Mycotoxins in botanicals and dried fruits: a review

Pixel-Level Recognition of Trace Mycotoxins in Red Ginseng Based on Hyperspectral Imaging Combined with 1DCNN-Residual-BiLSTM-Attention Model

Red ginseng is widely used in food and pharmaceuticals due to its significant nutritional value. However, during the processing and storage of red ginseng, it is susceptible to grow mold and produce mycotoxins, generating security issues. This study proposes a novel approach using hyperspectral imaging technology and a 1D-convolutional neural network-residual-bidirectional-long short-term memory attention mechanism (1DCNN-ResBiLSTM-Attention) for pixel-level mycotoxin recognition in red ginseng. The "Red Ginseng-Mycotoxin" (R-M) dataset is established, and optimal parameters for 1D-CNN, residual bidirectional long short-term memory (ResBiLSTM), and 1DCNN-ResBiLSTM-Attention models are determined. The models achieved testing accuracies of 98.75%, 99.03%, and 99.17%, respectively. To simulate real detection scenarios with potential interfering impurities during the sampling process, a "Red Ginseng-Mycotoxin-Interfering Impurities" (R-M-I) dataset was created. The testing accuracy of the 1DCNN-ResBiLSTM-Attention model reached 96.39%, and it successfully predicted pixel-wise classification for other unknown samples. This study introduces a novel method for real-time mycotoxin monitoring in traditional Chinese medicine, with important implications for the on-site quality control of herbal materials.

Practical Strategies to Reduce Ochratoxin A in Foods

Ochratoxin A (OTA), a potent nephrotoxin, is one of the most deleterious mycotoxins, with its prevalence in agricultural crops and their processed foods around the world. OTA is a major concern to food safety, as OTA exposure through dietary intake may lead to a significant level of accumulation in the body as a result of its long half-life (about 35 days). Its potent renal toxicity and high risk of exposure as well as the difficulty in controlling environmental factors OTA production has prompted the need for timely information on practical strategies for the food industry to effectively manage OTA contamination during food processing. The effects of various food processes, including both nonthermal and thermal methods, on the reduction in OTA were summarized in this review, with emphasis on the toxicity of residual OTA as well as its known and unknown degradation products. Since complete removal of OTA from foodstuffs is not feasible, additional strategies that may facilitate the reduction in OTA in food, such as adding baking soda and sugars, was also discussed, so that the industry may understand and apply practical measures to ensure the safety of its products destined for human consumption.

Occurrence of Mycotoxins in Dried Fruits Worldwide, with a Focus on Aflatoxins and Ochratoxin A: A Review

Dried fruits are popular and nutritious snacks consumed worldwide due to their long shelf life and concentrated nutrient content. However, fruits can be contaminated with various toxigenic fungal species during different stages, including cultivation, harvesting, processing, drying, and storage. Consequently, these products may contain high levels of mycotoxins. This risk is particularly pronounced in developed countries due to the impact of climate change. Several factors contribute to mycotoxin production, including the type of fruit, geographical location, climate conditions, harvest treatments, and storage management practices. The main mycotoxins in dried fruits are aflatoxins (AFs) and ochratoxin A (OTA), which can induce human health problems and economic losses. Mycotoxin contamination can vary significantly depending on the geographic origin of dried fruits (vine fruits, figs, dates, apricots, prunes, and mulberries). The aim of this review was to fill the knowledge gap by consolidating data from various regions to understand the global picture and identify regions with higher contamination risks. By consolidating research from various origins and stages of the supply chain, the review intends to shed light on potential contamination events during pre-harvest, drying, storage, and trading, while also highlighting the effects of storage conditions and climate change on mycotoxin contamination.

Contamination of herbal medicinal products in low-and-middle-income countries: A systematic review

The use of herbal medicinal products (HMPs) has grown significantly across low-and-middle-income countries (LMICs). Consequently, the safety of these products due to contamination is a significant public health concern. This systematic review aimed to determine the prevalence, types, and levels of contaminants in HMPs from LMICs. A search was performed in seven online databases, i.e., Africa journal online (AJOL), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Directory of Open Access Journals (DOAJ), Health Inter-Network Access to Research Initiative (HINARI), World Health Organization Global Index Medicus (WHO GIM), Scopus, and PubMed using appropriate search queries and reported as per the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) guidelines. Ninety-one peer-reviewed articles published from 1982 to 2021 from 28 different countries across four continents were included in the study. Although metals, microbial, mycotoxins, pesticides, and residual solvents were the reported contaminants in the 91 articles, metals (56.0%, 51/91), microbial (27.5%, 25/91), and mycotoxins (18.7%, 17/91) were the most predominant. About 16.4% (1236/7518) of the samples had their contaminant levels above the regulatory limits. Samples tested for microbial contaminants had the highest proportion (46.4%, 482/1039) of contaminants exceeding the regulatory limit, followed by mycotoxins (25.8%, 109/423) and metals (14.3%, 591/4128). The proportion of samples that had their average non-essential metal contaminant levels above the regulatory limit was (57.6%, 377/655), 18.3% (88/480), 10.7% (24/225), and 11.3% (29/257) for Pb, Cd, Hg, and As, respectively. The commonest bacteria species found were Escherichia coli (52.3%, 10/19) and Salmonella species (42.1%, 8/19). This review reported that almost 90% of Candida albicans and more than 80% of moulds exceeded the required regulatory limits. HMP consumption poses profound health implications to consumers and patients. Therefore, designing and/or implementing policies that effectively regulate HMPs to minimize the health hazards related to their consumption while improving the quality of life of persons living in LMICs are urgently needed.

