Occurrence and Characterization of Fungi and Mycotoxins in Contaminated Medicinal Herbs

Simultaneous detection of multiple mycotoxins in Radix Dipsaci and estimation of exposure risk for consumers

Like many traditional Chinese herbal medicines, preparations from Radix Dipsaci are at risk of contamination by harmful mycotoxins; however, there have been no reports of actual contamination. In this study, we developed an analytical method to simultaneously detect eight mycotoxins in Radix Dipsaci and estimate the exposure risk for consumers. We have developed an analytical method utilizing ultra-high performance liquid chromatography and tandem mass spectrometry to accurately determine the levels of AFB1, AFB2, AFG1, AFG2, OTA, ZEN, T-2 and ST mycotoxins in 45 batches of Radix Dipsaci sourced from major medicinal herb markets across five regions in China. We also analyzed migration of mycotoxins from the raw herbs into water decoction. Based on these results and data on human consumption of the herbal medicine, we estimated risk of exposure and acceptable exposure limits to mycotoxins in the Radix Dipsaci using the "margin of exposure (MOE)" method. Of the 45 batches of Radix Dipsaci, 48.89% contained at least one of the eight mycotoxins, 24.44% contained one, 17.78% contained two and 6.67% contained three. The most frequent mycotoxins were aflatoxin B1, present in 35.56% of batches (at 0.25-34.84 μg/kg); aflatoxin G1, 15.56% (1.99-44.05 μg/kg); and ochratoxin A, 22.22% (16.11-143.38 μg/kg). These three mycotoxins transferred from the raw herb into water decoction at respective rates of 20.20%, 29.14%, and 24.80%. The 95th percentile values of the MOE risk factors for health effects of AFB1 were below 10,000 at high doses but above 10,000 at low doses of Radix Dipsaci long-term treatment. With the reduction in duration of exposure years, the MOE values of AFB1 and AFG1 gradually reverted to within the acceptable range. The mean, 50th, and 95th percentile values of the MOE risk factors for health effects of OTA exceeded 10,000 regardless of whether consumers received a low or high dose of Radix Dipsaci treatment for durations ranging from 1 to lifetime. Based on this exposure and a typical human diet, we have estimated the respective 20-year exposure limits for Radix Dipsaci to be 5.821 μg/kg, 4.035 μg/kg, and 56.073 μg/kg for the three mycotoxins under consideration. Contamination with multiple mycotoxins is frequently observed in Radix Dipsaci, and the three most prevalent contaminants have been found to leach into water decoctions, thereby posing a potential health hazard for individuals consuming this herbal preparation. This work highlights the need to monitor herbal medicines for mycotoxin contamination in order to protect consumers.

Evaluation of mycotoxins, mycobiota and toxigenic fungi in the traditional medicine Radix Dipsaci

Medicinal herbs have been increasingly used for therapeutic purposes against a diverse range of human diseases worldwide. However, inevitable contaminants, including mycotoxins, in medicinal herbs can cause serious problems for humans despite their health benefits. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity, and quality of these natural products. Radix Dipsaci is commonly utilized in traditional Chinese medicine and is susceptible to contamination with mycotoxins. Here, we evaluated the mycotoxins, mycobiota and toxigenic fungi in the traditional medicine Radix Dipsaci. A total of 28 out of 63 Radix Dipsaci sample batches (44.4%) were found to contain mycotoxins. Among the positive samples, the contamination levels of AFB1, AFG1, AFG2, and OTA in the positive samples ranged from 0.52 to 32.13 μg/kg, 5.14 to 20.05 μg/kg, 1.52 to 2.33 μg/kg, and 1.81 to 19.43 μg/kg respectively, while the concentrations of ZEN and T-2 were found to range from 2.85 to 6.33 μg/kg and from 2.03 to 2.53 μg/kg, respectively. More than 60% of the contaminated samples were combined with multiple mycotoxins. Fungal diversity and community were altered in the Radix Dipsaci contaminated with various mycotoxins. The abundance of Aspergillus and Fusarium increased in the Radix Dipsaci contaminated with aflatoxins (AFs) and ZEN. A total of 95 strains of potentially toxigenic fungi were isolated from the Radix Dipsaci samples contaminated with mycotoxins, predominantly comprising Aspergillus (73.7%), Fusarium (20.0%), and Penicillium (6.3%). Through morphological identification, molecular identification, mycotoxin synthase gene identification and toxin production verification, we confirmed that AFB1 and AFG1 primarily derive from Aspergillus flavus, OTA primarily derives from Aspergillus westerdijkiae, ZEN primarily derives from Fusarium oxysporum, and T-2 primarily derives from Fusarium graminearum in Radix Dipsaci. These data can facilitate our comprehension of prevalent toxigenic fungal species and contamination levels in Chinese herbal medicine, thereby aiding the establishment of effective strategies for prevention, control, and degradation to mitigate the presence of fungi and mycotoxins in Chinese herbal medicine.

