaboration. Consequently, new detoxification procedures are needed that eliminate or at least minimize the aflatoxin risk, through lowering aflatoxin concentration in maize-based products. Under these considerations, the use of MTMP is recommended, since it has definite advantages including non-production of wastewater and reduced energy/time consumption.     

Dietary mycotoxins binders: a strategy to reduce aflatoxin m1 residues and improve milk quality of lactating Beetal goats

Aflatoxin M1 (AFM1) is a metabolite of aflatoxin B1 (AFB1) and secreted in milk of animals that are kept on a moldy diet. AFB1 is produced by several toxigenic species of fungi. In this study, the comparative efficacy of two mycotoxin binders was evaluated in terms of reducing excretion of AFM1, total viable bacterial count and somatic cell count in milk obtained from goats fed with AFB1 contaminated diet. A total of 32 lactating Beetal goats were reared and divided into 4 equal groups: Animals of group A were kept as control, while those in groups B, C, and D were individually fed with AFB1 at 40 µg alone, 40 µg AFB1 along with mycotoxin binder Toxfin^® at 3 g kg^?1 of cotton seed cake, and 40 µg AFB1 along with mycotoxin binder Elitox^® at a dose rate of 1 g kg^?1 of cotton seed cake, respectively. Toxfin^® significantly decreased the excretion of AFM1 in goats’ milk by 49.57 % while Elitox^® non-significantly reduced the excretion of AFM1 in goats’ milk by 19.49 %. Total viable bacterial count in milk samples of group C and D, and somatic cell count in milk samples of group C did not reduce significantly. However, somatic cell count in milk samples of group D reduced significantly. We conclude that the addition of Toxfin^® in the moldy diet significantly reduce the excretion of AFM1 in animals’ milk and minimize the risk of mycotoxin toxicity to public health.     

Novel techniques for controlling the growth of and aflatoxin production by Aspergillus parasiticus in packaged peanuts

The effects of modified atmosphere packaging involving oxygen absorbents, storage temperature and packaging film barrier characteristics on the growth of and aflatoxin production by Aspergillus parasiticus in packaged peanuts was investigated. Mold growth was barely visible in air-packaged peanuts using a high gas barrier film (ASI) while extensive mold growth was observed in peanuts packaged under similar gaseous conditions using a low barrier film (ASIII). Incorporation of an oxygen absorbent (Ageless type S) inhibited mold growth in peanuts packaged in film ASI, while mold growth occurred in peanuts packaged with an absorbent/carbon dioxide generator (Ageless type G) in film ASI and in all absorbent-packaged peanuts in film ASIII. Aflatoxin B₁ production was detected at levels greater than the regulatory limit of 20 ng g^-1 in air-packaged peanuts using film ASI at 20°C and 25°C with the maximum level of aflatoxin (52·95 ng g^-1) being detected in air-packaged peanuts using film ASIII. However, aflatoxin production in all absorbent-packaged peanut samples was less than the regulatory level of 20 ng g^-1 irrespective of the barrier characteristics of the packaging film. Discoloration was more intensive in air-packaged peanuts in film ASIII especially at 25°C and 30°C than those packaged under similar or modified gaseous conditions using film ASI. This study has shown that oxygen absorbent technology is a simple and effective means of controlling the growth of and aflatoxin production by A. parasiticus. However, the effectiveness of these absorbents is dependent on the gas barrier properties of the packaging film surrounding the product.     

Effects of sodium metabisulphite,hydrogen peroxide and heat on aflatoxin B1 in lafun and gari - two cassava products

Sodium metabisulphite and hydrogen peroxide alone or in combination with heat (50–70°C) were found to be effective in degrading aflatoxin B1 (AFB1) in lafun and gari. Hydrogen peroxide (H₂O₂) at a concentration of 3 % in the aqueous phase gave a 12.5 % degradation of aflatoxin B1 in lafun and at 50°C, degradation levels of 25 % and 50 % were obtained with 6.0 and 9.0 % H₂O₂, respectively. When sodium metabisulphite was applied during the production of gari (a fermented cassava product heated to 50-70°C during production) AFB1 degradation levels were found to be 65.8 %, 60.9 %, 41.5 % and 36.6 %, respectively, for sodium metabisulphite levels of 1.0 %, 0.8 %, 0.5 % and 0.3 %.     

Fate of aflatoxin B(1) in contaminated corn gluten during acid hydrolysis

BACKGROUND: Aflatoxins are a group of mycotoxins that cause serious chronic disease outbreaks and contaminate several food products such as corn and its by‐product, corn gluten. The aim of the current study was to evaluate the effect of hydrochloric acid (HCl) on aflatoxin B₁ (AFB₁) degradation in contaminated corn gluten under different HCl concentrations, hydrolysis temperatures and hydrolysis times. RESULTS: During the wet milling process the highest AFB₁ level (45.68 µg kg^?1) (37.86%) was found in corn gluten fraction. Treatment with 1 mol L^?1 HCL at 110 °C resulted in degradation of AFB₁ by 27.6% (33.07 µg kg^?1) after 4 h and reached 42.5% (26.26 µg kg^?1) after 8 h. Increasing HCl concentration from 1 to 3 mol L^?1 HCl resulted in increased degradation of AFB₁, while complete degradation occurred in the presence of 5 mol L^?1 HCl after 4 h at 110 °C. Meanwhile, half‐life time of AFB₁ was recorded after 2 h at 100 °C and was < 2 h at 110 °C in the presence of 3 mol L^?1 HCl. CONCLUSION: It could be demonstrated that the manufacture of hydrolyzed vegetable protein is a suitable method for decontamination of aflatoxin in highly contaminated grains, especially gluten fractions. The hydrolysis reaction could be considered in terms of first‐order reaction kinetics of AFB₁ degradation. Copyright © 2010 Society of Chemical Industry     