Quantification and health risk assessment of ochratoxin A in dried fruit, spices, and coffee

Ochratoxin A (OTA) is a stable toxin produced by fungal strains of Aspergillus and Penicillium. It is commonly found in a variety of food products, including dried fruit, coffee, and spices, raising concerns about their safety. This study was aimed to quantify OTA levels in different food products using HPLC with fluorescence detection. The pre-treatment process was optimised by employing immunoaffinity columns with Tween 20 to effectively remove interfering substances. An analytical method was developed, validated, and applied for OTA analysis in dried fruit, spices, and coffee samples. The validation procedure included determining detection and quantification limits, linearity, precision, and accuracy, as per the criteria specified by AOAC International. The validated method was successfully applied for OTA analysis in the selected food samples. Furthermore, health risk assessment was conducted based on the average intake and body weight of the Korean population. From the results, concentrations of OTA in the samples were found to be very low and therefore concluded not to pose significant threats to consumer health.

Dry fruit image dataset for machine learning applications

Dry fruits are convenient and nutritious snacks that can provide numerous health benefits. They are packed with vitamins, minerals, and fibres, which can help improve overall health, lower cholesterol levels, and reduce the risk of heart disease. Due to their health benefits, dry fruits are an essential part of a healthy diet. In addition to health advantage, dry fruits have high commercial worth. The value of the global dry fruit market is estimated to be USD 6.2 billion in 2021 and USD 7.7 billion by 2028. The appearance of dry fruits is utilized for assessing their quality to a great extent, requiring neat, appropriately tagged, and high-quality images. Hence, this dataset is a valuable resource for the classification and recognition of dry fruits. With over 11500+ high-quality processed images representing 12 distinct classes, this dataset is a comprehensive collection of different varieties of dry fruits. The four dry fruits included in this dataset are Almonds, Cashew Nuts, Raisins, and Dried Figs (Anjeer), along with three subtypes of each. This makes it a total of 12 distinct classes of dry fruits, each with its unique features, shape, and size. The dataset will be useful for building machine learning models that can classify and recognize different types of dry fruits under different conditions, and can also be beneficial for dry fruit research, education, and medicinal purposes. Due to their nutritional value and health advantages, dry fruits have been consumed for a very long time. One of the best strategies to improve general health is to include dry fruits in the diet.

Probabilistic risk assessment of exposure to multiple mycotoxins in consumers of packaged and unpackaged spices in Iran

The current study assessed the risk posed to Iranian consumers by oral exposure to a mixture of ten mycotoxins in 138 packaged and unpackaged spices collected from the Iran market. Concentrations of mycotoxins in samples were quantified by liquid chromatography, tandem mass spectrometry with triple quadrupole, and ion trap. Probabilistic health risks of oral exposure to these mycotoxins for Iranians were assessed under percent tolerable daily intake (TDI) and cancer risk scenarios. Mean concentrations of mycotoxins in both packaged and unpackaged spice samples showed statistically significant variation among different spice samples. Based on a Monte Carlo simulation model, at the 50th, 80th, and 95th centiles, oral consumption of the analyzed samples poses no carcinogenic risk for exposure to aflatoxin. Moreover, in both packaged and unpackaged samples, while the percent TDIs for ochratoxin A, deoxynivalenol, zearalenone, patulin, fumonisin B1, and fumonisin B2 were below 1.0 at the 50th, 80th, and 95th centiles, the value was above 1.0 for aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 at each of these centiles.

Approaches for a more microbiologically and chemically safe dried fruit supply chain

Global production of dried fruits has increased significantly in the past decade. Both the increased consumer acceptance of nutritious packaged food and the broad use of dried fruits in products such as confectionery and bakery goods have fueled the dried fruit demand. Unfortunately, outbreaks and recalls due to contamination by pathogenic bacteria and viruses as well as the detection of mycotoxins highlight the need for optimizing current approaches, and evaluating and adopting newer interventions to protect the microbial and chemical safety of dried fruits. Drying processes alone are inadequate to control these hazards. Pre- and post-drying treatments serve as promising opportunities, with or without combination with the drying step, to achieve the goals of efficient hazard control.

Critical control point-based assessment and intervention of ochratoxin A risk in Angelicae Gigantis Radix production

Improperly practiced postharvest procedures can pose mycotoxin-related risks during medicinal herb production. As a health food material with pharmacological activities, Angelicae Gigantis Radix (AGR) has been extensively used in oriental medicine or functional foods. Compared with the official protocol, conventional practices were investigated for provisional critical control points (CCPs) in terms of ochratoxin A (OTA) contamination. Conventional practices include field-drying, which was associated with increased fungal exposure. Compared with conventional methods, the washing process in the official protocol was not advantageous for reducing OTA contamination in final products. Instead, drying was examined to assess the fungal growth risk during AGR production. To reduce the energy cost, product overload and shortened drying time could lead to failure in controlling fungal overgrowth and subsequent OTA production. In particular, inner parts of the load contained a higher OTA content than outer parts close to the heat outlet of the dryer. Improper thermal drying of loads allowed the growth of ochratoxigenic species during AGR production. Collectively, non-field-drying and optimally loaded thermal drying are easy preventive actions in key CCPs that need to be well maintained to attenuate any further microbial risk. These assessments provide insights into good practice-based mycotoxin risk management in producing herbal medicinal crops and new cost-efficient appropriate interventions for small-scale farms.

