Activated carbons as potentially useful non-nutritive additives to prevent the effect of fumonisin B1 on sodium bentonite activity against chronic aflatoxicosis

Aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) are mycotoxins that often co-occur in feedstuffs. The ingestion of AFB₁ causes aflatoxicosis in humans and animals. Sodium bentonite (NaB), a cheap non-nutritive unselective sequestering agent incorporated in animal diets, can effectively prevent aflatoxicosis. Fumonisins are responsible for equine leukoencephalomalacia and porcine pulmonary oedema, and often have subclinical toxic effects in poultries. Fumonisin B₁ and aflatoxin B₁ are both strongly adsorbed in vitro on sodium bentonite. Co-adsorption studies, carried out with a weight ratio of FB₁ to AFB₁ that mimics the natural occurrence (200:1), showed that FB₁ greatly decreases the in vitro ability of NaB to adsorb AFB₁. The ability of two activated carbons to adsorb FB₁ was also investigated. Both carbons showed high affinity for FB₁. A complex behaviour of the FB₁ adsorption isotherms with pH was observed. In vitro results suggest that under natural contamination levels of AFB₁ and FB₁, a mixture of activated carbon and sodium bentonite might be potentially useful for prevention of sub-acute aflatoxicosis.     

Aflatoxin B1 in sesame seeds and sesame products from the Greek market

Aflatoxin B₁ (AFB₁) is considered as the most potent liver carcinogen for humans. A method for determination in sesame seeds was developed. AFB₁ was extracted by methanol-water, cleaned by immunoaffinity columns and determined by high-performance liquid chromatography with fluorescence detection. The recovery factor and the limit of detection (LOD) of AFB₁ in sesame seeds were 111.5% and 0.02 ng g^?1, respectively. Thirty samples of sesame products were examined for the presence of AFB₁. After analysis, 77.6% of samples were found to be contaminated. Eight samples exceeded the European Union (EU) limit (2 µg AFB₁ kg^?1). In 15 samples, AFB₁ was below the EU limit. Seven samples remained below the LOD. The most contaminated (14.49 ng AFB₁ g^?1) sample was unpeeled packaged sesame seeds. In all samples, aflatoxigenic Aspergilli fungi as well as the risk for AFB₁ presence in sesame seed was investigated.     

Degradation of aflatoxin B1 in peanut meal by electron beam irradiation

The effects and safety of electron beam irradiation (EBI) treatment on the detoxification of aflatoxin B₁ (AFB₁) in the peanut meal were evaluated in this article. The AFB₁ degradation was predominantly affected by both initial AFB₁ and water concentrations. The degradation of AFB₁ in the selected concentrations (0.5–5 ppm) was proven to follow pseudo first-order reaction kinetics (R² > 0.95). The AFB₁ degradation was faster when the initial concentration was 5 ppm and the moisture content was 21.47%, in comparison with the initial concentration of 1 ppm and 0.5 ppm and the moisture content of 14.32% and 8.74%, respectively. The Ames and cytotoxicity tests were employed to evaluate the residual toxicity of EBI-treated peanut meal. The mutagenic activity of EB-treated samples was completely lost compared with that of untreated samples and the degradation products in peanut meal has almost no cell toxicity.     

Aflatoxin B1 in peanut oil from Western Guangdong,China, during 2016–2017

Aflatoxin B₁ (AFB₁) occurrence in peanut oil samples randomly collected from family workshops in western Guangdong during 2016–2017 (n = 427) was surveyed. AFB₁ content was screened by enzyme-linked immunosorbent assay (ELISA) protocol and analytically confirmed with an UPLC-MS/MS method. The limit of detection of the ELISA method was 1.08 μg kg^?1. The recovery values ranged from 84.4 to 92.6% with relative standard deviations of 2.2 to 4.8%. AFB₁ was quantified in 47 samples (22.5%) with a range of 15.4–49.9 μg kg^?1 in 2016 and in 33 samples (15.1%) with 8.8–22.2 μg kg^?1 in 2017, respectively. The AFB₁ contamination in peanut oil was season-depended in western Guangdong with the worst case in spring (24.2–37.9%). Overall, a significant reduction of AFB₁ occurrence was observed in western Guangdong after 2016. It is advisable to control AFB₁ in bulk and self-pressed oil from family workshops and regulate it mandatorily if necessary.     

