Novel strategies for degradation of aflatoxins in food and feed: A review

Pleurotus eryngii polysaccharides alleviate aflatoxin B1-induced liver inflammation in ducks involving in remodeling gut microbiota and regulating SCFAs transport via the gut-liver axis

Aflatoxin B1 (AFB1) is one of the most widespread contaminants in agricultural commodities. Pleurotus eryngii (PE) is widely used as a feed additive for its anti-inflammatory properties, and its major active substance is believed to be polysaccharides. This study aims to explore the underlying mechanism of dietary PE polysaccharides alleviating AFB1-induced toxicity in ducks. The major monosaccharide components of PE polysaccharides were identified as glucose, mannose, galactose, glucuronic acid, and fucose. The results showed that dietary PE polysaccharides could alleviate liver inflammation, alleviate intestinal barrier dysfunction, and change the imbalanced gut microbiota induced by AFB1 in ducks. However, PE polysaccharides failed to exert protective roles on the liver and intestine injury induced by AFB1 in antibiotic-treated ducks. The PE + AFB1-originated microbiota showed a positive effect on intestinal barrier and inflammation, the SCFAs transport via the gut-liver axis, and liver inflammation compared with the AFB1-originated microbiota in ducks. These findings provided a possible mechanism that PE polysaccharides alleviated AFB1-induced liver inflammation in ducks by remodeling gut microbiota, regulating microbiota-derived SCFAs transport via the gut-liver axis, and inhibiting inflammatory gene expressions in the liver, which may provide new insight for therapeutic methods against AFB1 exposure in animals.

Assessment of mycotoxin sequestration efficacy in Saccharomyces cerevisiae by-products cultured in wheat bran and whey protein medium

Mycotoxins are metabolic products of fungi found in feed for farm animals and pose a major threat to food safety due to their adverse health effects. The development of strategies to reduce their bioavailability is crucial. In this context, the cell wall components of Saccharomyces cerevisiae (YCW), especially β-D-glucans and Mannan-oligosaccharide, have been recognized as potent mycotoxin binders. The objective of this research was to develop a novel culture medium to increase the biomass yield of S. cerevisiae and optimize cell disruption by stepwise physical lysis and hydrolytic preconditioning. This process resulted in a yield of approximately 56% reducing saccharides and 28.54% protein. Subsequently, the β-glucan was extracted after cell wall sequestration. The isolated YCW and extracted β-glucan were characterized both individually and synergistically to evaluate their antibacterial properties and analyze their Fourier transform infrared (FTIR) spectra. In vitro evaluation of antibacterial activity revealed that a concentration greater than 250 μg/mL of YCW-β-glucan blend significantly inhibited the growth of Gram-negative bacteria. In addition, this blend showed good adsorption of various mycotoxins, including Aflatoxin B1, Ochratoxin A, and Zearalenone, the latter of which exhibited a remarkable adsorption rate of 80.85%. This study highlights the promising potential of a combination of YCW and β-glucan as a robust strategy to address the pervasive problem of mycotoxin contamination in feed.

Metabolites and degradation pathways of microbial detoxification of aflatoxins: a review

The degradation of aflatoxins using nonpathogenic microbes and their enzymes is emerging as a safe and economical alternative to chemical and physical methods for the detoxification of aflatoxins in food and feeds. Many bacteria and fungi have been identified as aflatoxin degraders. This review is focused on the chemical identification of microbial degradation products and their degradation pathways. The microbial degradations of aflatoxins are initiated by oxidation, hydroxylation, reduction, or elimination reactions mostly catalyzed by various enzymes belonging to the classes of laccase, reductases, and peroxidases. The resulting products with lesser chemical stability further undergo various reactions to form low molecular weight products. Studies on the chemical and biological nature of degraded products of aflatoxins are necessary to ensure the safety of the decontamination process. This review indicated the need for an integrated approach including decontamination studies using culture media and food matrices, proper identification and toxicity profiling of degraded products of aflatoxins, and interactions of microbes and the degradation products with food matrices for developing practical and effective microbial detoxification process.

A Magnetic Reduced Graphene Oxide Nanocomposite: Synthesis, Characterization, and Application for High-Efficiency Detoxification of Aflatoxin B1

(1) Background: Safety problems associated with aflatoxin B1 (AFB1) contamination have always been a major threat to human health. Removing AFB1 through adsorption is considered an attractive remediation technique. (2) Methods: To produce an adsorbent with a high AFB1 adsorption efficiency, a magnetic reduced graphene oxide composite (Fe3O4@rGO) was synthesized using one-step hydrothermal fabrication. Then, the adsorbent was characterized using a series of techniques, such as SEM, TEM, XRD, FT-IR, VSM, and nitrogen adsorption-desorption analysis. Finally, the effects of this nanocomposite on the nutritional components of treated foods, such as vegetable oil and peanut milk, were also examined. (3) Results: The optimal synthesis conditions for Fe3O4@rGO were determined to be 200 °C for 6 h. The synthesis temperature significantly affected the adsorption properties of the prepared material due to its effect on the layered structure of graphene and the loading of Fe3O4 nanoparticles. The results of various characterizations illustrated that the surface of Fe3O4@rGO had a two-dimensional layered nanostructure with many folds and that Fe3O4 nanoparticles were distributed uniformly on the surface of the composite material. Moreover, the results of isotherm, kinetic, and thermodynamic analyses indicated that the adsorption of AFB1 by Fe3O4@rGO conformed to the Langmuir model, with a maximum adsorption capacity of 82.64 mg·g-1; the rapid and efficient adsorption of AFB1 occurred mainly through chemical adsorption via a spontaneous endothermic process. When applied to treat vegetable oil and peanut milk, the prepared material minimized the loss of nutrients and thus preserved food quality. (4) Conclusions: The above findings reveal a promising adsorbent, Fe3O4@rGO, with favorable properties for AFB1 adsorption and potential for food safety applications.

Activate hydrogen peroxide for facile and efficient removal of aflatoxin B1 by magnetic Pd-chitosan/rice husk-hercynite biocomposite and its impact on the quality of edible oil

Due to the high heat and chemical stability of aflatoxin B1 (AFB1) with significant impacts on humans/animals and thus it needs to develop a practical and efficient approach for its removal. Herein, we fabricated a magnetic Pd-chitosan/glutaraldehyde/rice husk/hercynite (Pd@CRH-x) composite for efficient detoxification of AFB1. The Pd@CRH-x was obtained by a simple wet-impregnation procedure of CRH complexes followed by pyrolysis. The results confirmed that the unique structure of Pd@CRH-400 effectively improves dispersity, and mass transfer subsequently enhancing removal efficiency in batch conditions. Results indicate 94.30 % of AFB1 was efficiently degraded by 0.1 mg mL-1 Pd@CRH-400 with 4.0 mM H2O2 at wide pH ranges (3.0-10) at 60 min with a decomposition rate constant of 0.0467 min-1. Besides, by comparing the quality factors of edible oil (i.e., acid value, peroxide value, iodine value, moisture, volatile matters, anisidine value, and fatty acid composition), it was confirmed that there was no obvious influence on the physicochemical indicators of edible oil after removal/storage process. Subsequently, the systematic kinetic study and AFB1 degradation mechanism were presented. This study provides a new strategy for the efficient construction of controllable and dispersed Pd-based catalysts using CRH-x as a spatial support for alleviating the risk of toxic pollutants.