Contamination of the traditional medicine Radix Dipsaci with aflatoxin B1 impairs hippocampal neurogenesis and cognitive function in a mouse model of osteoporosis

BACKGROUND

Aflatoxin B1, which can penetrate the blood-brain barrier and kill neural cells, can contaminate traditional herbal medicines, posing a significant risk to human health. The present study examined cellular, cognitive and behavioral consequences of aflatoxin B1 contamination of the anti-osteoporotic medicine Radix Dipsaci.

METHODS

A mouse model of osteoporosis was created by treating the animals with all-trans-retinoic acid. Then the animals were treated intragastically with water decoctions of Radix Dipsaci that contained detectable aflatoxin B1 or not. The animals were compared in terms of mineral density and mineral salt content of bone, production of pro-inflammatory factors, neurogenesis and microglial activation in hippocampus, as well as behavior and cognitive function.

RESULTS

Contamination of Radix Dipsaci with aflatoxin B1 significantly reduced the medicine's content of bioactive saponins. It destroyed the ability of the herbal decoction to improve mineral density and mineral salt content in the bones of diseased mice, and it induced the production of the oxidative stress marker malondialdehyde as well as the pro-inflammatory cytokines interleukin-1β and tumor necrosis factor-α. Aflatoxin B1 contamination inhibited formation of new neurons and increased the proportion of activated microglia in the hippocampus. These neurological changes were associated with anhedonia, behavioral despair, and deficits in short-term memory and social memory.

CONCLUSION

Contamination of Radix Dipsaci with aflatoxin B1 not only eliminates the herbal decoction's anti-osteoporotic effects, but it also induces neurotoxicity that can lead to cognitive decline and behavioral abnormalities. Such contamination should be avoided through tightly regulated production and quality control of medicinal herbs.

Quantitative Analysis of Fungal Contamination of Different Herbal Medicines in China

Herbal medicines are widely used for clinical purposes worldwide. These herbs are susceptible to phytopathogenic fungal invasion during the culturing, harvesting, storage, and processing stages. The threat of fungal and mycotoxin contamination requires the evaluation of the health risks associated with these herbal medicines. In this study, we collected 138 samples of 23 commonly used herbs from 20 regions in China, from which we isolated a total of 200 phytopathogenic fungi. Through morphological observation and ITS sequencing, 173 fungal isolates were identified and classified into 24 genera, of which the predominant genera were Fusarium (27.74%) and Alternaria (20.81%), followed by Epicoccum (11.56%), Nigrospora (7.51%), and Trichocladium (6.84%). Quantitative analysis of the abundance of both Fusarium and Alternaria in herbal medicines via RT-qPCR revealed that the most abundant fungi were found on the herb Taraxacum mongolicum, reaching 300,000 copies/μL for Fusarium and 700 copies/μL for Alternaria. The in vitro mycotoxin productivities of the isolated Fusarium and Alternaria strains were evaluated by using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and it was found that the Fusarium species mainly produced the acetyl forms of deoxynivalenol, while Alternaria species mainly produced altertoxins. These findings revealed widely distributed fungal contamination in herbal medicines and thus raise concerns for the sake of the quality and safety of herbal medicines.

Variations of the fungal microbiome in Corydalis Rhizoma with different collection areas, processing methods, and storage conditions

Corydalis Rhizoma (CR, Yanhusuo in Chinese) has been widely used as an analgesic in herbal medicine and functional food. Cases of fungal and mycotoxin contamination in CR have been reported. In this study, the composition and diversity of fungal microbiome in CR samples from four herbal markets and two processing methods were investigated by DNA metabarcoding. Variations of the fungal microbiome in CR during cold and conventional storage were monitored. Results showed that Aspergillus was the dominant genus and saprotroph was the dominant trophic mode. Six potential toxigenic fungi, namely, Aspergillus fumigatus, Aspergillus ostianus, Aspergillus terreus, Penicillium citrinum, Penicillium oxalicum, and Trichothecium roseum, were detected. Differences in fungal composition and diversity among various groups based on collection areas and processing methods were also observed. Moreover, the relative abundance of dominant genera in CR samples stored at different temperatures was significantly different and changed with storage time. This study is the first to reveal the influence of collection areas, processing methods, and storage conditions on the fungal microbiome in CR, which was expected to provide a basis for control strategies of fungal contamination in the industrial chain of CR.