Aflatoxin M1 in raw milk and aflatoxin B1 in feed from household cows in Singida,Tanzania

Aflatoxin M₁ (AFM₁) contamination in raw milk from household cows fed with sunflower seedcakes or sunflower-based seedcake feeds was determined in 37 milk samples collected randomly from different locations in Singida region, Tanzania. Aflatoxin B₁ (AFB₁) contamination in sunflower-based seedcake feed was determined in 20 feed samples collected from the same household dairy farmers. The samples were analysed by RP-HPLC using fluorescent detection after immunoaffinity column clean-up. Recoveries were 88.0% and 94.5%, while the limits of detection (LOD) were 0.026 ng mL^?1 and 0.364 ng g^?1 for AFM₁ and AFB₁, respectively. Of the analysed cow’s milk samples, 83.8% (31/37) contained AFM₁, with levels ranging from LOD to 2.007 ng mL^?1, exceeding both the European Commission (EC) and Tanzania Food and Drug Authority (TFDA) limit of 0.05 ng mL^?1. Of the contaminated samples, 16.1% exceeded the Codex Alimentarius limit of 0.5 ng mL^?1. AFB₁ was present in 65% (13/20) of the feed samples with levels ranging from LOD to 20.47 ng g^?1, 61.53% exceeding the TFDA and EC maximum limits of 5 ng g^?1 for complete dairy animal feed. The observed AFM₁ and AFB₁ contamination necessitates the need to raise awareness to dairy farmers in Tanzania to safeguard the health of the end-users.     

Aflatoxin B1 in betel nuts (Areca catechu L.) imported to Pakistan from different regions of South Asia

Aflatoxin B₁ (AFB₁) levels were evaluated in betel nuts (Areca catechu L.) being imported to Pakistan during 2010–2011. In total, 278 betel nut samples (India = 21, Indonesia = 51, Sri-Lanka = 34 and Thailand = 172) were received from the Department of Customs and were analysed by thin layer chromatography (TLC). All Indian origin betel nuts showed AFB₁ contamination ranging from 11.7–262.0 µg kg^?1 with a mean of 92.5 µg kg^?1. Among Indonesian and Sri Lankan shipments, 80.4% and 73.5% betel nuts were contaminated with AFB₁ ranging between 3.3–39.2 and 6.5–103.4 µg kg^?1 with a mean of 11.6 and 35.0 µg kg^?1, respectively. However, only 30.2% of Thailand origin samples showed AFB₁ contamination ranging 3.3–77.0 µg kg^?1 with a mean of 6.6 µg kg^?1. The widespread occurrence of AFB₁ increases the hazard associated with betel nuts. Thus, strict control is a pre-requisite for the production and import/export of psychoactive substances as betel nuts.     

Reduction of aflatoxin B1 contamination in wheat by various cooking treatments

To investigate the effects of various cooking treatments such as washing, heating and steaming on the reduction of aflatoxin toxicity, a simultaneous analytical method for aflatoxin B₁, B₂, G₁, G₂ was established using high performance liquid chromatography (HPLC) with a fluorescence detector. The levels of aflatoxin B₁ (AFB₁) spiked in wheat—three varieties of United States (US) wheat and two varieties of Korean wheat—were analyzed according to washing time and heating temperature. Reduction of AFB₁ toxicity was directly proportional to washing time in both Korean and US wheat. The concentration of AFB₁ was reduced more by heating than washing treatment. The level of AFB₁ in dried wheat was decreased to 50% and 90% by heating at 150 and 200 °C, respectively. However, the reduction of AFB₁ in wet wheat in which water (10%) was intentionally added was higher by heating than in dried wheat. The reduction of AFB₁ was increased by 8% and 23% in 10% water-added US wheat (soft red white wheat) and Korean wheat (Anbaekmil) compared to dried US and Korean wheat, respectively, through heat treatment. Traditional processing used in Korean foods such as Sujebi (a soup with wheat flakes) and steamed bread caused 71% and 43% decrease in aflatoxin B₁ content.     