An integrated mycotoxin-mitigating agent can effectively mitigate the combined toxicity of AFB1, DON and OTA on the production performance, liver and oviduct health in broiler breeder hens

This study was to evaluate the efficacy of an integrated mycotoxin-mitigating agent in reducing the adverse effects of co-occurring dietary aflatoxin B1 deoxynivalenol and ochratoxin A on broiler breeder hens. 360 30-week-old Hubbard Efficiency Plus broiler breeder hens were allocated into four groups and received a basal diet (BD; Control), BD added 0.15 mg/kg aflatoxin B1+1.5 mg/kg deoxynivalenol+0.12 mg/kg ochratoxin A (Toxins), BD plus Toxins with 0.1% TOXO-XL (Toxins + XL1), and BD plus Toxins with 0.2% TOXO-XL (Toxins + XL2), respectively, for 8 weeks, and then received the same BD for another 4 weeks. Compared with control, mycotoxins decreased total egg weigh, egg laying rate, settable eggs rate, hatch of total eggs rate, egg quality, but increased feed/egg ratio and mortality rate, and impaired the liver and oviduct health during weeks 1-8 and(or) 9-12. It also increased PC and MDA concentrations, TUNEL-positive cells and IL-1β and IL-6 expression, and decreased T-AOC, GPX and CAT activities in liver and/or oviduct. Notably, most of these negative changes were mitigated by both dosages of TOXO-XL. Generally, 0.2% TOXO-XL displayed better mitigation effects than 0.1% TOXO-XL. Conclusively, these findings revealed that TOXO-XL could mitigate the combined mycotoxins-induced toxicity on the performance, liver and oviduct health, through the regulation of redox, immunity, and apoptosis in broiler breeder hens.

Chlorogenic Acid Alleviated AFB1-Induced Hepatotoxicity by Regulating Mitochondrial Function, Activating Nrf2/HO-1, and Inhibiting Noncanonical NF-κB Signaling Pathway

Aflatoxin B1 (AFB1), a kind of mycotoxin, imposes acute or chronic toxicity on humans and causes great public health concerns. Chlorogenic acid (CGA), a natural phenolic substance, shows a powerful antioxidant and anti-inflammatory effect. This study was conducted to investigate the effect and mechanism of CGA on alleviating cytotoxicity induced by AFB1 in L-02 cells. The results showed that CGA (160 μM) significantly recovered cell viability and cell membrane integrity in AFB1-treated (8 μM) cells. Furthermore, it was found that CGA reduced AFB1-induced oxidative injury by neutralizing reactive oxygen species (ROS) and activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. In addition, CGA showed anti-inflammatory effects as it suppressed the expression of inflammation-related genes (IL-6, IL-8, and TNF-α) and AFB1-induced noncanonical nuclear factor kappa-B (NF-κB) activation. Moreover, CGA mitigated AFB1-induced apoptosis by maintaining the mitochondrial membrane potential (MMP) and inhibiting mRNA expressions of Caspase-3, Caspase-8, Bax, and Bax/Bcl-2. These findings revealed a possible mechanism: CGA prevents AFB1-induced cytotoxicity by maintaining mitochondrial membrane potential, activating Nrf2/HO-1, and inhibiting the noncanonical NF-κB signaling pathway, which may provide a new direction for the application of CGA.

Simultaneous removal of four aflatoxins using magnetic nanobentonite as a green and fast sorbent: kinetic, thermodynamic, and isotherm investigation

In the study, an adsorptive removal strategy as a straightforward and fast procedure was developed to remove four aflatoxins, including aflatoxin B1 (AF-B1), aflatoxin B2 (AF-B2), aflatoxin G1 (AF-G1), and aflatoxin G2 (AF-G2). A simple and green sorbent consisting of two components (activated nanobentonite and Fe3O4 nanoparticles) was synthesized based on three steps using acidic treatment, ultrasonic procedure, and chemical precipitation method. The sorbent was characterized by several techniques such as FTIR, FESEM, TEM, XRD, and VSM to determine the sorbent structure and morphology. An experimental design based on a central composite design was utilized to optimize factors in the removal of AFs. The optimum values of the factors (pH, sorbent amount, shaking rate) were 6.8, 0.076 g, and 160 rpm, respectively. Three models, including pseudo-first-order, pseudo-second-order, and intra-particle diffusion models, were used to investigate the kinetics of the removal process. The removal of AFs using magnetic nanobentonite was fitted with the pseudo-second-order model better than other models with an equilibrium time lower than 30 min. The thermodynamic data show that the adsorption of AFs on the sorbent is a spontaneous and feasible process due to negative values of the Gibbs-free energy change (ΔG) at different temperatures. Two models (Langmuir and Freundlich models) were chosen to study the isotherm of the removal procedure, indicating that the Freundlich model describes the results better than the Langmuir model. The maximum adsorption capacity of the sorbent for removing AF-B1, AF-B2, AF-G1, and AF-G2 is 357.14, 400.0, 370.37, and 400.0 mg g-1, respectively. The sorbent reusability was also evaluated to study the sorbent's ability for the removal of AFs, indicating that the sorbent was used for 5 cycles without a significant reduction in the ability to remove AFs.

A comparative review on methods of detection and quantification of mycotoxins in solid food and feed: a focus on cereals and nuts

Many emerging factors and circumstances urge the need to develop and optimize the detection and quantification techniques of mycotoxins in solid food and feed. The diversity of mycotoxins, which have different properties and affinities, makes the standardization of the analytical procedures and the adoption of a single protocol that covers the attributes of all mycotoxins a tedious or even an impossible mission. Several modifications and improvements have been undergone in order to optimize the performance of these methods including the extraction solvents, the extraction methods, the clean-up procedures, and the analytical techniques. The techniques range from the rapid screening methods, which lack sensitivity and specificity such as TLC, to a spectrum of more advanced protocols, namely, ELISA, HPLC, and GC-MS and LC-MS/MS. This review aims at assessing the current studies related to these analytical techniques of mycotoxins in solid food and feed. It discusses and evaluates, through a critical approach, various sample treatment techniques, and provides an in-depth examination of different mycotoxin detection methods. Furthermore, it includes a comparison of their actual accuracy and a thorough analysis of the observed benefits and drawbacks.