Highly Sensitive Microarray Immunoassay for Multiple Mycotoxins on Engineered 3D Porous Silicon SERS Substrate with Silver Nanoparticle Magnetron Sputtering

A high-throughput, rapid, and highly sensitive surface-enhanced Raman spectroscopy (SERS) microarray for screening multiple mycotoxins has been developed on a three-dimensional silver nanoparticle porous silicon (3D AgNP-Psi) SERS substrate, which was easy to be engineered by electrochemical etching and magnetron sputtering technology. The etching current density, etching waveform, and target material for magnetron sputtering have been investigated to obtain an optimal 3D SERS substrate. The optimized 3D AgNP-Psi SERS substrate showed an enhancement factor of 2.3 × 107 at 400 mA/cm2 constant current density etching for 20 s and Ag target magnetron sputtering for 200 nm thickness on the surface of Psi. The simulation electric field distribution showed the near-field enhancement can reach 3× higher than that of AuNPs. A protein microarray has been designed to screen multiple mycotoxins by AuNP Raman tags and a competitive immunoassay protocol on the surface of the 3D SERS substrate. The SERS protein microarray displayed wide linear detection ranges of 0.001-100 ng/mL for ochratoxin A, 0.01-100 ng/mL for aflatoxin B1, 0.001-10 ng/mL for deoxynivalenol, along with pg/mL low limit of detection, good recovery rates, repeatability, and reproducibility. The 3D SERS protein microarray is easily engineered and has a great potential application in medicine, environment, and food industry fields.

Continuous cropping disorders of eggplants (Solanum melongena L.) and tomatoes (Solanum lycopersicum L.) in suburban agriculture: Microbial structure and assembly processes

Deciphering the intricate relationships between microorganisms and plants remains a formidable challenge in plant microbial ecology, an area that holds promise for optimizing microbial interventions to enhance stress resilience and agricultural yields. In our investigation, we procured samples during 2019 and 2022 from a suburban agricultural greenhouse. Our study delineated the composition of bacterial and fungal communities across various ecological niches-namely, the rhizosphere soil, bulk soil, and phyllosphere of healthy, Ralstonia solanacearum-infected, and dead eggplants and tomatoes. The structure and composition of both fungal and bacterial communities change significantly under the influence of the host genotype across all samples. In the tomato or eggplant groups, bacterial wilt exerts a more pronounced impact on the bacterial community than on the fungal community. We speculate that the rhizosphere of healthy eggplants and tomatoes harbored more antibiotic-producing (e.g., Amycolatopsis and Penicillium) and biocontrol (e.g., Bacillus) strains, which can lead to have lower absolute abundance of R. solanacearum. In the context of R. solanacearum invasion, deterministic processes were responsible for shaping 70.67 % and 80.63 % of the bacterial community assembly in the rhizosphere of eggplants and tomatoes, respectively. Deterministic processes dominated the assembly of fungal communities in the rhizosphere of R. solanacearum-infected eggplants, whereas the opposite was true in the tomatoes. Homogeneous selection emerged as the predominant force governing the bacterial community assembly in the rhizospheres of R. solanacearum-infected eggplants and tomatoes. The bacterial co-occurrence networks in healthy rhizosphere soil were characterized by reduced vulnerability and enhanced stability (i.e., robustness index) and complexity (i.e., cohesion index), compared to their infected counterparts. In summary, complex microbial networks in rhizosphere soils are more resistant to invasion by soil-borne pathogens. The dynamics of bacterial interactions and community assembly processes are pivotal for effective microbiome management and offer predictive insights into the ecological ramifications of R. solanacearum invasions.

Determination of ochratoxin A in licorice extract based on modified immunoaffinity column clean-up and HPLC analysis

Contamination of ochratoxin A (OTA) is a common concern for the quality and safety of licorice and its derivatives, while their complex sample matrices always restrict the monitoring and regulation of OTA. Taking the much more concentrated and complicated licorice extract as the representative, a modified analysis method was established for OTA by HPLC. Parameters were comprehensively investigated based on liquid-liquid extraction and immunoaffinity column clean-up. In comparison to other methods, the developed method achieved effective clean-up efficiency and selectivity without tedious procedures and specialized instrumentation. Good linearity (R2 ≥0.9995), low LOD/LOQ (0.10 μg/kg/0.33 μg/kg), and satisfactory recovery (90.0%-96.4%, RSDs <7.0%) indicated the satisfactory sensitivity and reliability of the method. In addition, the applicability and robustness of the method was demonstrated by the analysis of large numbers of licorice extract samples. It is noteworthy that 66.5% of 176 samples were contaminated with OTA, while the concentrations of 9.1% of samples exceeded the maximum limit (ML, 80 μg/kg) defined by the EU. On account of the high contamination frequency and broad concentration range of OTA, the daily intake limit of licorice extract was preliminarily determined to be 123.18-123.93 g/day (chronic exposure) and 24.24 g/day (acute exposure), indicating a potential of acute risk through daily exposure. This calls for improved supervision and regulation for OTA contamination in licorice samples. This study suggests a prospective option for the efficient determination and routine monitoring of OTA in licorice and its derivatives, simultaneously providing a valuable data base for its health risk assessment.