Multi-mycotoxin analysis method using liquid chromatography with tandem mass spectrometry and fluorescence detection in Indian medicinal herbs: Development and validation

While medicinal plants are in high demand worldwide for their therapeutic properties, they can constitute a health concern to consumers when contaminated with mycotoxins. The unavailability of standardised methods for multiclass mycotoxin analysis to assess health risks has thus been realised. This study reports a simple, robust and precise method to estimate nine regulated mycotoxins in a range of Indian medicinal plant matrices including giloy (Tinospora cordifolia), ashwagandha (Withania somnifera), safed musli (Chlorophytum borivilianum), satavari (Asparagus racemosus) and tulsi (Ocimum sanctum). The sample preparation method involved extraction of homogenised matrices (12.5 g) using methanol:water (8:2, 100 mL) followed by cleanup through a multi-mycotoxin immunoaffinity column (IAC), which significantly reduced matrix interferences. The method was initially developed and validated using liquid chromatography tandem mass spectrometry (LC-MS/MS) for the simultaneous analysis of aflatoxins (B₁, B₂, G₁, G₂), ochratoxin A, zearalenone, deoxynivalenol, T-2 and HT-2 toxin. Later, it was validated using LC-fluorescence (LC-FLD) for aflatoxins, ochratoxin A and zearalenone. The optimised sample preparation protocol and analytical method provided acceptable results. Compared to LC-FLD, it was possible to attain a lower limit of quantification (LOQ) with LC-MS/MS for all the tested analytes except aflatoxins. However, LOQs of both instruments were lower than the maximum limits (MLs), with recoveries ranging between 71 and 110% and precision (RSD) of ≤10% across matrices. Despite matrix-induced signal suppressions in LC-MS/MS analysis, the matrix-matched calibrations corrected all recoveries. Considering its accuracy, reliability, robustness and time-effectiveness, this method is recommended for regulatory testing purposes.

Mycotoxins in raw materials, beverages and supplements of botanicals: A review of occurrence, risk assessment and analytical methodologies

Over recent years, consumer interest in natural products, such as botanicals has increased considerably. One of the factors affecting their quality is the presence of mycotoxins. This review focuses on exploring the mycotoxin occurrence in botanicals (raw material and ready-to-eat forms such as infusions or tablets) and the risk assessment due to their ingestion. Aflatoxins, Ochratoxin A, and Fumonisins are the most commonly studied mycotoxins and data in the literature report levels ranging from traces to 1000 μg/kg in raw materials. In general, the highest contents observed in raw materials decreased to unconcerning levels after the preparation of the infusions, reaching values that generally do not exceed 100 μg/L. Regarding botanical dietary supplements, the levels observed were lower than those reported for other matrices, although higher levels (of up to 1000 μg/kg) have been reported in some cases. Risk assessment studies in botanicals revealed a higher risk when they are consumed as tablets compared to infusions. Analytical methodologies implied in mycotoxin determination have also been contemplated. In this sense, liquid chromatography coupled to fluorescence detection has been the most frequently employed analytical technique, although in recent years tandem mass spectrometry has been widely used.

Determination of Mycotoxins in Dried Fruits Using LC-MS/MS-A Sample Homogeneity, Troubleshooting and Confirmation of Identity Study

To monitor co-exposure to toxic mycotoxins in dried fruits, it is advantageous to simultaneously determine multiple mycotoxins using a single extraction and liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis. In this study, we applied a stable isotope dilution and LC-MS/MS method to multi-mycotoxin analysis in dried fruits, selecting raisins, plums, figs, and cranberries for matrix extension. Samples were prepared using cryogenic grinding, followed by the fortification of carbon-13 (13C) uniformly labeled internal standards for twelve mycotoxins, and extraction using 50% acetonitrile. Homogeneity of prepared samples, defined as particle size Dv90 < 850 µm for the tested matrices, was characterized using a laser diffraction particle size analyzer, and reached using cryogenic grinding procedures. The majority of recoveries in the four matrices for aflatoxins and ochratoxin A spiked at 1−100 ng/g; fumonisins, T-2 toxin, HT-2 toxin, and zearalenone spiked at 10−1000 ng/g, ranged from 80 to 120% with relative standard deviations (RSDs) of <20%. Deoxynivalenol was not detected at 10 and 100 ng/g in plums, and additional troubleshooting procedures using liquid-liquid extraction (LLE), solid phase extraction (SPE), and elution gradient were evaluated to improve the detectability of the mycotoxin. Furthermore, we confirmed the identity of detected mycotoxins, ochratoxin A and deoxynivalenol, in incurred samples using enhanced product ion scans and spectral library matching.