Antifungal and elicitor activities of p-hydroxybenzoic acid for the control of aflatoxigenic Aspergillus flavus in kiwifruit

Aspergillus flavus not only reduces kiwifruit production but also synthesizes carcinogenic aflatoxins, resulting in a relevant threat to human health. p-Hydroxybenzoic acid (pHBA) is one of the most abundant phenolics in kiwifruit. In this study, pHBA was found to reduce A. flavus mycelial growth by blocking the fungal mitotic exit network (MEN) and cytokinesis and to inhibit the biosynthesis of aflatoxins B1 and B2. The application of pHBA promoted the accumulation of endogenous pHBA and induced oxidative stress in A. flavus-infected kiwifruit, resulting in an increase in H2O2 content and catalase (CAT) and superoxide dismutase (SOD) activities. Preventive and curative treatments with 5 mM pHBA reduced A. flavus advancement by 46.1% and 68.0%, respectively. Collectively, the antifungal and elicitor properties of pHBA were examined for the first time, revealing new insights into the role of pHBA in the defense response of kiwifruit against A. flavus infection.

Detoxification of mycotoxins in agricultural products by non-thermal physical technologies: a review of the past five years

Mycotoxins produced by Aspergillus spp., Penicillium spp. and Fusarium spp. with small molecular weight and thermal stability, are highly toxic and carcinogenic secondary metabolites. Mycotoxins have caused widespread concern regarding food safety internationally because of their adverse effects on the health of humans and animals, and the major economic losses they cause. There is an urgent need to find ways to reduce or eliminate the impact of mycotoxins in food and feed without introducing new safety issues, or reducing nutritional quality. Non-thermal physical technology is the basis for new techniques to degrade mycotoxins, with great potential for practical detoxification applications in the food industry. Compared with conventional thermal treatments, non-thermal physical detoxification technologies are easier to apply and effective, with less adverse impact on the nutritional value of agricultural products. The advantages, limitations and development prospects of these new detoxification technologies are discussed. Further studies are recommended to standardize the treatment conditions for each detoxification technology, evaluate the safety of the degradation products, and to combine different detoxification technologies to achieve synergistic effects. This will facilitate realization of the great potential of the new technologies and the development of practical applications.

Improvement of aflatoxin B1 degradation ability by Bacillus licheniformis CotA-laccase Q441A mutant

Aflatoxin B1 (AFB1) contamination seriously threatens nutritional safety and common health. Bacterial CotA-laccases have great potential to degrade AFB1 without redox mediators. However, CotA-laccases are limited because of the low catalytic activity as the spore-bound nature. The AFB1 degradation ability of CotA-laccase from Bacillus licheniformis ANSB821 has been reported by a previous study in our laboratory. In this study, a Q441A mutant was constructed to enhance the activity of CotA-laccase to degrade AFB1. After the site-directed mutation, the mutant Q441A showed a 1.73-fold higher catalytic efficiency (kcat/Km) towards AFB1 than the wild-type CotA-laccase did. The degradation rate of AFB1 by Q441A mutant was higher than that by wild-type CotA-laccase in the pH range from 5.0 to 9.0. In addition, the thermostability was improved after mutation. Based on the structure analysis of CotA-laccase, the higher catalytic efficiency of Q441A for AFB1 may be due to the smaller steric hindrance of Ala441 than Gln441. This is the first research to enhance the degradation efficiency of AFB1 by CotA-laccase with site-directed mutagenesis. In summary, the mutant Q441A will be a suitable candidate for highly effective detoxification of AFB1 in the future.

Ameliorative effects of camel milk and silymarin upon aflatoxin B1 induced hepatic injury in rats

Aflatoxin B1 (AFB1) poses a major risk to both human and animal health because it contaminates food, feed, and grains. These dangerous effects can be mitigated using natural components. The purpose of this study was to examine the ameliorative effects of camel milk and silymarin supplementation upon aflatoxin B1 induced hepatic injury in rats. This improvement was assessed by measuring leukocytic and deferential counts, serum biochemical parameters, and gene expression of Tumor Necrosis Factor (TNF-α), antioxidant gene (NAD(P)H quinone oxidoreductase 1 (NQO1)), and base excision repair genes (APE1 and OGG1) in the liver tissue, in addition to liver histopathology. Sixty mature males Wister white rats were used to perform the present study; the rats were distributed in six groups (ten rats/group). The control group (without any treatment) received saline by gavage. The camel milk group received 1 ml of camel milk/kg body weight. The silymarin group received 1 ml of silymarin suspension solution at a dose of 20 mg of silymarin/kg of b.wt. The aflatoxin group received an aflatoxin-contaminated diet at a dose of 1.4 mg of aflatoxin /kg of diet and received saline. The camel milk + aflatoxin group received the same previous oral doses of camel milk and an aflatoxin-contaminated diet at the same time. The silymarin + aflatoxin group received the same previous doses of silymarin orally and an aflatoxin-contaminated diet at the same time. The obtained data indicated the deleterious effect of aflatoxin B1 on the leukocytic count, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and the expression of the studied genes. However, these deleterious effects were mitigated by camel milk and silymarin supplementation. Thus, we could conclude that the ingestion of camel milk and silymarin mitigated the negative effects of AFB1 on the hematology, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and gene expression in the rat model.

Yeast polysaccharide mitigated oxidative injury in broilers induced by mixed mycotoxins via regulating intestinal mucosal oxidative stress and hepatic metabolic enzymes