Occurrence of fungi and mycotoxins in herbal medicines and rapid detection of toxin-producing fungi

Contamination from external hazardous materials may greatly influence the safety and efficacy of herbal medicines. This paper aimed to evaluate the levels of contamination by mycotoxins and toxigenic fungi in herbal medicines and establish a rapid method for detecting toxin-producing fungi. Herein, 62.92%, 36.25%, and 64.17% of herbal medicines were contaminated by aflatoxins (AFs), ochratoxins, and fumonisins, respectively. Aspergillus (43.77%), Fusarium (5.17%), and Cladosporium (4.46%) were the three predominant genera. Spearman's correlation results showed that Aspergillus and Fusarium were significantly and positively correlated with mycotoxin content (R > 0.5, P < 0.05). In addition, 323 fungal strains were isolated from herbal medicines, and 20 species were identified, mainly belonging to Aspergillus and Penicillium. Analysis of potential mycotoxin-producing fungi showed that Aspergillus flavus can produce AFs, and Aspergillus ochraceus and Aspergillus niger can produce ochratoxin A (OTA). Multiplex real-time polymerase chain reaction showed that A. flavus harbored AF synthesis genes (aflR), and A. ochraceus and A. niger harbored OTA synthesis genes (aoksl). With these synthesis genes, 67.07% and 37.20% of 164 herbal medicines were positive for toxigenic genes. Furthermore, an excellent correlation was found between the above gene copies and mycotoxin content (R2 = 0.99). Our results confirmed the high detection rate of mycotoxins in herbal medicines and identified pivotal AF- and OTA-producing fungi. In conclusion, this paper provided the contamination status of fungi and mycotoxins in herbal medicines and established a rapid method for detecting toxigenic fungi.

Sampling locations and processing methods shape fungi microbiome on the surface of edible and medicinal Arecae semen

Introduction

Arecae semen, which is derived from the dried ripe seed of Areca catechu L., has been commonly used as one of the major traditional Chinese medicines (TCMs). Three types of crude herbal preparations, namely, raw Arecae semen (AS), Arecae semen tostum (SAS), and Arecae semen carbonisata (FAS), are available for different clinical applications in TCMs. Although aflatoxin contamination in Arecae semen has been reported preliminarily, only a few studies have been conducted on fungal contamination.

Methods

In this study, the presence of fungi on the surface of three Arecae semen (AS, SAS, and FAS) that collected from four provinces were investigated using high-throughput sequencing and internal transcribed spacer 2.

Results

Results showed that the phyla Ascomycota (75.45%) and Basidiomycota (14.29%) and the genera Wallemia (7.56%), Botryosphaeria (6.91%), Davidiella (5.14%), and Symbiotaphrina (4.87%) were the dominant fungi, and they presented significant differences in four areas and three processed products (p < 0.05). The α-diversity and network complexity exhibited significant differences in the four sampling locations (p < 0.05), with higher in Yunnan (Chao 1, 213.45; Shannon, 4.61; average degree, 19.96) and Hainan (Chao 1, 198.27; Shannon, 4.21; average degree, 22.46) provinces. Significant differences were noted in the three processed samples; and SAS group had highest α-diversity (Chao 1, 167.80; Shannon, 4.54) and network complexity (average degree, 18.32).

Conclusions

In conclusion, the diversity and composition of microbiome on the surface of Arecae semen were shaped by sampling location and processing methods. This work provides details on the surface microbiome of Arecae semen samples and highlights the importance of roles of origin and processing methods in microbiomes, ensuring drug efficacy and food safety.

Analysis of 16 mycotoxins in genuine traditional Chinese medicine for five medicinal parts: Classification of analytical method based on PANI@CS extraction-UPLC-MS/MS

A novel PANI@CS solid-phase dispersive extractant combined with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed for the first time, which was used for high-throughput, multi-component, real-time online rapid pretreatment and quantitative classification of 16 mycotoxins from five different medicinal parts of 13 genuine traditional Chinese medicines (TCMs). Ultra performance liquid chromatography combined with triple quadrupole mass spectrometry was used for separation and ESI detection. An internal standard isotope matching calibration was used for quantification purposes to compensate for matrix effects. The limits of detection (LOD) of 16 mycotoxins ranged from 0.1 to 6.0 μg/kg. The linear coefficients (R²) were ≥0.996 in the linear range from 10.0 to 200 μg/L. The recoveries of the 16 mycotoxins ranged from 90.1% to 105.8%, and the relative standard deviations (RSDs) ranged from 1.3% to 4.1%. Thirteen TCMs from five representative medicinal parts were selected and tested under the best sample preparation procedure and chromatographic analysis conditions. The results showed that the method could improve the sensitivity and accuracy of the sample analysis, improve the selectivity and reproducibility of the decolorization and purification of TCMs, which is suitable for the practical application of mycotoxin in trace analysis. This method can also provide a new idea for accurate, efficient, rapid and multi-component online detection of mycotoxins for quality and safety control of TCMs.

