Mycotoxin contamination in the Arab world: Highlighting the main knowledge gaps and the current legislation

Since the discovery of aflatoxins in the 1960s, knowledge in the mycotoxin research field has increased dramatically. Hundreds of review articles have been published summarizing many different aspects, including mycotoxin contamination per country or region. However, mycotoxin contamination in the Arab world, which includes 22 countries in Africa and Asia, has not yet been specifically reviewed. To this end, the contamination of mycotoxins in the Arab world was reviewed not only to profile the pervasiveness of the problem in this region but also to identify the main knowledge gaps imperiling the safety of food and feed in the future. To the best of our knowledge, 306 (non-)indexed publications in English, Arabic, or French were published from 1977 to 2021, focusing on the natural occurrence of mycotoxins in matrices of 14 different categories. Characteristic factors (e.g., detected mycotoxins, concentrations, and detection methods) were extracted, processed, and visualized. The main results are summarized as follows: (i) research on mycotoxin contamination has increased over the years. However, the accumulated data on their occurrences are scarce to non-existent in some countries; (ii) the state-of-the-art technologies on mycotoxin detection are not broadly implemented neither are contemporary multi-mycotoxin detection strategies, thus showing a need for capacity-building initiatives; and (iii) mycotoxin profiles differ among food and feed categories, as well as between human biofluids. Furthermore, the present work highlights contemporary legislation in the Arab countries and provides future perspectives to mitigate mycotoxins, enhance food and feed safety, and protect the consumer public. Concluding, research initiatives to boost mycotoxin research among Arab countries are strongly recommended.

Toxicogenic Fungi, Aflatoxins, and Antimicrobial Activities Associated with Some Spices and Herbs from Three Selected Markets in Ho Municipality, Ghana

Spices and herbs are widely used food ingredients that enhance most organoleptic features of prepared foods. They are also used for medicinal and preservative purposes. Spices and herbs are potential carriers of bacteria, yeasts, and molds due to the nature of cultivation, harvest methods, storage conditions, packaging procedures, distribution, sale, and general handling. Although some fungi have been identified to be associated with most spices and herbs elsewhere in the world, little has been done on the presence of fungi in spices and herbs in Ghana. This study sought to identify the toxicogenic fungal profiles, mycotoxins (aflatoxins) present in some herbs, bay leaf (Laurus nobilis) and garden egg leaves (“gboma”) (Solanum macrocarpon), and spices, ginger (Zingiber officinale) and “dawadawa”(Parkia biglobosa), as well as to investigate the antimicrobial properties of the selected herbs and spices. The decimal reduction technique was used to plate onto Dichloran Rose Bengal Chloramphenicol (DRBC) agar media plates for fungal growth. Aflatoxin detection was carried out with high-performance liquid chromatographer connected to a fluorescence detector (HPLC-FLD). Antimicrobial properties were carried out using the agar diffusion method on solidified, freshly prepared Mueller-Hinton agar. A total of 12 species belonging to 7 genera, Aspergillus (niger, flavus, fumigatus, and ochraceus), Fusarium (oxysporum, verticillioides), Mucor (racemosus), Penicillium (digitatum, expansum), Rhizopus (stolonifer), Rhodotorula sp., and Trichoderma harzianum, were identified as fungal contaminants. Fusarium oxysporum was the most predominant species identified. Fresh ginger recorded the greatest number of colony-forming units (3.71 log10 CFU/g) with bay leaves recording the least number of colony counts (2.36 log10 CFU/g). Mycotoxin concentration detected in gboma was $2.06\pm 0.07\mu \text{g}/\text{kg}$ and in dawadawa was $2.13\pm 0.09\mu \text{g}/\text{kg}$ ; however, mycotoxins were not detected in bay leaf and ginger. Ginger exhibited antibacterial activity against all bacteria ranging from $7.0\pm 0.0\text{mm}$ to $12.0\pm 5.66\text{mm}$ zones of inhibition. Ginger, bay leaf, and gboma extracts displayed fair antimicrobial activity against the bacteria investigated. On the other hand, dawadawa generally produced the least resistance against the five bacterial species but exhibited the highest zone of inhibition. All samples were slightly acidic with pH readings ranging from 5.81 to 6.76.

Substantive Morphological Descriptions, Phylogenetic Analysis and Single Nucleotide Polymorphisms of Aspergillus Species From Foeniculum vulgare

Ascomycetous fungi are found associated with a wide variety of substrates which range from fresh water to marine ecosystems, tropical to temperate forest soils and deserts, throughout the world over. These demystifying fungi exist as endophytes, pathogens and saprobes. They have been studied due to their ability to contaminate foods and feedstuffs, causing an elaboration of mycotoxins. The objectives of the study included extensive analyses of the morphological features of fungi, especially Aspergilli, which have been presented while studying them on specific mycological media. It is also an elaborate compilation of substantive macro- and micro-morphological characterization of different Aspergilli isolated from the spice Foeniculum vulgare used in India and other countries in the world. Further, a first of its kind attempt has been made to study their relative abundance and frequency of occurrence, molecular phylogeny and genetic relatedness to characterize the Aspergilli into specific sections, groups and clades. Single nucleotide polymorphism (SNP) analysis was carried out to evaluate the functional consequences of nucleotide variations, synonymous and non-synonymous mutations in the protein structure. The study resulted in a total of 3,506 Aspergillus isolates, which were obtained from seventy (70) fennel samples, representing 14 Aspergillus species. The two most frequently found species were A. niger and A. flavus with a relative abundance of 32.24 and 11.63%, respectively. The taxonomy and current placements have been reappraised with suggestions and prospects for future research from six sections namely Terrei, Flavi, Fumigati, Nidulantes, Nigri, and Versicolores. In addition, a total number of 27 isolates were studied and deposited at the National Centre for Biotechnology Information (NCBI) and five Aspergillus species have been identified and are being reported for the first time from the fennel seeds, based on partial sequence analysis of the official fungal barcode namely, Internal Transcribed Spacer (ITS) and a functional gene, beta tubulin gene locus, coupled with phenotypic characterization. SNPs for specific DNA regions have been used to identify variants in Aspergilli obtained from Indian fennel seeds for the first time. The need for a polyphasic approach of morphological identification and genetic characterization of Aspergilli from Foeniculum vulgare is addressed and presented here in adequate detail. Our current work makes extensive use of partial beta-tubulin gene sequences analyses to evaluate the association between SNPs in five Aspergillus species sections.