Aflatoxin B1 and sterigmatocystin survey in beer sold in China

ABSTRACT

A total of 101 samples of beer from the Chinese market were analysed for the presence of aflatoxin B₁ (AFB₁) and sterigmatocystin (STC), using methods based on liquid chromatography–tandem mass spectrometry. The limit of quantification and the limit of detection in beer were 0.1 and 0.03 µg/kg, respectively. Recoveries of AFB₁ and STC from spiked beer samples were 97.8–103.6% and 92.7–102.1%, respectively. None of the beer purchased samples were contaminated with AFB₁ or STC.     

Aflatoxin B1-degrading activity from Bacillus subtilis BCC 42005 isolated from fermented cereal products

ABSTRACT

Aflatoxin B₁ is a naturally occurring mycotoxin that is produced as secondary metabolite by Aspergillus spp., especially A. flavus and A. parasiticus. This is the most severe toxin due to its carcinogenic, mutagenic, and teratogenic properties. Hence, methods for toxin degradation have been received increasing interest from both scientific communities and industries. In this study, 32 isolates of Bacillus spp. from various fermented cereal products were screened for their aflatoxin B₁ degradation ability. The results indicated the extracellular fraction of Bacillus subtilis BCC 42005 isolated from Iru (African locust bean) potentially possessed aflatoxin B₁-degrading ability. The maximum activity of the active fraction was at 50°C and pH 8.0. The activity was stable in a wide range of pH (5.0–8.0) and temperature (25–60°C). The aflatoxin B₁-degrading mechanisms of this strain may be possibly involved by enzyme(s). This extracellular fraction was not toxic at IC₅₀ 4 mg/ml and it can be combined with water as a soaking agent for maize, which results in 54% of aflatoxin B₁ reduction after contact time 120 min. Hence, the extracellular fraction of Bacillus subtilis BCC 42005 can be further applied as an effective soaking agent in a pretreatment process with a practical and easy-to-implement condition and also probably used to reduce the aflatoxin B₁ contamination in other foods and feeds commodities.     

Aflatoxin B1 in eggs and chicken livers by dispersive liquid–liquid microextraction and HPLC

A rapid, low-cost and simple technique has been developed for the determination of aflatoxin B₁ (AFB₁) in eggs and livers using high-performance liquid chromatography (HPLC) with UV detection. In this study, the presence of AFB₁ was investigated in 150 eggs and 50 chicken livers from the local market of Tabriz, Iran. AFB₁ was extracted with a mixture of acetonitrile:water (80:20) and cleaned up by dispersive liquid–liquid microextraction which is a very economical, fast and sensitive method. AFB₁ was quantified by HPLC-UV without need for any complex derivatisation in samples to enhance the detection. The results showed that 72% of the liver and 58% of the egg samples were contaminated with AFB₁ ranging from 0.30 to 16.36 µg kg ^?1. limit of detection and limit of quantification for AFB₁ were 0.08 and 0.28 µg kg ^{? 1}, respectively. The proposed method is suitable for fast analysing of AFB₁ in egg and liver samples.     