This study was aimed to investigate the effects of yeast polysaccharides (YPS) on growth performance, intestinal health, and aflatoxin metabolism in livers of broilers fed diets naturally contaminated with mixed mycotoxins (MYCO). A total of 480 one-day-old Arbor Acre male broilers were randomly allocated into a 2 × 3 factorial arrangement of treatments (8 replicates with 10 birds per replicate) for 6 wk to assess the effects of 3 levels of YPS (0, 1, or 2 g/kg) on the broilers fed diets contaminated with or without MYCO (95 μg/kg aflatoxin B1, 1.5 mg/kg deoxynivalenol, and 490 μg/kg zearalenone). Results showed that mycotoxins contaminated diets led to significant increments in serum malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, mRNA expressions of TLR4 and 4EBP1 associated with oxidative stress, mRNA expressions of CYP1A1, CYP1A2, CYP2A6, and CYP3A4 associated with hepatic phase Ⅰ metabolizing enzymes, mRNA expressions of p53 associated with hepatic mitochondrial apoptosis, and AFB1 residues in the liver (P < 0.05); meanwhile dietary MYCO decreased the jejunal villus height (VH), villus height/crypt depth (VH/CD), the activity of serum total antioxidant capacity (T-AOC), mRNA expressions of jejunal HIF-1α, HMOX, and XDH associated with oxidative stress, mRNA expressions of jejunal CLDN1, ZO1, and ZO2, and mRNA expression of GST associated with hepatic phase Ⅱ metabolizing enzymes of broilers (P < 0.05). Notably, the adverse effects induced by MYCO on broilers were mitigated by supplementation with YPS. Dietary YPS supplementation reduced the concentrations of serum MDA and 8-OHdG, jejunal CD, mRNA expression of jejunal TLR2, and 4EBP1, hepatic CYP1A2, and p53, and the AFB1 residues in the liver (P < 0.05), and elevated the serum T-AOC and SOD, jejunal VH, and VH/CD, and mRNA expression of jejunal XDH, hepatic GST of broilers (P < 0.05). There were significant interactions between MYCO and YPS levels on the growth performance (BW, ADFI, ADG, and F/G) at d 1 to 21, d 22 to 42, and d 1 to 42, serum GSH-Px activity, and mRNA expression of jejunal CLDN2 and hepatic ras of broilers (P < 0.05). In contrast with MYCO group, the addition of YPS increased BW, ADFI, and ADG, the serum GSH-Px activity (14.31%-46.92%), mRNA levels of jejunal CLDN2 (94.39%-103.02%), decreased F/G, and mRNA levels of hepatic ras (57.83%-63.62%) of broilers (P < 0.05). In conclusion, dietary supplements with YPS protected broilers from mixed mycotoxins toxicities meanwhile keeping normal performance of broilers, presumably via reducing intestinal oxidative stress, protecting intestinal structural integrity, and improving hepatic metabolic enzymes to minimize the AFB1 residue in the liver and enhance the performance of broilers.

Current physical techniques for the degradation of aflatoxins in food and feed: Safety evaluation methods, degradation mechanisms and products

Aflatoxins are the most toxic natural mycotoxins discovered so far, posing a serious menace to the food safety and trading economy of the world, especially developing countries. How to effectively detoxify has persistently occupied a place on the list of "global hot-point" concerns. Among the developed detoxification methods, physical methods, as the authoritative techniques for aflatoxins degradation, could rapidly induce irreversible denaturation of aflatoxins. This review presents a brief overview of aflatoxins detection and degradation product structure identification methods. Four main safety evaluation methods for aflatoxins and degradation product toxicity assessment are highlighted combined with an update on research of aflatoxins decontamination in the last decade. Furthermore, the latest applications, degradation mechanisms and products of physical aflatoxin decontamination techniques including microwave heating, irradiation, pulsed light, cold plasma and ultrasound are discussed in detail. Regulatory issues related to "detoxification" are also explained. Finally, we put forward the challenges and future work in studying aflatoxin degradation based on the existing research. The purpose of supplying this information is to help researchers have a deeper understanding on the degradation of aflatoxins, break through the existing bottleneck, and further improve and innovate the detoxification methods of aflatoxins.

Endocrine Effect of Some Mycotoxins on Humans: A Clinical Review of the Ways to Mitigate the Action of Mycotoxins

Fungi such as Aspergillus spp. and Fusarium spp., which are commonly found in the environment, pose a serious global health problem. This study aims to present the results of epidemiological studies, including clinical cases, on the relationship between human exposure to some mycotoxins, especially zearalenone and aflatoxin, and the occurrence of reproductive disorders. In addition, examples of methods to reduce human exposure to mycotoxins are presented. In March 2023, various databases (PubMed, Google Scholar, EMBASE and Web of Science) were systematically searched using Google Chrome to identify studies evaluating the association between exposure to mycotoxins and the occurrence of complications related to impaired fertility or cancer incidence. The analysed data indicate that exposure to the evaluated mycotoxins is widespread and correlates strongly with precocious puberty, reduced fertility and increased cancer incidence in women and men worldwide. There is evidence to suggest that exposure to the Aspergillus mycotoxin aflatoxin (AF) during pregnancy can impair intrauterine foetal growth, promote neonatal jaundice and cause perinatal death and preterm birth. In contrast, exposure to the Fusarium mycotoxin zearalenone (ZEA) leads to precocious sexual development, infertility, the development of malformations and the development of breast cancer. Unfortunately, the development of methods (biological, chemical or physical) to completely eliminate exposure to mycotoxins has limited practical application. The threat to human health from mycotoxins is real and further research is needed to improve our knowledge and specific public health interventions.

Protective Effect of Long-Term Fermented Soybeans with Abundant Bacillus subtilis on Glucose and Bone Metabolism and Memory Function in Ovariectomized Rats: Modulation of the Gut Microbiota

We investigated the effects of different types of long-term fermented soybeans (traditionally made doenjang; TMD) on glucose and bone metabolism and memory function in ovariectomized (OVX) rats. The rats were categorized into six groups: Control, cooked unfermented soybeans (CSB), and four TMDs based on Bacillus subtilis (B. subtilis) and biogenic amine contents analyzed previously: high B. subtilis (HS) and high biogenic amines (HA; HSHA), low B. subtilis (LS) and HA (LSHA), HS and low biogenic amines (LA; HSLA), and LS and LA (LSLA). The rats in the CSB and TMD groups fed orally had a 4% high-fat diet for 12 weeks. Rats in the Control (OVX rats) and Normal-control (Sham-operated rats) groups did not consume CSB or TMD, although macronutrient contents were the same in all groups. Uterine weight and serum 17β-estradiol concentrations were much lower in the Control than the Normal-control group, but CSB and TMD intake did not alter them regardless of B. subtilis and biogenic amine contents. HOMA-IR, a measure of insulin resistance, decreased with TMD with high B. subtilis (HSLA and HSHA) compared to the Control group. In OGTT and IPGTT, serum glucose concentrations at each time point were higher in the Control than in the Normal-control, and HSLA and HSHA lowered them. Memory function was preserved with HSHA and HSLA administration. Bone mineral density decline measured by DEXA analysis was prevented in the HSHA and HSLA groups. Bone metabolism changes were associated with decreased osteoclastic activity, parathyroid hormone levels, and osteoclastic activity-related parameters. Micro-CT results demonstrated that TMD, especially HSLA and HSHA, preserved bone structure in OVX rats. TMD also modulated the fecal bacterial community, increasing Lactobacillus, Ligalactobacillus, and Bacillus. In conclusion, through gut microbiota modulation, TMD, particularly with high B. subtilis content, acts as a synbiotic to benefit glucose, bone, and memory function in OVX rats. Further research is needed to make specific recommendations for B. subtilis-rich TMD for menopausal women.