The Mechanism of Ochratoxin Contamination of Artificially Inoculated Licorice Roots

Ochratoxin (OT) contamination of medicinal herbs is a serious threat to human health. This study was performed to investigate the mechanism of OT contamination of licorice (Glycyrrhiza sp.) root. Licorice root samples were cut into eight parts, which were placed separately on sucrose-free Czapek Dox agar medium, inoculated with the spores of ochratoxigenic Aspergillus westerdijkiae. After incubation for 10 and 20 days, the OT contents of the samples were determined by high-performance liquid chromatography, and microtome sections prepared from the samples were analyzed by desorption electrospray ionization tandem mass spectrometry, to visualize OT localization. The same sections were further examined by light microscopy and scanning electron microscopy, to investigate the path of fungal mycelial penetration of the inner roots. OT concentrations tended to increase from the upper- to the middle-root parts. OTs were located in cut areas and areas of cork layer damage; they were not present in the undamaged cork layer, indicating that the structure of this layer prevents OT contamination of the licorice root.

Characterization of the Fungal Community in Fritillariae Cirrhosae Bulbus through DNA Metabarcoding

Fritillariae Cirrhosae Bulbus (FCB) is a well-known and precious traditional Chinese medicine with a medicinal history spanning thousands of years. In recent years, it has been reported that fungal and mycotoxin contamination influenced the safety and quality of FCB. It is essential to systematically study the fungal community for the early warning of fungal and mycotoxin contamination in this herb. A total of 15 FCB samples were collected from five provinces in China, and the fungal communities in the FCB samples were analyzed via amplifying the internal transcribed spacer 2 region through the Illumina Miseq PE300 platform. Furthermore, we compared the differences in fungal community in five groups based on collection areas. Results showed that Ascomycota (41.58-99.66%) and Mucoromycota (0-57.42%) were dominant at the phylum level. Eurotiomycetes (8.49-63.93%), Eurotiales (8.49-63.53%), and Aspergillaceae (8.49-63.51%) were the most abundant at the class, order, and family levels. Aspergillus (8.49-63.41%), Rhizopus (0-57.42%), Fusarium (0-22.81%), Cladosporium (0.16-9.14%), and Alternaria (0.06-17.95%) were the main genera in FCB samples. A total of 34 fungal taxa were identified at the species level, including five potentially toxigenic fungi namely Penicillium brevicompactum, P. citrinum, P. oxalicum, Trichothecium roseum, and Aspergillus restrictus. The differences in fungal community between the five groups were observed. Our findings provide references for the safe utilization and quality improvement of FCB.

Mycotoxins occurrence in medicinal herbs dietary supplements and exposure assessment

The multimycotoxin analysis of aflatoxins (AFs), zearalenone (ZEA), ochratoxin A (OTA), enniatins (ENNs) and beauvericin (BEA) was performed in 85 samples of medicinal herbs dietary supplements. The samples were classified in 64 samples of one herbal ingredient and 21 mixed samples. The extraction was performed by QuEChERS method and the determination by liquid chromatography coupled to ion-trap tandem mass spectrometry (LC–MS/MS-IT). Then, the risk characterization to mycotoxins through the consumption of medicinal herbs dietary supplements was assessed. The results showed that ZEA, OTA, ENNs and BEA showed in the samples with incidences between 1 and 34%, being ENNB the most detected mycotoxin. Mycotoxins contents ranged from LOQ to 3850.5 µg/kg while the mean of positives samples were 65.5 µg/kg (ENNA), 82.7 µg/kg (ENNA1), 88.7 µg/kg (ENNB), 324.9 µg/kg (ENNB1), 137.9 µg/kg (BEA) and 1340.11 µg/kg (ZEA), respectively. OTA was detected in one herbal mix tablet for insomnia at concentration of 799 μg/kg. In herbal drugs the European Pharmacopoeia Commission has implemented limits of 2 µg/kg for AFB1 and 4 µg/kg for total AFs. In the present study AFs have not been detected in the analyzed medicinal herbs dietary supplements. The Estimated Daily Intakes (EDIs) values were calculated using a deterministic method, considering two exposure scenarios (lower bound (LB) and upper bound (UB)). The values obtained were in general far below the Tolerable Daily Intakes (TDIs) established.