Aflatoxins in sunflower seeds and unrefined sunflower oils from Singida,Tanzania

A total of 61 samples comprising sunflower seeds (40) and unrefined sunflower oils (21) samples collected randomly from Singida, Tanzania were analysed by Reverse Phase-high performance liquid chromatography (RP-HPLC). 15% (6/40) of the seed samples were contaminated with aflatoxin B₁ ranging from limit of detection (LOD) to 218 ng g^?1 with three of them exceeding the European Commission/European Union (EC/EU) and Tanzania Bureau of Standards (TBS)/Tanzania Food and Drug Authority (TFDA) maximum limits of 2 ng g^?1 for AFB₁ in oilseeds. The levels of total aflatoxins (AFT) in seeds ranged from LOD to 243 ng g^?1. Other aflatoxins, except AFG₂, were also detected. For the unrefined sunflower oils, the levels of AFB₁ ranged from LOD to 2.56 ng mL^?1. About 80.9% (17/21) of the analysed oil samples contained AFB₁ of which 17.65% (3/17) exceeded the EC/EU and TBS/TFDA maximum limits of 2 ng mL^?1. Other aflatoxins were also detected in the oils. The measured levels indicate there is a need for food quality education among food processors.     

Efficiency and safety evaluation of photodegradation of Aflatoxin B1 on peanut surface

A photodegradation study of Aflatoxin B₁ (AFB₁) on peanut surface was performed under UV irradiation at different UV irradiation intensities. With an initial quantity of 10 ng of AFB_1, it can be degraded thoroughly within 80 min under the intensity of 800 μw cm^?2. The photodegradation pathway of AFB₁ on the peanut surface was proposed. Mutagenesis and cytotoxicity were assessed after exposure to different concentrations of AFB₁ and the mixtures of photodegradation products on the peanut surface. The results of the Ames and in vitro cytotoxicity assay, providing clues to the assessment of safety issues of UV method applied in AFB₁ decontamination, indicate that photodegradation products on the peanut surface has no toxicity, which can be explained by the differences in the chemical nature of the test compounds before and after UV irradiation.     

Natural co-occurrence of ochratoxin A,ochratoxin B and aflatoxins in Sicilian red wines

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂ (OTA, OTB, AFB₁, AFB₂, AFG₁, AFG₂) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l^–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG₁, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB₁, AFB₂, AFG₁ and AFG₂ at two different levels. The limits of detection (LODs) in wines were 0.02 µg l^–1 for OTA, 0.04 µg l^–1 for OTB, 0.03 µg l^–1 for AFG₁, AFG₂ and AFB₂, and 0.05 µg l^–1 for AFB₁. A good correlation was found, with good performances in term of precision for the method.     

Moulds and mycotoxins detected in the regional speciality fermented sausage ‘slavonski kulen’ during a 1-year production period

ABSTRACT

This study investigated the surface-to-interior mycotoxin contamination of the regional speciality meat product ‘slavonski kulen’ that occurred during a 12-month period and identified moulds present on its surface during the final production stage. In total, 15 pieces of slavonski kulen were produced and sampled at production months 0, 3, 6, 9 and 12 (three samples per piece). Concentrations of aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) were determined using the ELISA method, while the identification of moulds made use of both traditional and molecular methods. A 12-month-long production of dry-fermented sausages under controlled conditions that did not include product cleaning at any point caused significant mycotoxin contamination, with determined mean AFB₁ and OTA concentrations of 11.79 ± 2.34 and 16.13 ± 3.32 µg kg^–1, respectively. Significantly higher mycotoxin levels were observed in the external layers of the products in comparison with their interior and, even more so, central parts. In total, five Penicillium species (P. polonicum, P. terrigenum, P. solitum, P. jugoslavicum and P. corylophilum) and two Aspergillus species (A. versicolor and A. sydowii) were isolated. Moulds responsible for the production of AFB₁ and OTA in the later production stages had probably been overgrown by non-toxicogenic moulds, so that the former did not last until the end of the sausages’ production process and were therefore not identified.     