Microbial Contamination and Occurrence of Aflatoxins in Processed Baobab Products in Kenya

Baobab fruit demand has been on the rise in the recent past, and in an attempt to match the demand, farmers and middlemen are forced to harvest immature fruits which are not fully dried. To ensure an acceptable moisture content, baobab fruits are subjected to solar drying, which is a slow process and often carried out in open and unhygienic conditions raising safety concerns. This study was conducted to investigate the microbial and aflatoxin contamination levels in ready-to-eat baobab products from selected formal and informal processors in specific counties of Kenya. Selected processed baobab products were sampled randomly from formal and informal processors and analyzed for the total aerobic count, Enterobacteriaceae, yeast and molds, ergosterol, aflatoxins, moisture, and water activity. The moisture and water activity of baobab pulp and candies from formal processors ranged between 7.73% and 15.06% and 0.532 and 0.740 compared to those from informal processors which ranged from 10.50% to 23.47% and 0.532 to 0.751, respectively. In this study, baobab pulp from formal processors had significantly ( $p=0.0008$ , 0.0006) lower Enterobacteriaceae and yeast and molds loads ( $0.7\pm 0.29$ and $3.1\pm 0.38$ log 10 CFU/g, respectively) than pulp from informal processors ( $3.1\pm 0.70$ and $5.3\pm 0.11$ log 10 CFU/g, respectively). Similarly, the Enterobacteriaceae counts of candies from formal processors (nondetectable) were considerably lower ( $p=0.015$ ) than those from informal processors ( $1.8\pm 0.56$ log 10 CFU/g). The ergosterol content in these baobab product samples ranged between 0.46 and 1.92 mg/100 g while the aflatoxin content ranged between 3.93 and $11.09\times 103\mu \text{g}/\text{kg}$ , respectively. Fungal and aflatoxin contamination was detected in 25% and 5% of pulp from formal and informal processors, respectively, and in 5% of candies from informal processors. Microbial contamination in processed baobab products shows an unhygienic processing environment while the fungal and aflatoxin contamination may indicate poor postharvest handling, transport, and storage conditions of baobab fruits along the baobab value chain.

Mycotoxins’ Toxicological Mechanisms Involving Humans, Livestock and Their Associated Health Concerns: A Review

Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.

Investigating the Opposing Effect of Two Different Green Tea Supplements on Oxidative Stress, Mitochondrial Function and Cell Viability in HepG2 Cells

Green tea extract (GTE) improves exercise outcomes and reduces obesity. However, case studies indicate contradictory physiology regarding liver function and toxicity. We studied the effect of two different decaffeinated GTE (dGTE) products, from a non-commercial (dGTE1) and commercial (dGTE2) supplier, on hepatocyte function using the human cell model, HepG2. dGTE1 was protective against hydrogen peroxide (H₂O₂)-induced apoptosis and cell death by attenuating oxidative stress pathways. Conversely, dGTE2 increased cellular and mitochondrial oxidative stress and apoptosis. A bioavailability study with dGTE showed the major catechin in GTE, EGCG, reached 0.263 µg·ml^-1. In vitro, at this concentration, EGCG mimicked the protective effect of dGTE1. GC/MS analysis identified steric acid and higher levels of palmitic acid in dGTE2 versus dGTE1 supplements. We demonstrate the significant biological differences between two GTE supplements which may have potential implications for manufacturers and consumers to be aware of the biological effects of supplementation.

Effect of Temperature during Drying and Storage of Dried Figs on Growth, Gene Expression and Aflatoxin Production

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.

Fungal natural products galaxy: Biochemistry and molecular genetics toward blockbuster drugs discovery

Secondary metabolites synthesized by fungi have become a precious source of inspiration for the design of novel drugs. Indeed, fungi are prolific producers of fascinating, diverse, structurally complex, and low-molecular-mass natural products with high therapeutic leads, such as novel antimicrobial compounds, anticancer compounds, immunosuppressive agents, among others. Given that these microorganisms possess the extraordinary capacity to secrete diverse chemical scaffolds, they have been highly exploited by the giant pharma companies to generate small molecules. This has been made possible because the isolation of metabolites from fungal natural sources is feasible and surpasses the organic synthesis of compounds, which otherwise remains a significant bottleneck in the drug discovery process. Here in this comprehensive review, we have discussed recent studies on different fungi (pathogenic, non-pathogenic, commensal, and endophytic/symbiotic) from different habitats (terrestrial and marines), the specialized metabolites they biosynthesize, and the drugs derived from these specialized metabolites. Moreover, we have unveiled the logic behind the biosynthesis of vital chemical scaffolds, such as NRPS, PKS, PKS-NRPS hybrid, RiPPS, terpenoids, indole alkaloids, and their genetic mechanisms. Besides, we have provided a glimpse of the concept behind mycotoxins, virulence factor, and host immune response based on fungal infections.

Co-occurrence of mycotoxins, aflatoxin biosynthetic precursors, and Aspergillus metabolites in garlic (Allium sativum L) marketed in Zaria, Nigeria

Multi-mycotoxin analysis of 72 samples of garlic bulbs sold in Zaria markets was carried out using a liquid chromatography-mass spectrometry (LC-MS/MS) method. The results indicated the presence of seven major mycotoxins, including aflatoxin B1 (AFB₁), ochratoxin A (OTA), and the fumonisins B₁, B₂, B₃, B₄, and B₆, at different levels of contamination. AFB1 and OTA were detected in 1 of the 72 samples (1.4%) with median concentrations of 5.48 and 12.3 µg/kg, respectively. FB₁ and FB₂ were detected in 77% and 100% of the analysed samples, with median concentrations of 401 µg/kg and 491 µg/kg, respectively. The observed levels of AFB₁, OTA, FB₁, and FB₂ were above the EU maximum limit in herbal products. Sterigmatocystin (STC), an AFB₁ biosynthetic precursor, was present in all tested samples. The contamination level of mycotoxins and Aspergillus metabolites of marketed garlic in the study area is of public health concern.