Hepatoprotective effects of chlorogenic acid on mice exposed to aflatoxin B1: Modulation of oxidative stress and inflammation

Aflatoxin B1 (AFB1) is widely distributed in crops and feeds, and ingestion of AFB1-contaminated crops is harmful to human/animal health. This study was designed to investigate hepatoprotective effects of chlorogenic acid (CGA), due to its excellent antioxidant and anti-inflammatory activities, on mice exposed to AFB1. Male Kunming mice were orally fed with CGA prior to daily AFB1 exposure for 18 consecutive days. The results showed that CGA treatment reduced the serum activity of aspartate aminotransferase, hepatic malondialdehyde content and pro-inflammatory cytokines synthesis, prevented histopathological changes of the liver, increased hepatic glutathione level, catalase activity and IL10 mRNA expression in mice subjected to AFB1. Taken together, CGA exerted the protective effect on AFB1-induced hepatic damage by modulating redox status and inflammation, suggesting that CGA may be a candidate compound for the treatment of aflatoxicosis.

Novel Strategies for the Biodegradation and Detoxification of Mycotoxins in Post-Harvest Grain

Mycotoxins are toxic secondary metabolites produced by filamentous fungi belonging, in particular, to the Aspergillus, Fusarium, and Penicillium genera [...].

Aflatoxin detection technologies: recent advances and future prospects

Aflatoxins have posed serious threat to food safety and human health. Therefore, it is important to detect aflatoxins in samples rapidly and accurately. In this review, various technologies to detect aflatoxins in food are discussed, including conventional ones such as thin-layer chromatography (TLC), high performance liquid chromatography (HPLC), enzyme linked immunosorbent assay (ELISA), colloidal gold immunochromatographic assay (GICA), radioimmunoassay (RIA), fluorescence spectroscopy (FS), as well as emerging ones (e.g., biosensors, molecular imprinting technology, surface plasmon resonance). Critical challenges of these technologies include high cost, complex processing procedures and long processing time, low stability, low repeatability, low accuracy, poor portability, and so on. Critical discussion is provided on the trade-off relationship between detection speed and detection accuracy, as well as the application scenario and sustainability of different technologies. Especially, the prospect of combining different technologies is discussed. Future research is necessary to develop more convenient, more accurate, faster, and cost-effective technologies to detect aflatoxins.

Natural mycotoxin contamination in dog food: A review on toxicity and detoxification methods

Nowadays, the companion animals (dogs or other pets) are considered as members of the family and have established strong emotional relationships with their owners. Dogs are long lived compared to food animals, so safety, adequacy, and efficacy of dog food is of great importance for their health. Cereals, cereal by-products as well as feedstuffs of plant origin are commonly employed food resources in dry food, yet are potential ingredients for mycotoxins contamination, so dogs are theoretically more vulnerable to exposure when consumed daily. Aflatoxins (AF), deoxynivalenol (DON), fumonisins (FUM), ochratoxin A (OTA), and zearalenone (ZEA) are the most frequent mycotoxins that might present in dog food and cause toxicity on the growth and metabolism of dogs. An understanding of toxicological effects and detoxification methods (physical, chemical, or biological approaches) of mycotoxins will help to improve commercial ped food quality, reduce harm and minimize exposure to dogs. Herein, we outline a description of mycotoxins detected in dog food, toxicity and clinical findings in dogs, as well as methods applied in mycotoxins detoxification. This review aims to provide a reference for future studies involved in the evaluation of the risk, preventative strategies, and clear criteria of mycotoxins for minimizing exposure, reducing harm, and preventing mycotoxicosis in dog.

Aflatoxin B1 Degradation by Ery4 Laccase: From In Vitro to Contaminated Corn

Aflatoxins (AFs) are toxic secondary metabolites produced by Aspergillus spp. and are found in food and feed as contaminants worldwide. Due to climate change, AFs occurrence is expected to increase also in western Europe. Therefore, to ensure food and feed safety, it is mandatory to develop green technologies for AFs reduction in contaminated matrices. With this regard, enzymatic degradation is an effective and environmentally friendly approach under mild operational conditions and with minor impact on the food and feed matrix. In this work, Ery4 laccase, acetosyringone, ascorbic acid, and dehydroascorbic acid were investigated in vitro, then applied in artificially contaminated corn for AFB₁ reduction. AFB₁ (0.1 µg/mL) was completely removed in vitro and reduced by 26% in corn. Several degradation products were detected in vitro by UHPLC-HRMS and likely corresponded to AFQ₁, epi-AFQ₁, AFB₁-diol, or AFB₁dialehyde, AFB_2a, and AFM₁. Protein content was not altered by the enzymatic treatment, while slightly higher levels of lipid peroxidation and H₂O₂ were detected. Although further studies are needed to improve AFB₁ reduction and reduce the impact of this treatment in corn, the results of this study are promising and suggest that Ery4 laccase can be effectively applied for the reduction in AFB₁ in corn.

Aflatoxin B1 Detoxification Potentials of Garlic, Ginger, Cardamom, Black Cumin, and Sautéing in Ground Spice Mix Red Pepper Products

The uses of natural plant origin bioactive compounds are emerging as a promising strategy to detoxify aflatoxin B1 (AFB1). This study aimed to explore the potential of cooking, phytochemicals content, and antioxidant activities derived from garlic, ginger, cardamom, and black cumin to detoxify AFB1 on spice mix red pepper powder (berbere) and sauté. The effectiveness of the samples was analyzed for AFB1 detoxification potential through standard methods for the examination of food and food additives. These major spices showed an AFB1 level below the detection limit. After cooking in hot water for 7 min at 85 ℃, the experimental and commercial spice mix red pepper showed the maximum AFB1 detoxification (62.13% and 65.95%, respectively). Thus, mixing major spices to produce a spice mix red pepper powder had a positive effect on AFB1 detoxification in raw and cooked spice mix red pepper samples. Total phenolic content, total flavonoid content, 2,2-diphenyl-1-picrylhydrazyl, ferric ion reducing antioxidant power, and ferrous ion chelating activity revealed good positive correlation with AFB1 detoxification at p < 0.05. The findings of this study could contribute to mitigation plans of AFB1 in spice-processing enterprises. Further study is required on the mechanism of AFB1 detoxification and safety of the detoxified products.

Superparamagnetic MnFe alloy composite derived from cross-bindered of chitosan/rice husk waste/iron aluminate spinel hercynite for rapid catalytic detoxification of aflatoxin B1: Structure, performance and synergistic mechanism

The contamination of foodstuffs with aflatoxins B1 (AFB1) as carcinogen/mutagens toxin produced by Aspergillus fungi that are a major threat to the economy, safe food supply, and human health. To, we present a facile wet-impregnation and co-participation strategies for the construction of a novel superparamagnetic MnFe biocomposite (MF@CRHHT), in which dual metal oxides MnFe were anchored in/on agricultural/forestry residues (chitosan/rice husk waste/hercynite hybrid nanoparticles) and applied for rapid AFB1 detoxification by destroying in a non-thermal/microbial way. Structure, and morphology were comprehensively characterized by various spectroscopic analyses. The AFB1 removal in PMS/MF@CRHHT system followed pseudo-first-order kinetics, and exhibited excellent efficiency (99.3 % in 20 min and 83.1 % in 5.0 min) over a broad pH range (5.0-10.0). Importantly, relationship between high efficiency and physical-chemical properties, and mechanistic insight reveals that the synergistic effect could be related to the formation MnFe bond in MF@CRHHT and then mutual electron transfer between them to enhanced electron density and generate reactive oxygen species. An AFB1 decontamination pathway proposed was based on the free radical quenching experiments and analysis of the degradation intermediates. Thus, the MF@CRHHT can be applied as an efficient, cost-effective, recoverable, environment-friendly and highly efficient biomass-based activator for remediate pollution.