Short communication: Investigation of aflatoxin M1 levels in infant follow-on milks and infant formulas sold in the markets of Ankara,Turkey

Aflatoxins are fungal toxins known to be carcinogenic and are classified as food contaminants. This study was performed to investigate aflatoxin (AF) M₁ levels in baby foods sold in Ankara (Turkey) and to evaluate the obtained results according to the Turkish Food Codex (TFC). For this purpose, a total of 84 baby food samples (50 follow-on milks and 34 infant formulas) were obtained from different markets in Ankara and the presence of AFM₁ in the samples was analyzed by ELISA. In 32 (38.1%) of 84 infant food samples, the presence of AFM₁ was detected in concentrations ranging between 0.0055 and 0.0201 µg/kg. The mean level (±standard error) of AFM₁ was found to be 0.0089 ± 0.0006 µg/kg in positive infant follow-on milks. Aflatoxin M₁ was detected in only 1 infant formula sample (2.94%) at a concentration of 0.0061 µg/kg. The extrapolated levels of AFB₁ contamination in feedstuffs were calculated based on levels of AFM₁ in baby food samples. The data estimating AFB₁ contamination in dairy cattle feedstuff indicate that contamination may range from 0.3410 to 1.2580 µg/kg, with the mean level (±standard error) being 0.5499 ± 0.0385 µg/kg, which is lower than the level set by the TFC and European Union regulations (5 µg/kg). According to the obtained results, the levels of AFM₁ in analyzed samples were within the allowed limit (0.025 µg/kg) set in the TFC. Low levels of AFM₁ in infant follow-on milks and infant formula samples obtained during the study do not pose a health risk to infants.     

Modeling and Optimization of Enzymatic Degradation of Aflatoxin B1 (AFB1) in Red Chili Powder Using Response Surface Methodology

Response surface methodology was used to optimize the peroxidase-catalyzed enzymatic degradation of aflatoxin B₁ (AFB₁) from red chili powder. Twenty experiments were carried out using central composite rotatable design with three independent variables (enzyme concentration, substrate or AFB₁ concentration, and incubation time) and single response (% aflatoxin B₁ degradation). The optimum conditions achieved after numerical and graphical optimizations for maximum percent degradation were: AFB₁ (31.5 nM), enzyme (13.5 U/nM AFB₁), and time (26 h). The actual percent degradation achieved at these optimum conditions was 70.0% and predicted 74.5%. The reduced quadratic model developed for the experimental data was found adequate to describe the relationships between the operating variables (Model F = 21.61, p < 0.001; F _lof = 3.63, p > 0.05). The robustness of the model was tested by confirmation experiments, and difference was found insignificant between the actual and predicted values as confirmed by two-tailed t test (α = 0.05). The hepatotoxic effect of the AFB₁ pre- and post-detoxification was tested on Wistar rats. The detoxified powder was also tested for changes in ascorbic acid, β-carotene, ASTA color value, and capsaicin content. Capsaicin was resistant to enzymatic degradation under specified conditions, but loss of around 15% was reported in color and β-carotene content; the loss in ascorbic acid was 10%.     

Inhibitory effect of Cynara cardunculus L. extract on aflatoxin B1 production by Aspergillus parasiticus in sesame (Sesamum indicum L.)

Aflatoxin B₁ has been considered as the most potent liver carcinogen for humans. One factor that stimulates the production of aflatoxins in oilseed products, such as sesame seeds and their products is the presence of high levels of fatty acids. This work presents further evidence that sesame is a favorable substrate for aflatoxin B₁ production by Aspergillus parasiticus. Moreover, the use of wild artichoke (Cynara cardunculus L.) extract was examined showing inhibition of aflatoxin B₁ production in both sesame and yeast extract sucrose medium, inoculated with A. parasiticus. More specifically, the inhibition of aflatoxin B₁ production by A. parasiticus in sesame seeds paste was 99.6% and in yeast extract sucrose medium it was 99.4%.     