Quality of Dietary Supplements Containing Plant-Derived Ingredients Reconsidered by Microbiological Approach

Dietary supplements cover a wide range of products, the most popular are those containing plant-based ingredients. Supplements are consumed by consumers of all ages as well as by both healthy and sick people. The lack of unified regulation in this sector increases the probability that supplements are poor chemical and microbiological quality and can be dangerous for patients. The aim of this paper is to highlight selected issues associated with the microbiological quality of dietary supplements containing plant materials. We focus on the most recent reports referring to bacterial and fungal contaminations as well as the presence of mycotoxins. Dietary supplements containing plant ingredients commonly show a variety of microbial contaminants, which might be crucial for consumer safety. They often contain microorganisms potentially pathogenic to humans. Metabolites produced by microorganisms may pose a threat to the health of consumers. Because of that, in this review, we emphasize the risk that may be associated with the lack of appropriate studies of the quality of the supplements.

A Review: Sample Preparation and Chromatographic Technologies for Detection of Aflatoxins in Foods

As a class of mycotoxins with regulatory and public health significance, aflatoxins (e.g., aflatoxin B1, B2, G1 and G2) have attracted unparalleled attention from government, academia and industry due to their chronic and acute toxicity. Aflatoxins are secondary metabolites of various Aspergillus species, which are ubiquitous in the environment and can grow on a variety of crops whereby accumulation is impacted by climate influences. Consumption of foods and feeds contaminated by aflatoxins are hazardous to human and animal health, hence the detection and quantification of aflatoxins in foods and feeds is a priority from the viewpoint of food safety. Since the first purification and identification of aflatoxins from feeds in the 1960s, there have been continuous efforts to develop sensitive and rapid methods for the determination of aflatoxins. This review aims to provide a comprehensive overview on advances in aflatoxins analysis and highlights the importance of sample pretreatments, homogenization and various cleanup strategies used in the determination of aflatoxins. The use of liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE) and immunoaffinity column clean-up (IAC) and dilute and shoot for enhancing extraction efficiency and clean-up are discussed. Furthermore, the analytical techniques such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), capillary electrophoresis (CE) and thin-layer chromatography (TLC) are compared in terms of identification, quantitation and throughput. Lastly, with the emergence of new techniques, the review culminates with prospects of promising technologies for aflatoxin analysis in the foreseeable future.

Microbiological Detoxification of Mycotoxins: Focus on Mechanisms and Advances

Some fungal species of the genera Aspergillus, Penicillium, and Fusarium secretes toxic metabolites known as mycotoxins, have become a global concern that is toxic to different species of animals and humans. Biological mycotoxins detoxification has been studied by researchers around the world as a new strategy for mycotoxin removal. Bacteria, fungi, yeast, molds, and protozoa are the main living organisms appropriate for the mycotoxin detoxification. Enzymatic and degradation sorptions are the main mechanisms involved in microbiological detoxification of mycotoxins. Regardless of the method used, proper management tools that consist of before-harvest prevention and after-harvest detoxification are required. Here, in this review, we focus on the microbiological detoxification and mechanisms involved in the decontamination of mycotoxins.

Vaccinium macrocarpon (Cranberry)-Based Dietary Supplements: Variation in Mass Uniformity, Proanthocyanidin Dosage and Anthocyanin Profile Demonstrates Quality Control Standard Needed

Vaccinium macrocarpon (syn. American Cranberry) is employed in dietary supplements (DS) with the aim to improve urinary tract well-being. This property is linked to the antiadhesion-activity of proanthocyanidins (PACs) against uropathogenic-bacteria. However, the current European legislation has been criticized for being weak and ineffective. Indeed, recent scientific works report mislabeled, contaminated, and adulterated supplements containing dangerous or unknown compounds, or sold at toxic doses. In this work, we analysed 24 DS that claim to contain cranberry, and to have a specific dosage of PACs. Our tests included the control of the good manufacturing practice according to the European Pharmacopoeia, and the verification of the claimed dosage of PACs. Moreover, in order to confirm the real presence of cranberry in DS, chemical fingerprinting via HPLC-UV/Vis-MS/MS was employed. Our results showed that 17 DS did not comply with the uniformity test of dosage forms, and only five contained cranberry. Finally, 16 DS claimed an incorrect amount of PACs. These data suggest that several cranberry-based DS are present in the European market with insufficient quality controls. Considering that often DS are self-prescribed by consumer relying on their claim, the data obtained in this work should encourage more controls and stricter rules.