Occurrence of aflatoxins in water and decontamination strategies: A review

Aflatoxins are highly carcinogenic metabolites produced by some Aspergillus species and are the most prevalent mycotoxins. Although aflatoxins are commonly synthesized during fungal colonization in preharvest maize, cereals, and nuts, they can be transported by rainfall to surface water and are a common toxin found in wastewater from some food industries. Here, the occurrence of aflatoxins in bodies of water is reviewed for the first time, along with the decontamination methods. Aflatoxins have been detected in surface, wastewater and drinking water, including tap and bottled water. The specific sources of water contamination remain unclear, which is an important gap that must be addressed in future research. Two main kinds of decontamination methods have been reported, including degradation and adsorption. The best degradation rates were observed using gamma and UV irradiations, oxidoreductases and ozone, while the best adsorption abilities were observed with minerals, polyvinyl alcohol, durian peel and activated carbon. Synthetic polymers could be used as membranes in pipes to remove aflatoxins in water flows. Although most decontamination methods were screened using AFB₁, the other commonly found aflatoxins were not used in the screenings. Overall, the occurrence of aflatoxins in water could be a significant emerging public health concern largely ignored by local and international legislation. Numerous advances have been reported for the decontamination of aflatoxins in water; however, there is still a long way to go to put them into practice.

The molecular mechanisms of alpha-lipoic acid on ameliorating aflatoxin B1-induced liver toxicity and physiological dysfunction in northern snakehead (Channa argus)

This research aimed to evaluate the protective mechanism of alpha-lipoic acid (α-LA) on the food-borne aflatoxin B₁ (AFB₁) exposure-induced liver toxicity and physiological dysfunction in the northern snakehead (Channa argus). 480 fish (9.24±0.01 g) were randomly assigned to four treatment groups and fed with four experimental diets for 56 d including the control group (CON), AFB₁ group (200 ppb AFB₁), 600 α-LA group (600 ppm α-LA+200 ppb AFB₁), and 900 α-LA group (900 ppm α-LA+200 ppb AFB₁). The results revealed that 600 and 900 ppm α-LA attenuated AFB₁-induced growth inhibition and immunosuppression in northern snakehead. 600 ppm α-LA significantly decreased the serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase levels, and AFB₁ bioaccumulation, and attenuated the changes of hepatic histopathological and ultrastructure induced by AFB₁. Moreover, 600 and 900 ppm α-LA significantly up-regulated phase I metabolism genes (cytochrome P450-1a, 1b, and 3a) mRNA expression, inhibited the levels of malondialdehyde, 8‑hydroxy-2 deoxyguanosine and reactive oxygen species in the liver. Notably, 600 ppm α-LA significantly up-regulated the expression levels of nuclear factor E2 related factor 2 and its related downstream antioxidant molecules (heme oxygenase 1 and NAD(P)H: quinone oxidoreductase 1, etc.), increased the phase II detoxification enzyme-related molecules (glutathione-S-transferase and glutathione), antioxidant parameters (catalase and superoxide dismutase, etc.), and the expressions of Nrf2 and Ho-1 protein in the presence of AFB₁ exposure. Furthermore, 600 and 900 ppm α-LA significantly reduced the characteristic indices of AFB₁-induced endoplasmic reticulum stress (glucose-regulated protein 78 and inositol requiring enzyme 1, etc.), apoptosis (caspase-3 and cytochrome c, etc.) and inflammation (nuclear factor kappa B and tumor necrosis factor α, etc.), while increased the B-cell lymphoma-2 and inhibitor of κBα in the liver after being exposed to AFB₁. To summarize, the above results indicate that dietary α-LA could modulate the Nrf2 signaling pathway to ameliorate AFB₁-induced growth inhibition, liver toxicity, and physiological dysfunction in northern snakehead. Although the concentration of α-LA increased to 900 ppm from 600 ppm, the protective effects of the 900 ppm α-LA do not show an advantage over the 600 ppm α-LA, and even show inferiority in some respects. So that the recommended concentration of α-LA is 600 ppm. The present study provides the theoretical foundation for developing α-LA as the prevention and treatment of AFB₁-induced liver toxicity in aquatic animals.

Efficient Inhibition of Aspergillus flavus to Reduce Aflatoxin Contamination on Peanuts over Ag-Loaded Titanium Dioxide

Peanuts are susceptible to aflatoxins produced by Aspergillus flavus. Exploring green, efficient, and economical ways to inhibit Aspergillus flavus is conducive to controlling aflatoxin contamination from the source. In this study, Ag-loaded titanium dioxide composites showed more than 90% inhibition rate against Aspergillus flavus under visible light irradiation for 15 min. More importantly, this method could also reduce the contaminated level of Aspergillus flavus to prevent aflatoxins production in peanuts, and the concentrations of aflatoxin B1, B2, and G2 were decreased by 96.02 ± 0.19%, 92.50 ± 0.45%, and 89.81 ± 0.52%, respectively. It was found that there are no obvious effects on peanut quality by evaluating the changes in acid value, peroxide value, and the content of fat, protein, polyphenols, and resveratrol after inhibition treatment. The inhibition mechanism was that these reactive species (•O2−, •OH−, h+, and e−) generated from photoreaction destroyed cell structures, then led to the reduced viability of Aspergillus flavus spores. This study provides useful information for constructing a green and efficient inhibition method for Aspergillus flavus on peanuts to control aflatoxin contamination, which is potentially applied in the field of food and agri-food preservation.