Elucidation of antifungal toxicity of Callistemon lanceolatus essential oil encapsulated in chitosan nanogel against Aspergillus flavus using biochemical and in-silico approaches

ABSTRACT

The antifungal and aflatoxin B₁ (AFB₁) inhibitory effect of chemically characterised Callistemon lanceolatus essential oil (CLEO), chitosan nanoparticles, and CLEO loaded chitosan nanoparticles (CLEO-ChNPs) were investigated. Scanning electron microscope observation exhibited the spherical shape of prepared CLEO-ChNPs with an average range of 20–70 nm. An in-vitro release study revealed the controlled volatilisation of CLEO from CLEO-ChNPs. The CLEO-ChNPs caused complete inhibition of growth (4.5 µl/ml) and AFB₁ (4.0 µl/ml) production by A. flavus at a low dose compared to free CLEO (5.0 µl/ml). The antifungal and AFB₁ inhibitory toxicity of CLEO-ChNPs were elucidated using biochemical (effect on ergosterol biosynthesis, membrane cations, mitochondrial membrane potential, C-sources utilisation and cellular methylglyoxal level) and in-silico (interaction with the gene product Erg 28, Cytochrome c oxidase subunit Va, Omt-A, Ver-1, and Nor-1) approaches.     

Intervention trial with calcium montmorillonite clay in a south Texas population exposed to aflatoxin

South Texas currently has the highest incidence of hepatocellular carcinoma (HCC) in the United States, a disease that disproportionately affects Latino populations in the region. Aflatoxin B₁ (AFB₁) is a potent liver carcinogen that has been shown to be present in a variety of foods in the United States, including corn and corn products. Importantly, it is a dietary risk factor contributing to a higher incidence of HCC in populations frequently consuming AFB₁-contaminated diets. In a randomised double-blind placebo controlled trial, we evaluated the effects of a 3-month administration of ACCS100 (refined calcium montmorillonite clay) on serum AFB₁–lysine adduct (AFB-Lys) level and serum biochemistry in 234 healthy men and women residing in Bexar and Medina counties, Texas. Participants recruited from 2012 to 2014 received either a placebo, 1.5 g or 3 g ACCS100 each day for 3 months, and no treatment during the fourth month. Adverse event rates were similar across treatment groups and no significant differences were observed for serum biochemistry and haematology parameters. Differences in levels of AFB-Lys at 1, 3 and 4 months were compared between placebo and active treatment groups. Although serum AFB-Lys levels were decreased by month 3 for both treatment groups, the low dose was the only treatment that was significant (p = 0.0005). In conclusion, the observed effect in the low-dose treatment group suggests that the use of ACCS100 may be a viable strategy to reduce dietary AFB₁ bioavailability during aflatoxin outbreaks and potentially in populations chronically exposed to this carcinogen.     

Negligible effects of tryptophan on the aflatoxin adsorption of sodium bentonite

The main objective of this study was to determine if the competitive adsorption of tryptophan (Trp) and aflatoxin B₁ (AFB₁) could potentially affect the ability of a sodium bentonite (NaB) to prevent aflatoxicosis in monogastric animals. The adsorption of Trp and AFB₁ on this adsorbent is fast and could be operating on the same time-scale making competition feasible. In vitro competitive adsorption experiments under simulated gastrointestinal conditions were performed. A high affinity of the clay for Trp and NaB was observed. The effect of an excess of KCl to mimic the ionic strength of the physiological conditions were also investigated. A six-times decrease in the Trp surface excess at saturation was observed. A similar behaviour was previously found for AFB₁ adsorption. Taking into account the amount of Trp adsorbed by the clay and the usual adsorbent supplementation level in diets, a decrease in Trp bioavailability is not expected to occur. Tryptophan adsorption isotherms on NaB were ‘S’-shaped and were adjusted by the Frumkin–Fowler–Guggenheim model. The reversibility of the adsorption processes was investigated in order to check a potential decrease in the ability of NaB to protect birds against chronic aflatoxicoses. Adsorption processes were completely reversible for Trp, while almost irreversible for AFB₁. In spite of the high affinity of the NaB for Trp, probably due to the reversible character of Trp adsorption, no changes in the AFB₁ adsorption isotherm were observed when an excess of the amino acid was added to the adsorption medium. As a consequence of the preferential and irreversible AFB₁ adsorption and the reversible weak binding of Trp to the NaB, no changes in the aflatoxin sorption ability of the clay are expected to occur in the gastrointestinal tract of birds.