Exposure assessment and risk-based limit levels evaluation of ochratoxin A in Astragali Radix in China

Ochratoxin A (OTA) is a mycotoxin found in a variety of foods and herbal medicines, and several governmental bodies around the world have set maximum allowable levels of OTA in different foods and herbal medicines. This study aims to evaluate the health risk of OTA in Astragali Radix (AR) in China, and to evaluate the effects of different limit levels on the risk control of OTA in AR. The concentrations of OTA in 187 samples of AR were investigated, and 61 (32.6%) samples were positive. The mean, 50th and 95th percentile values of OTA in positive samples were 56.2, 5.1 and 304.5 μg/kg, respectively. A margin of exposure (MOE) approach was applied to assess the risk. Considering other food sources, long-term consumers have a relatively high risk of OTA exposure due to the ingestion of AR. Theoretical limit levels of OTA in AR were evaluated from two dimensions by weighing the costs and the benefits. The results indicated that the limit levels that might be applied to the management of OTA contamination in AR in China could be screened out through risk-based evaluation of limit levels.

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.

Impacts of continuous and rotational cropping practices on soil chemical properties and microbial communities during peanut cultivation

Long-term monocultures have severely inhibited the cultivation of Chinese peanut (Arachis hypogaea L.). In this study, the effects of continuous cropping on soil chemical properties and microbial communities were investigated in peanut fields that had been in crop rotation for 10 years and in monoculture for 10 years. The results found that long-term monoculture increased the activities of available potassium, available phosphorus, available nitrogen, soil organic matter, urease, acid phosphatase and catalase; while decreasing the activity of catalase. The diversity and abundance of soil bacteria and fungi is higher under continuous peanut cultivation. At the genus level, the relative abundance of potentially beneficial microflora genera was higher in the rhizosphere soil of rotational cropping than in continuous cropping, while the opposite was true for the relative abundance of potentially pathogenic fungal genera. Principal coordinates and cluster analysis indicated that continuous cropping altered the structure of the microbial community. The results of the functional predictions showed significant differences in the functioning of the rhizosphere microbial community between continuous and rotational cropping. In conclusion, long-term continuous cropping changed the chemical properties of the soil, altered the structure and function of the soil bacterial and fungal communities in peanut rhizosphere, which to some extent reduced the relative abundance of potentially beneficial microbial genera and increased the relative abundance of potentially pathogenic fungal genera, thus increasing the potential risk of soil-borne diseases and reducing the yield and quality of peanut. Therefore, in the actual production process, attention should be paid not only to the application of chemical fertilizers, but also to crop rotation and the application of microbial fertilizers.

Zeolitic imidazolate framework-8 as a dispersive solid phase extraction sorbent for simultaneous determination of 145 pesticide residues in polyphenol-rich plants

Many plants showed higher polyphenol content, which caused the matrix effect and made the analysis of trace pesticide residues highly challenging. A common approach to improving matrix effects is to purify pesticides through the use of sorbents, but this requires a combination of multiple sorbents and extensive use. Zeolitic imidazolate framework-8 is widely used for pesticide analysis due to its high porosity, large specific surface area and versatility. Here, We established and validated a modified quick, easy, cheap, effective, rugged, and safe method based on a zeolitic imidazolate framework-8 that was used to test the removal ability for polyphenols. And 145 pesticide residues in peppermint, perilla, fennel, and mulberry leaves were analyzed by the modified method coupled with LC-MS/MS. The mean recoveries of all pesticide residues were in the range of 74.3%-103.7%, with mean relative standard deviations≤ 9.1% at spiked concentrations of 1, 10, 50, and 100 μg kg^-1 for mulberry leaves. The limits of quantitation of the method ranged from 1 to 50 μg kg^-1 . This study offers a reliable approach for the accurate quantitative analysis of various trace substances in the polyphenol-rich plants. This article is protected by copyright. All rights reserved.

Mycotoxins in herbal tea: transfer into the infusion

Mycotoxins are natural food contaminants, associated with adverse health effects due to acute intoxication and, what is much more common, chronic exposure. The most hazardous and widespread mycotoxins are subjected to regulation in food in most countries. Alongside with regulated, a wide list of mycotoxins is monitored in various foods. Traditionally mycotoxins in tea are determined in a dry sample, not taking into account their transfer rate into the infusion. This study was aimed at the determination of the transfer rate of several mycotoxins from naturally contaminated herbal tea samples into an infusion. Seven of the most contaminated samples were pre-selected during the monitoring of mycotoxins in Camellia sinensis and herbal tea available in the Russian Federation. Ochratoxin A (OTA), sterigmatocystin (STE), mycophenolic acid (MPA), tentoxin (TTX), alternariol (AOH), its methyl ether (AME), zearalenone (ZEN), enniatins A and B (ENN A and B), beauvericin (BEA) were detected in these samples in the range of several μg/kg to several mg/kg. HPLC-MS/MS was used for dry tea samples and their infusion analysis. Mycotoxin polarity and infusion pH (for analytes possessing carboxylic groups) appeared to be factors determining transfer rate. STE transferred into infusion at the average rate of 10%. Average transfer of Alternaria toxins varied from 73% (TTX) to 45% (AOH) and about 11% (AME). A third part of ZEN was detected in the infusion. Transfer of ENNs and BEA was low and did not exceed 7%. Infusion pH affected MPA transfer rate; it increased from 23% to 96% in the pH range from 5.5 to 6.3. 83% of OTA was detected in the infusion of a single contaminated sample. Consideration of the mycotoxin transfer rate to herbal tea infusions resulted in the change of the model herbal tea input into mean chronic dietary exposure for most studied mycotoxins.