Dried Fruit Intake and Cancer: A Systematic Review of Observational Studies

Insufficient intake of total fruits and vegetables is linked to an increased cancer risk, but the relation is not understood for dried fruits. Dried fruits are generally perceived, by both consumers and researchers, as a less attractive but shelf-stable equivalent to fresh fruits and constitute a small but significant proportion of modern diets. Chemical compositions of raw and dried fruits, however, may differ substantially. Several clinical and laboratory intervention studies have reported the protective effects of dehydrated fruits against the progression of some cancers and the modulating effects of dried fruits on common cancer risk factors. In this systematic review, we identified, summarized, and critically evaluated 9 prospective cohort and 7 case-control studies that examined the relations between traditional dried fruit (raisins, prunes, dates) consumption and cancer risk in humans. Prospective cohort studies determined that significant reductions in relative risk of precancerous colorectal polyps, incidence of prostate cancer, or mortality from pancreatic cancer, by, respectively, 24%, 49%, and 65%, were associated with 3-5 or more servings of dried fruits per week. Selected case-control studies revealed inverse associations between dried fruit intake and risk of cancer as well. The reported associations were comparable to or stronger than those observed for total or raw fruits. Although the small number and high heterogeneity impede meta-analysis of these studies, we conclude that currently available data provide some initial evidence that consumption of dried fruits may be associated with a lower cancer incidence or mortality in populations. The data suggest that higher intake of raisins and other dried fruits may be important in the prevention of cancers of the digestive system. Because only a limited number of health outcome and dried fruit intake relations have been evaluated in prospective studies to date, reanalyzing existing high-quality epidemiological data may expand the knowledge base.

Predominant Mycotoxins, Pathogenesis, Control Measures, and Detection Methods in Fermented Pastes

Fermented pastes are some of the most popular traditional products in China. Many studies reported a strong possibility that fermented pastes promote exposure to mycotoxins, including aflatoxins, ochratoxins, and cereulide, which were proven to be carcinogenic and neurotoxic to humans. The primary mechanism of pathogenicity is by inhibiting protein synthesis and inducing oxidative stress using cytochrome P450 (CYP) enzymes. The level of mycotoxin production is dependent on the pre-harvest or post-harvest stage. It is possible to implement methods to control mycotoxins by using appropriate antagonistic microorganisms, such as Aspergillus niger, Lactobacillus plantarum, and Saccharomyces cerevisiae isolated from ordinary foods. Also, drying products as soon as possible to avoid condensation or moisture absorption in order to reduce the water activity to lower than 0.82 during storage is also effective. Furthermore, organic acid treatment during the soaking process reduces toxins by more than 90%. Some novel detection technologies based on magnetic adsorption, aptamer probes, and molecular-based methods were applied to rapidly and accurately detect mycotoxins in fermented pastes.

Effect of pretreatments on mycotoxin profiles and levels in dried figs

The aim of this explorative study was to investigate how effective drying preservation methods are in reducing mycotoxin content in figs. Dried autochthonous varieties of white and dark figs (Petrovača Bijela and Šaraguja, respectively) were analysed for mycotoxins using an LC-MS/MS "dilute and shoot" method capable of determining 295 fungal and bacterial secondary metabolites. Before drying in a cabinet dryer the figs were preserved with 0.5 % citric acid solution or 0.5 % ascorbic acid solution or 0.3 % L-cysteine solution or 0.2 % chestnut extract solution or 0.15 % Echinacea extract solution by immersion. We found nine metabolites: aflatoxin B1 (AFB1), ochratoxin A, ochratoxin alpha, kojic acid, emodin, altenuene, alternariol methyl ether, brevianamide F, and tryptophol. The most efficient preserver was L-cysteine (15 % reduction), while ascorbic acid favoured mycotoxin production (158 % increase). However, all pretreatment solutions reduced AFB1, which is a major fig contaminant.

Mycotoxins in herbal teas marketed in Latvia and dietary exposure assessment

The occurrence of 12 mycotoxins has been analysed by liquid chromatography - time of flight mass spectrometry in the batch of 60 herbal teas purchased from drugstores in Latvia. Among the dry tea samples, 90% were positive for one to eight mycotoxins. Enniatin B and deoxynivalenol (DON) were the most frequently detected mycotoxins in 55% and 45% of the samples, respectively. DON reached the highest level, from 129 µg kg^-1 in herbal blend to 5,463 µg kg^-1 in wormwood tea. Ochratoxin A (OTA) and aflatoxin B₁ (AFB₁) were found in 10% and 20% of the samples at the concentrations ranged between 2.99-30.3 µg kg^-1 and 3.40-23.7 µg kg^-1. Studies of the tea infusion process indicated that 32-100% of DON and zearalenone present in dry teas were extracted into the infusions. Dietary exposure assessment was performed, using the determined mycotoxin levels and the available consumption data.

Transcriptional Regulation of Aflatoxin Biosynthesis and Conidiation in Aspergillus flavus by Wickerhamomyces anomalus WRL-076 for Reduction of Aflatoxin Contamination

Aspergillus flavus is a ubiquitous saprophytic fungus found in soils across the world. The fungus is the major producer of aflatoxin (AF) B₁, which is toxic and a potent carcinogen to humans. Aflatoxin B₁ (AFB₁) is often detected in agricultural crops such as corn, peanut, almond, and pistachio. It is a serious and recurrent problem and causes substantial economic losses. Wickerhamomyces anomalus WRL-076 was identified as an effective biocontrol yeast against A. flavus. In this study, the associated molecular mechanisms of biocontrol were investigated. We found that the expression levels of eight genes, aflR, aflJ, norA, omtA, omtB, pksA, vbs, and ver-1 in the aflatoxin biosynthetic pathway cluster were suppressed. The decreases ranged from several to 10,000 fold in fungal samples co-cultured with W. anomalus. Expression levels of conidiation regulatory genes brlA, abaA, and wetA as well as sclerotial regulatory gene (sclR) were all down regulated. Consistent with the decreased gene expression levels, aflatoxin concentrations in cultural medium were reduced to barely detectable. Furthermore, fungal biomass and conidial number were significantly reduced by 60% and more than 95%, respectively. The results validate the biocontrol efficacy of W. anomalus WRL-076 observed in the field experiments.