Characteristics of Aflatoxin B1 Degradation by Stenotrophomonas acidaminiphila and It's Combination with Black Soldier Fly Larvae

Aflatoxin B₁ (AFB₁) is a common mycotoxin contaminant in cereals that causes severe economic losses and serious risks to the health of humans and animals. In this paper, we investigated the characteristics of AFB₁ degradation by black soldier fly larvae (BSFL) combined with commensal intestinal microorganisms. Germ-free BSFL and non-sterile BSFL were reared on peanut meal spiked with AFB₁ for 10 days. The result showed that germ-free BSFL and non-sterile BSFL could achieve 31.71% and 88.72% AFB₁ degradation, respectively, which indicated the important role of larvae gut microbiota in AFB₁ degradation. Furthermore, twenty-five AFB₁-degrading bacteria were isolated from BSFL gut, and S. acidaminiphila A2 achieved the highest AFB₁ degradation, by 94%. When S. acidaminiphila A2 was re-inoculated to BSFL, the detrimental effect of AFB₁ on the growth performance of BSFL was alleviated, and complete AFB₁ degradation in peanut meal was obtained. In conclusion, the present study may provide a strategy to degrade AFB₁ in feedstuff through bioconversion with BSFL in combination with gut-originated AFB₁-degrading bacteria, while providing a sustainable insect protein and fat source to animals.

Sustainable Strategies to Counteract Mycotoxins Contamination and Cowpea Weevil in Chickpea Seeds during Post-Harvest

Mycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of deleterious organisms in foodstuff. Ozone treatment (O3, 500 ppb for 30, 60 or 90 min) and high nitrogen concentration (N2, 99% for 21 consecutive days) were tested in the post-harvest management of four batches of Cicer arietinum grains to control the presence of mycotoxigenic fungi and their secondary metabolites, as well as pest (i.e., Callosobruchus maculatus) infestation. At the end of the treatment, O3 significantly decreased the incidence of Penicillium spp. (by an average of -50%, independently to the time of exposure) and reduced the patulin and aflatoxins content after 30 min (-85 and -100%, respectively). High N2 concentrations remarkably reduced mycotoxins contamination (by an average of -94%) and induced pest mortality (at 100% after 5 days of exposure). These results confirm the promising potential of O3 and N2 in post-harvest conservation strategies, leading to further investigations to evaluate the effects on the qualitative characteristics of grains.

Advanced mycotoxin control and decontamination techniques in view of an increased aflatoxin risk in Europe due to climate change

Aflatoxins are toxic secondary metabolites produced by Aspergillus spp. found in staple food and feed commodities worldwide. Aflatoxins are carcinogenic, teratogenic, and mutagenic, and pose a serious threat to the health of both humans and animals. The global economy and trade are significantly affected as well. Various models and datasets related to aflatoxins in maize have been developed and used but have not yet been linked. The prevention of crop loss due to aflatoxin contamination is complex and challenging. Hence, the set-up of advanced decontamination is crucial to cope with the challenge of climate change, growing population, unstable political scenarios, and food security problems also in European countries. After harvest, decontamination methods can be applied during transport, storage, or processing, but their application for aflatoxin reduction is still limited. Therefore, this review aims to investigate the effects of environmental factors on aflatoxin production because of climate change and to critically discuss the present-day and novel decontamination techniques to unravel gaps and limitations to propose them as a tool to tackle an increased aflatoxin risk in Europe.

Novel Insights into Total Flavonoids of Rhizoma Drynariae against Meat Quality Deterioration Caused by Dietary Aflatoxin B1 Exposure in Chickens

Aflatoxin B1 (AFB1) is a group of highly toxic mycotoxins that are commonly found in human and animal foods and threaten animal and human food safety. Total flavonoids of Rhizoma Drynaria (TFRD), a traditional Chinese medicinal herb, exert multiple biological activities such as immunomodulatory, anti-inflammatory, and anti-oxidation effects. Here, a total of 160 healthy 21-day-old male broilers were randomly divided into four groups: the CON group, the TFRD group, the AFB1 group, and the AFB1 + TFRD group. The study found that AFB1 exposure altered the breast meat quality-related indicators, including meat sensory and physical indicators. Metabolomics analysis further showed that the change in meat quality was closely associated with significantly differential metabolites of breast muscle. Furthermore, spotlighted amino acid content contributes to changes in the secondary structure of the myofibrillar protein by Raman spectroscopy analysis, which was associated with the oxidative stress and inflammatory response in AFB1-exposed breast meat. Meanwhile, dietary 125 mg/kg TFRD supplementation could effectively restore the changes in breast meat quality. Taken together, these results by multi-technical analysis revealed that AFB1 exposure causes deterioration of chicken meat quality and that TFRD may be a potential herbal extract to antagonize mycotoxicity.

Epigallocatechin Gallate and Glutathione Attenuate Aflatoxin B1-Induced Acute Liver Injury in Ducklings via Mitochondria-Mediated Apoptosis and the Nrf2 Signalling Pathway

Aflatoxin B1 (AFB1) exists widely in feed and food with severe hazards, posing a serious threat to human and animal health. Epigallocatechin gallate (EGCG) and glutathione (GSH) have been reported as having anti-oxidative and other functions. The present study aimed to investigate the detoxification effect of EGCG and GSH alone or in combination on AFB1 exposure in ducklings. Fifty one-day-old male ducklings were randomly assigned into five experimental groups (n = 10): 1. Control (CTR); 2. 0.3 mg/kg BW AFB1 (AFB1); 3. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG (AFB1 + EGCG); 4. 0.3 mg/kg BW AFB1 + 30 mg/kg BW GSH (AFB1 + GSH); 5. 0.3 mg/kg BW AFB1 + 100 mg/kg BW EGCG + 30 mg/kg BW GSH (AFB1 + EGCG + GSH). The experiment lasted for seven days. Compared with the CTR group, AFB1 reduced growth performance, total serum protein and albumin content, increased serum enzyme activity (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase), and caused pathological damage to the ducklings' livers. AFB1 exposure increased malondialdehyde content and decreased superoxide dismutase, total antioxidant capacity, catalase, glutathione peroxidase activities, and glutathione content in the liver. EGCG and GSH alone or in combination mitigated these adverse effects. Meanwhile, EGCG and GSH attenuate apoptosis of hepatocytes, and regulated AFB1-induced changes in the abundance of genes contained in the Keap1/Nrf2 signalling and apoptotic pathways. Collectively, these results suggest that EGCG and GSH alleviate the hepatocyte injury induced by AFB1 by inhibiting oxidative stress and attenuating excessive mitochondria-mediated apoptosis.

Stability Evaluation of Aflatoxin B1 Solution Certified Reference Material via Ultra-High Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

Aflatoxin B₁ (AFB₁) solution certified reference materials (CRMs) have been widely utilized in the measurements of AFB₁ contaminations in foods and agricultural products. It is of great importance to evaluate the stability of AFB₁ solution CRMs in different matrices for their practical applications. In this study, the stability of AFB₁ solution CRM was investigated and its degradation products under various conditions were elucidated using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry for the first time. Exposure to high temperatures and UV light irradiation accelerated the degradation of AFB₁ solution significantly, and the degradation products were largely dependent on the solvents. Two degradation pathways were proposed based on the degradation products. The addition reaction, oxidation reaction, and modification of the methoxy group are the major processes involved in the degradation of the AFB₁ solution. The results of this study indicate that the property value of the acetonitrile solution of AFB₁ can be well retained when it is stored at temperatures lower than 60 °C, and the exposure to UV light irradiation is avoided.