Distribution of Aspergillus Fungi and Recent Aflatoxin Reports, Health Risks, and Advances in Developments of Biological Mitigation Strategies in China

Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus Aspergillus flavus, which are abundantly distributed across agricultural commodities. AF contamination is receiving increasing attention by researchers, food producers, and policy makers in China, and several interesting review papers have been published, that mainly focused on occurrences of AFs in agricultural commodities in China. The goal of this review is to provide a wider scale and up-to-date overview of AF occurrences in different agricultural products and of the distribution of A. flavus across different food and feed categories and in Chinese traditional herbal medicines in China, for the period 2000-2020. We also highlight the health impacts of chronic dietary AF exposure, the recent advances in biological AF mitigation strategies in China, and recent Chinese AF standards.

Citrinin Dietary Exposure Assessment Approach through Human Biomonitoring High-Resolution Mass Spectrometry-Based Data

Citrinin (CIT) is a scarcely studied mycotoxin within foodstuffs, so the biomonitoring of this toxin and its metabolite dihydrocitrinone (DH-CIT) in biological samples represents the main alternative to estimate the exposure. Hence, this study aimed to evaluate the presence of CIT and DH-CIT in 300 urine samples from Italian individuals in order to assess the exposure. Quantification was performed through an ultrahigh-performance liquid chromatography high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS)-based methodology. CIT was quantified in 47% of samples (n = 300) up to 4.0 ng/mg Crea (mean = 0.29 ng/mg Crea), whereas DH-CIT was quantified in 21% of samples up to 2.5 ng/mg Crea (mean = 0.39 ng/mg Crea). Considering different age groups, average exposure ranged from 8% to 40% of the provisional tolerable daily intake, whereas four individuals surpassed the limits suggested by the European Food Safety Authority. These results revealed non-negligible exposure levels to CIT, encouraging further investigation in foodstuffs monitoring studies.

Tea: Transfer of Mycotoxins from the Spiked Matrix into an Infusion

Recent surveys report the occurrence of Aspergillus and Penicillium metabolites (aflatoxins (AFLs), ochratoxin A (OTA), cyclopiazonic and mycophenolic acids (MPA), sterigmatocystin (STC), citrinin), Fusarium (trichothecenes, zearalenone (ZEA), fumonisins (FBs), enniatins (ENNs)) and Alternaria (alternariol (AOH), its methyl ether (AME), tentoxin (TE), and tenuazonic acid (TNZ)) toxins in dry Camellia sinensis and herbal tea samples. Since tea is consumed in the form of infusion, correct risk assessment needs evaluation of mycotoxins’ transfer rates. We have studied the transfer of AFLs, OTA, STC, deoxynivalenol (DON), ZEA, FBs, T-2, and HT-2 toxins, AOH, AME, TE, ENN A and B, beauvericin (BEA), and MPA from the spiked green tea matrix into an infusion under variation of preparation time and water characteristics (total dissolved solids (TDS) and pH). Analytes were detected by HPLC-MS/MS. The main factors affecting transfer rate proved to be mycotoxins’ polarity, pH of the resulting infusion (for OTA, FB2, and MPA) and matrix-infusion contact period. The concentration of mycotoxins increased by 20–50% within the first ten minutes of infusing, after that kinetic curve changed slowly. The concentration of DON and FB2 increased by about 10%, for ZEA, MPA, and STC it stayed constant, while for T-2, TE, AOH, and AFLs G1 and G2 it went down. Maximum transfer correlated well with analytes polarity. Maximum transfer of ENNs, BEA, STC, ZEA, and AOH into infusion was below 25%; AFLs—25–45%; DON, TE, and T-2 toxins 60–90%, FB1—80–100%. The concentration of OTA, MPA, and FB2 in the infusion depended on its pH. At pH about four, 20%, 40%, and 60% of these toxins transferred into an infusion, at pH about seven, their concentrations doubled. Water TDS did not affect transfer significantly.