Mycotoxin Contamination of Beverages Obtained from Tropical Crops

This review is mainly centered on beverages obtained from tropical crops, including tea, nut milk, coffee, cocoa, and those prepared from fruits. After considering the epidemiological data found on the matrices above, the focus was given to recent methodological approaches to assess the most relevant mycotoxins. Aspects such as singularities among the mycotoxin and the beverage in which their were found, and the economic effects and repercussions that the mycotoxin-tainted ingredients have on the beverage industry were pointed out. Finally, the burden of their consumption through beverages, including risk and health effects on humans, was addressed as well.

Isolation and Evaluation of New Antagonist Bacillus Strains for the Control of Pathogenic and Mycotoxigenic Fungi of Fig Orchards

Bacillus is an antagonistic bacteria that shows high effectiveness against different phytopathogenic fungi and produces various lytic enzymes, such as chitosanase, chitinase, protease, and gluconase. The aim of this study is to determine Bacillus spp. for lytic enzyme production and to evaluate the antifungal effects of the selected strains for biocontrol of mycotoxigenic and phytopathogenic fungi. A total of 92 endospore-forming bacterial isolates from the 24 fig orchard soil samples were screened for chitosanase production, and six best chitosanolytic isolates were selected to determine chitinase, protease, and N-acetyl-β-hexosaminidase activity and molecularly identified. The antagonistic activities of six Bacillus strains against Aspergillus niger EGE-K-213, Aspergillus foetidus EGE-K-211, Aspergillus ochraceus EGE-K-217, and Fusarium solani KCTC 6328 were evaluated. Fungal spore germination inhibition and biomass inhibition activities were also measured against A. niger EGE-K-213. The results demonstrated that Bacillus mojavensis EGE-B-5.2i and Bacillus thuringiensis EGE-B-14.1i were more efficient antifungal agents against A. niger EGE-K-213. B. mojavensis EGE-B-5.2i has shown maximum inhibition of the biomass (30.4%), and B. thuringiensis EGE-B-14.1i has shown maximum inhibition of spore germination (33.1%) at 12 h. This is the first study reporting the potential of antagonist Bacillus strains as biocontrol agents against mycotoxigenic fungi of fig orchads.

Development of a droplet digital PCR assay for population analysis of aflatoxigenic and atoxigenic Aspergillus flavus mixtures in soil

Aflatoxin B₁ is a potent hepatotoxin and carcinogen that poses a serious safety hazard to both humans and animals. Aspergillus flavus is the most common aflatoxin-producing species on corn, cotton, peanuts, and tree nuts. Application of atoxigenic strains to compete against aflatoxigenic strains of A. flavus has emerged as one of the most practical strategies for ameliorating aflatoxin contamination in food. Genes directly involved in aflatoxin biosynthesis are clustered on an 82-kb region of the genome. Three atoxigenic strains (CA12, M34, and AF123) were each paired with each of four aflatoxigenic strains (CA28, CA42, CA90, and M52), inoculated into soil and incubated at 28 °C for 2 weeks and 1 month. TaqMan probes, omtA-FAM, and norA-HEX were designed for developing a droplet digital PCR (ddPCR) assay to analyze the soil population of mixtures of A. flavus strains. DNA was extracted from each soil sample and used for ddPCR assays. The data indicated that competition between atoxigenic and aflatoxigenic was strain dependent. Variation in competitive ability among different strains of A. flavus influenced the population reduction of the aflatoxigenic strain by the atoxigenic strain. Higher ratios of atoxigenic to aflatoxigenic strains increased soil population of atoxigenic strains. This is the first study to demonstrate the utility of ddPCR to quantify mixtures of both atoxigenic and aflatoxigenic A. flavus strains in soil and allows for rapid and accurate determination of population sizes of atoxigenic and aflatoxigenic strains. This method eliminates the need for isolation and identification of individual fungal isolates from experimental soil samples.

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.

Fungal Deoxynivalenol-Induced Enterocyte Distress Is Attenuated by Adulterated Adlay: In Vitro Evidences for Mucoactive Counteraction

Adlay is a cereal crop that has long been used as traditional herbal medicine and as a highly nourishing food. However, deoxynivalenol (DON), the most prevalent trichothecene mycotoxin worldwide, frequently spoils grains, including adlay, via fungal infection. On the basis of an assumption that the actions of DON in the gut could be modified by adlay consumption, we simulated the impacts of co-exposure in enterocytes and investigated the effectiveness of treatment with adlay for reducing the risk of DON-induced inflammation and epithelia barrier injury. In particular, adlay suppressed DON-induced pro-inflammatory signals such as mitogen-activated kinase transduction and the epidermal growth factor receptor-linked pathway. In addition to regulation of pro-inflammatory responses, adlay treatment interfered with DON-induced disruption of the epithelial barrier. Mechanistically, adlay could boost the activation of protein kinase C (PKC) and cytosolic translocation of human antigen R (HuR) protein, which played critical roles in the epithelial restitution, resulting in protection against disruption of enterocyte barrier integrity. Notably, DON abrogated the Ras homolog gene family member A GTPase-mediated actin cytoskeletal network, which was diminished by adlay treatment in PKC and HuR-dependent ways. Taken together, this study provides evidences for adlay-based attenuation of trichothecene-induced gut distress, implicating potential use of a new gut protector against enteropathogenic insults in diets.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines

The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies.