Effect of different ozone treatments on aflatoxin degradation and physicochemical properties of pistachios

This study evaluated the efficiency of ozone for the degradation of aflatoxins in pistachio kernels and ground pistachios. Pistachios were contaminated with known concentrations of aflatoxin (AF) B₁, B₂, G₁ and G₂. Pistachio samples were exposed to gaseous ozone in a chamber at 5.0, 7.0 and 9.0 mg L^?1 ozone concentrations for 140 and 420 min at 20 °C and 70% RH. Aflatoxin degradation was determined by high performance liquid chromatography (HPLC). The efficiency of ozone for aflatoxin degradation in pistachios increased with increasing exposure time and ozone concentration. The results indicated that AFB₁ and total aflatoxins could be reduced by 23 and 24%, respectively, when pistachio kernels were ozonated at 9.0 mg L^?1 ozone concentration for 420 min. Only a 5% reduction in AFB₁ and total aflatoxin levels could be achieved for ground pistachios under the same conditions. No significant changes occurred in pH, color, moisture content and free fatty acid values of pistachio kernels and ground pistachios. Fatty acid compositions of pistachios did not change significantly after the ozonation treatments. No significant changes were found between sweetness, rancidity, flavor, appearance and overall palatability of ozonated and non‐ozonated pistachio kernels. Significant changes were observed in the organoleptic properties of ground pistachios, except rancidity, after 5.0 mg L^?1 ozone treatment for 140 min. Ozonation was found to be more effective for degrading aflatoxins in pistachio kernels than ground pistachios. Copyright © 2006 Society of Chemical Industry     

Increased aflatoxin contamination of dried figs in a drought year

Dried figs (4917 samples) destined for export from Turkey to the European Union were collected between September and December during the very dry crop year of 2007 and tested for aflatoxins B₁, B₂, G₁ and G₂ by immunoaffinity column clean-up and reverse-phase high-performance liquid chromatography (RP-HPLC). While 32% of the samples contained detectable levels of total aflatoxins, 9.8% of them exceeded the European Union limits. Aflatoxin levels were in the range of 0.2–259.46 µg kg^?1 and 2.04–259.46 µg kg^?1 for all samples and samples that exceeded the limits, respectively. A substantial increase in the incidence of aflatoxins was observed in 2007 compared with previous years, most likely due to the drought stress, high temperatures and low relative humidity encountered during the period from January to September of that year. In 2007, the mean temperature was 1–2°C higher, there was 300 mm less total rain, and the mean relative humidity was 10–15% lower than in 2002–06. The average concentration of individual aflatoxins present in the samples was quantified to determine whether the drought conditions promoted certain types of aflatoxins. Among the contaminated samples, aflatoxin B₁ occurred in 97% of the contaminated samples, followed by G₁ in 47%, B₂ in 24%, and G₂ in 6% of samples. Concentrations of individual aflatoxins exhibited great variability among the samples but were not significantly different from those reported in previous studies, which were conducted under conditions without drought and high temperatures.     

Aflatoxin determination in commonly consumed foods in Tunisia

BACKGROUND: To investigate natural aflatoxin occurrence, a total of 180 samples of different foods widely consumed in Tunisia were analysed by an in‐house‐validated high‐performance liquid chromatography method including affinity column clean‐up and post‐column bromination techniques. RESULTS: The method used appeared to be rapid, selective and reproducible, and its performances were established. Detection limits were 0.05 ng g^?1 for aflatoxin B1 and 0.025 ng g^?1 for aflatoxins B2, G1 and G2. Aflatoxins were detected in all investigated commodities except rice, with an overall contamination frequency of 34.4% and concentrations ranging from 0.1 to 40.6 ng g^?1. Aflatoxin B1 was found in all contaminated samples. Sorghum, spices and nuts were most contaminated. CONCLUSION: This study has provided an effective analytical method for the reliable determination of aflatoxins in food samples. Over one‐third of the samples investigated were contaminated with aflatoxins. Sorghum, spices and nuts were most contaminated, whereas rice showed no contamination. Copyright © 2010 Society of Chemical Industry     

Comparison of homogenization techniques and incidence of aflatoxin contamination in dried figs for export

To determine differences in mean aflatoxin contamination and subsample variance from dry and slurry homogenizations, 10 kg of six different, naturally contaminated dried fig samples were collected from various exporting companies in accordance with the EU Commission Directive. The samples were first dry-mixed for 5 min using a blender and sub-sampled seven times; the remainder was slurry homogenized (1 : 1, v/v) and sub-sampled seven times. Aflatoxin B₁ and total aflatoxin levels were recorded and coefficient of variations (CV) computed for all sub-samples. Only a small reduction in sub-sample variations, indicated by the lower CV values, and slight differences in mean aflatoxin B₁ and total aflatoxin levels were observed when slurry homogenization was applied. Therefore, 7326 dried figs, destined for export from Turkey to the EU and collected during the 2008 crop year, were dry-homogenized and tested for aflatoxins (B_1, B_2, G₁ and G₂) by immunoaffinity column clean-up using RP-HPLC. While 34% of the samples contained detectable levels of total aflatoxins (0.20–208.75 µg kg^?1), only 9% of them exceeded the EU limit of 4 µg kg^?1 in the range 2.0–208.75 µg kg^?1, respectively. A substantial increase in the incidence of aflatoxins was observed in 2008, most likely due to the drought stress experienced in Aydin province as occurred in 2007.