Development a multi-immunoaffinity column LC-MS-MS method for comprehensive investigation of mycotoxins contamination and co-occurrence in traditional Chinese medicinal materials

Mycotoxins are poisonous secondary fungal toxic metabolites and harmful to human health. Traditional Chinese medicinal materials (TCMs), including more than two hundred functional foods, are vulnerably bred fungi, causing spoilage and multi-mycotoxins contamination. This study established a simultaneous analytical method by using multi-mycotoxins immunoaffinity column (multi-IAC) and HPLC-MS/MS to evaluate mycotoxins' contamination levels and natural incidence in TCMs. Aflatoxins (AFs, including AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), fumonisins (FB1 and FB2), zearalenone (ZEN), deoxynivalenol (DON) and T-2 toxins in three TCMs or functional foods of Polygalae Radix (PR), Coicis Semen (CS) and Eupolyphaga Steleophaga (ES) were detected. The systematically investigated results of 30 batch AFB1 positive samples revealed co-occurrence and correlation of multi-mycotoxins are significant differences in various matrices. All the samples in this study contain more than 5 mycotoxins. AFB1-AFs, AFB1-FBs, AFB1-DON, and AFB1-T-2 are the most observed co-occurrence, AFB1-OTA is also of concern due to its synergistic toxicity. This study's results can be used to establish guidelines for screening mycotoxin contaminants and limitations on acceptable levels in TCMs. Simultaneously, mycotoxin's correlation results in different matrices can also provide a reference for the standardization of TCM production and processing.

Soil Metagenomics Reveals Effects of Continuous Sugarcane Cropping on the Structure and Functional Pathway of Rhizospheric Microbial Community

The continuous cropping of plants can result in the disruption of the soil microbial community and caused significant declines in yields. However, there are few reports on the effects of continuous cropping of sugarcane on the microbial community structure and functional pathway. In the current study, we analyzed the structural and functional changes of microbial community structure in the rhizospheric soil of sugarcane in different continuous cropping years using Illumina Miseq high-throughput sequencing and metagenomics analysis. We collected rhizosphere soils from fields of no continuous cropping history (NCC), 10 years of continuous cropping (CC10), and 30 years of continuous cropping (CC30) periods in the Fujian province. The results demonstrated that continuous sugarcane cropping resulted in significant changes in the physicochemical properties of soil and the composition of soil bacterial and fungal communities. With the continuous cropping, the crop yield dramatically declined from NCC to CC30. Besides, the redundancy analysis (RDA) of the dominant bacterial and fungal phyla and soil physicochemical properties revealed that the structures of the bacterial and fungal communities were mainly driven by pH and TS. Analysis of potential functional pathways during the continuous cropping suggests that different KEGG pathways were enriched in different continuous cropping periods. The significant reduction of bacteria associated with rhizospheric soil nitrogen and sulfur cycling functions and enrichment of pathogenic bacteria may be responsible for the reduction of effective nitrogen and total sulfur content in rhizospheric soil of continuous sugarcane as well as the reduction of sugarcane yield and sugar content. Additionally, genes related to nitrogen and sulfur cycling were identified in our study, and the decreased abundance of nitrogen translocation genes and AprAB and DsrAB in the dissimilatory sulfate reduction pathway could be the cause of declined biomass. The findings of this study may provide a theoretical basis for uncovering the mechanism of obstacles in continuous sugarcane cropping and provide better guidance for sustainable development of the sugarcane.

Discovering Penicillium polinicum with High-Lytic Capacity on Helianthus tuberosus Tubers: Oil-Based Preservation for Mold Management

During preservation, Jerusalem artichoke (JA) tubers are subjected to deterioration by mold fungi under storage, which signifies a serious problem. A new blue mold (Penicillium polonium) was recorded for the first time on JA tubers. Penicillium mold was isolated, identified (morphologically, and molecularly), and deposited in GenBank; (MW041259). The fungus has a multi-lytic capacity, facilitated by various enzymes capable of severely destroying the tuber components. An economic oil-based procedure was applied for preserving and retaining the nutritive value of JA tubers under storage conditions. Caraway and clove essential oils, at a concentration of 2%, were selected based on their strong antifungal actions. JA tubers were treated with individual oils under storage, kept between peat moss layers, and stored at room temperature. Tubers treated with both oils exhibited lower blue mold severity, sprouting and weight loss, and higher levels of carbohydrates, inulin, and protein contents accompanied by increased levels of defense-related phytochemicals (total phenols, peroxidase, and polyphenol oxidase). Caraway was superior, but the results endorse the use of both essential oils for the preservation of JA tubers at room temperature, as an economic and eco-safe storage technique against the new blue mold.

Mycotoxin Contamination Concerns of Herbs and Medicinal Plants

Plants and medicinal herbs that are available on the market do not always meet quality and safety standards. One particular concern is the risk of contamination with mycotoxins. Aflatoxins and ochratoxin A are the most frequently described mycotoxins in herbal products and have repeatedly been reported to occur at concentrations which exceed regulatory levels set by the European Union (EU). Possible solutions include enforcing existing limits, and for the new materials, establishing tighter limits and mandate the growth of medicinal plants in EU member countries under more strict conditions.