Single, Subsequent, or Simultaneous Treatments to Mitigate Mycotoxins in Solid Foods and Feeds: A Critical Review

Mycotoxins in solid foods and feeds jeopardize the public health of humans and animals and cause food security issues. The inefficacy of most preventive measures to control the production of fungi in foods and feeds during the pre-harvest and post-harvest stages incited interest in the mitigation of these mycotoxins that can be conducted by the application of various chemical, physical, and/or biological treatments. These treatments are implemented separately or through a combination of two or more treatments simultaneously or subsequently. The reduction rates of the methods differ greatly, as do their effect on the organoleptic attributes, nutritional quality, and the environment. This critical review aims at summarizing the latest studies related to the mitigation of mycotoxins in solid foods and feeds. It discusses and evaluates the single and combined mycotoxin reduction treatments, compares their efficiency, elaborates on their advantages and disadvantages, and sheds light on the treated foods or feeds, as well as on their environmental impact.

Kinetics of microbial and photochemical degradation of aflatoxin B1 in a sandy loam and clay soil

In a 28-days experiment, we investigated the dissipation of aflatoxin B1 (AFB1) (0.5–500 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\upmu }\text {g}\,\text {kg}^{-1}$$\end{document}μgkg-1) by microbial (MD) and photodegradation (PD) in two contrasting soils (sandy loam and clay). Sterile incubation in darkness served as control (C). AFB1 was degraded in all scenarios according to simple first-order kinetics with 50% dissipation times of 20–32 (PD), 19–48 (MD), and 56–65 days (C), respectively. Dissipation rates were significantly lower (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {p}<0.001$$\end{document}p<0.001) in the clay soil than in the sandy loam soil, likely due to photoquenching and strong binding of AFB1 by clay minerals and humic substances. In the sandy loam, dissipation rate of MD decreased in function of initial AFB1 concentration, probably due to toxic effects on degrading microbes. In contrast, in the clay soil the dissipation rate increased with increasing concentration up to 250 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu \text {g}\,\text {kg}^{-1}$$\end{document}μgkg-1, followed by a sharp decrease at 500 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu \text {g}\,\text {kg}^{-1}$$\end{document}μgkg-1, indicating an effect of soil texture on the bioavailability of AFB1 to soil microbes. AFB2a was identified as a transformation product in all scenarios. These results confirm the function of soil for AFB1 degradation, which is modulated by abiotic and biotic processes, soil characteristics and initial AFB1 concentration.

The influence of ultraviolet radiation on aflatoxin producing Aspergillus species' isolated from Iranian rice

Cereal grains are a favorable habitat for aflatoxin- producing fungus to develop. the current investigation was carried out to evaluate the quantity and kind of contaminated imported grains and rice generated in the province of Shiraz, Iran. A total of 60 random rice samples were taken from paddy fields in October and November 2020. Aspergillus genera were detected using PCR. HPLC was used to determine the quantity and type of aflatoxin and mycotoxins in samples collected. Irradiation studies were carried out utilizing a collimated beam system with wavelengths ranging from 200 to 360 nm. The quality of rice was assessed using UV light therapy on some of the changed factors, such as amylose content, aroma, and brightness [P < 0.05]. Aspergillus genera were found in 33.3% [20 samples of 60] of rice samples after morphological and molecular analysis of the ITS gene. According to the sequencing experiment, 12 strains [60%] were identified as Aspergillus flavus, whereas 8 strains [40%] were identified as Aspergillus parasiticus. Ver-1 and afl-R genes were positive in 12/12 [100%] Aspergillus flavus and 87.5% in Aspergillus parasiticus. According to the HPLC findings, three Aspergillus parasiticus strains [37.5%] were able to create all four types of aflatoxins, and aflatoxins B1, B2, G1, G2 were produced by 16.6% of Aspergillus flavus strains. Aflatoxin-1 (AFG1) was lowered to 35.1, 48.2, 59.9, and 65.2%, significantly, at doses of 1.22, 2.44, 3.66, and 4.88 Jcm-2 [P < 0.01]. Furthermore, at doses of 1.22, 2.44, 3.66, and 4.88 Jcm-2, AFB2 and AFG2 was shown to be reduced by 13.1%, 11.7%, 30.3%, and 28.9%. [P < 0.05]. At a maximum dose of 4.88 Jcm-2, AFB1 was shown to be extremely susceptible to UV irradiation, with a > 70% decrease seen [P < 0.001]. Our findings imply that UV irradiation with lower energy and lower danger can help minimize aflatoxin contamination in food.

Antimicrobial action of phenolic acids combined with violet 405-nm light for disinfecting pathogenic and spoilage fungi

The aim of this study is to investigate the fungicidal spectrum of six phenolic-cinnamic and -benzoic acid derivatives using four fungi, Aspergillus niger, Cladosporium cladosporioides, Trichophyton mentagrophytes and Candida albicans, in a photocombination system with violet 405-nm light. This is the first study to examine the fungicidal mechanism involving oxidative damage using the conidium of A. niger, as well as an assessment of cellular function and chemical characteristics. The results of the screening assay indicated that ferulic acid (FA) and vanillic acid (VA), which possess 4-hydroxyl and 3-methoxy groups in their phenolic acid structures, produced synergistic activity with 405-nm light irradiation. FA and VA (5.0 mM) significantly decreased the viability of A. niger by 2.4 to 2.6-logs under 90-min irradiation. The synergistic effects were attenuated by the addition of the radical scavenger dimethyl sulfoxide. Generation of reactive oxygen species (ROS), such as hydrogen peroxide and hydroxyl radicals, were confirmed in the phenolic acid solutions tested after irradiation with colorimetric and electron spin resonance analyses. Adsorption of FA and VA to conidia was greater than other tested phenolic acids, and produced 1.55- and 1.85-fold elevation of intracellular ROS levels, as determined using an oxidant-sensitive probe with flow cytometry analysis. However, cell wall or membrane damage was not the main mechanism by which the combination-induced fungal death was mediated. Intracellular ATP was drastically diminished (5% of control levels) following combined treatment with FA and light exposure, even under a condition that produced negligible decreases in viability, thereby resulting in pronounced growth delay. These results suggest that the first stage in the photofungicidal mechanism is oxidative damage to mitochondria or the cellular catabolism system associated with ATP synthesis, which is a result of the photoreaction of phenolic acids adsorbed and internalized by conidia. This photo-technology in combination with food-grade phenolic acids can aid in developing alternative approaches for disinfection of pathogenic and spoilage fungi in the fields of agriculture, food processing and medical care.