LAMP-based group specific detection of aflatoxin producers within Aspergillus section Flavi in food raw materials, spices, and dried fruit using neutral red for visible-light signal detection

Aflatoxins can be produced by 21 species within sections Flavi (16 species), Ochraceorosei (2), and Nidulantes (3) of the fungal genus Aspergillus. They pose risks to human and animal health due to high toxicity and carcinogenicity. Detecting aflatoxin producers can help to assess toxicological risks associated with contaminated commodities. Species specific molecular assays (PCR and LAMP) are available for detection of major producers, but fail to detect species of minor importance. To enable rapid and sensitive detection of several aflatoxin producing species in a single analysis, a nor1 gene-specific LAMP assay was developed. Specificity testing showed that among 128 fungal species from 28 genera, 15 aflatoxigenic species in section Flavi were detected, including synonyms of A. flavus and A. parasiticus. No cross reactions were found with other tested species. The detection limit of the assay was 9.03pg of A. parasiticus genomic DNA per reaction. Visual detection of positive LAMP reactions under daylight conditions was facilitated using neutral red to allow unambiguous distinction between positive and negative assay results. Application of the assay to the detection of A. parasiticus conidia revealed a detection limit of 211 conidia per reaction after minimal sample preparation. The usefulness of the assay was demonstrated in the analysis of aflatoxinogenic species in samples of rice, nuts, raisins, dried figs, as well as powdered spices. Comparison of LAMP results with presence/absence of aflatoxins and aflatoxin producing fungi in 50 rice samples showed good correlation between these parameters. Our study suggests that the developed LAMP assay is a rapid, sensitive and user-friendly tool for surveillance and quality control in our food industry.

Prevalence of toxigenic fungi in common medicinal herbs and spices in India

Mycotoxins are unavoidable contaminants of food grains, feeds, medicinal herbs, and spices, posing as health threat to animals and humans. The objective of this study was to screen medicinal herbs and spices for fungi and mycotoxin contamination and evaluate their safety. Sixty-three samples were examined for fungal contamination and fungal load determined using standard microbiological method. Aflatoxin and citrinin were detected using thin layer chromatography and high-performance chromatography technique. Fifty-eight out of the 63 samples were contaminated, while five were free from fungal contamination. Analysis revealed that 47 % of the samples had a fungal load above 1 × 10³ cfu/g which is the permissible limit set by World Health Organization. The samples Mesua ferrea-II and Terminalia chebula-III had the highest fungal load, i.e., 5.0 × 10⁴ cfu/g. A total of 187 fungi were isolated, out of which 28 were toxigenic which included 19 aflatoxin-producing Aspergillus flavus and 9 citrinin-producing Penicillium citrinum. The natural contamination with aflatoxin B₁ was detected only in one sample, i.e., Arachis hypogaea (groundnut) which was present beyond the permissible limit. Though toxigenic fungi were isolated, mycotoxins were not detected from any of the medicinal herbs and spices. Medicinal herbs and spices are susceptible to toxigenic fungi; however, they also possess intrinsic factors that inhibit mycotoxin contamination. This study provides a basis in assessing the degree of fungal and potential mycotoxin contamination in medicinal herbs and spices.

Plant Food Supplements with Antioxidant Properties for the Treatment of Chronic and Neurodegenerative Diseases: Benefits or Risks?

Wine by-products, in particular grape pomace, can be an important source of polyphenols and dietary fibers and are increasingly being used as a starting material in the industrial production of plant food supplements, such as other matrices containing biomolecules, with antioxidant properties. The risk associated with the consumption of these products was recently analyzed through a study of potential genotoxic and carcinogenic compounds that can be found in the marketed products. In particular, occurrence data about contamination with the mycotoxin ochratoxin A were also reported. This short review aims at giving an overview about the quality and benefits of these kinds of food supplements, and also about risks of incorrect use, focusing on the emerging need for stricter European regulations.

Decomposition and detoxification of aflatoxin B1 by lactic acid

BACKGROUND

A degradation study of aflatoxin B1 (AFB1) was carried out using a combination of physical and chemical methods. AFB1 was heated at 80 °C in the presence of acetic, citric and lactic acids for various time periods. The cytotoxicity of the degraded AFB1 and its products were determined by MTT assay.

RESULTS

The results showed that among the three organic acids lactic acid was most efficient in degrading AFB1. Although complete degradation was not observed, up to 85% degradation of AFB1 was obtained when heated for 120 min. Degradation of AFB1 was confirmed by the reduced toxicity on HeLa cells using MTT assay. Treatment with lactic acid resulted in the conversion of AFB1 into two degradation products. These products were observed at lower retention factors of 0.63 and 0.38, which were identified as AFB2 and AFB2a, respectively. The cytotoxicity of AFB2a exhibited much reduced toxicity on HeLa cells compared to that of AFB1.

CONCLUSION

The results have shown the efficiency of lactic acid in degrading AFB1. This study suggest that lactic acid may be considered for use in the food and feed industry since it is present naturally in food and is considered safe.