Survey of aflatoxins and ochratoxin A contamination in spices by HPLC-based method in Shiraz, Southern of Iran

Among food and agricultural products, spices play important roles in the diets of millions of people worldwide. These products may be colonized by fungi genus and subsequently mycotoxin production. Due to the large demand and supply of spice for cooking, preservative effects, or medicine purpose, it is essential that further investigation is designed to examine mycotoxins in spice. In the present study, the possible contamination of spices by aflatoxins (AFTs) and ochratoxin A (OTA) were analyzed. A total of 80 spice samples (curry, sumac, ginger, and saffron) were purchased and cultured on appropriate medium. Simultaneously mycotoxins from spices were extracted with immunoaffinity columns (IAC), and the occurrence of AFTs (B1 + B2 + G1 + G2) and OTA was then determined using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). The results depicted that 62 (77.5%) and 58 (72.5%) spice samples were contaminated with AFTs and OTA, respectively. Out of the 80 analyzed spices samples, the mean concentration of AFTs and OTA was higher in the curry samples. Among spices that contaminated with mycotoxins, 5 (6.25%) and 2 (10%) of the samples were above the acceptable limit of AFTs (≥ 10 μg/kg) and OTA (≥ 15 μg/kg), respectively. Aspergillus species were the predominant species isolated, followed by Penicillium, and finally Mucor species.Among the examined samples, only few curry samples were contaminated with mycotoxins above acceptable limit. Despite this low level of contamination, this spice is used daily in the cuisine of this region of the world, and consequently, even the small amount of these heat stable toxins for a long time may cause many adverse effects. Hence, it is recommended to monitor the toxicogenous fungi contamination and level of mycotoxins in the spices.

Aspergillus flavus Growth Inhibition and Aflatoxin B1 Decontamination by Streptomyces Isolates and Their Metabolites

Aflatoxin B₁ is a potent carcinogen produced by Aspergillus flavus, mainly during grain storage. As pre-harvest methods are insufficient to avoid mycotoxin presence during storage, diverse curative techniques are being investigated for the inhibition of fungal growth and aflatoxin detoxification. Streptomyces spp. represent an alternative as they are a promising source of detoxifying enzymes. Fifty-nine Streptomyces isolates and a Streptomyces griseoviridis strain from the commercial product Mycostop^®, evaluated against Penicillium verrucosum and ochratoxin A during previous work, were screened for their ability to inhibit Aspergillus flavus growth and decrease the aflatoxin amount. The activities of bacterial cells and cell-free extracts (CFEs) from liquid cultures were also evaluated. Fifty-eight isolates were able to inhibit fungal growth during dual culture assays, with a maximal reduction going down to 13% of the control. Aflatoxin-specific production was decreased by all isolates to at least 54% of the control. CFEs were less effective in decreasing fungal growth (down to 40% and 55% for unheated and heated CFEs, respectively) and aflatoxin-specific production, with a few CFEs causing an overproduction of mycotoxins. Nearly all Streptomyces isolates were able to degrade AFB₁ when growing in solid and liquid media. A total degradation of AFB₁ was achieved by Mycostop^® on solid medium, as well as an almost complete degradation by IX20 in liquid medium (6% of the control). CFE maximal degradation went down to 37% of the control for isolate IX09. The search for degradation by-products indicated the presence of a few unknown molecules. The evaluation of residual toxicity of the tested isolates by the SOS chromotest indicated a detoxification of at least 68% of AFB₁’s genotoxicity.

A Review on Mycotoxins and Microfungi in Spices in the Light of the Last Five Years

Spices are imported worldwide mainly from developing countries with tropical and/or subtropical climate. Local conditions, such as high temperature, heavy rainfall, and humidity, promote fungal growth leading to increased occurrence of mycotoxins in spices. Moreover, the lack of good agricultural practice (GAP), good manufacturing practice (GMP), and good hygienic practice (GHP) in developing countries are of great concern. This review summarizes recent data from a total of 56 original papers dealing with mycotoxins and microfungi in various spices in the last five years. A total of 38 kinds of spices, 17 mycotoxins, and 14 microfungi are discussed in the review. Worldwide, spices are rather overlooked in terms of mycotoxin regulations, which usually only cover aflatoxins (AFs) and ochratoxin A (OTA). In this paper, an extensive attention is devoted to the limits on mycotoxins in spices in the context of the European Union (EU) as well as other countries. As proven in this review, the incidence of AFs and OTA, as well as other mycotoxins, is relatively high in many spices; thus, the preparation of new regulation limits is advisable.

Detection of Aflatoxin and Ochratoxin A in Spices by High-Performance Liquid Chromatography

Background. Spices are one of the flavoring components of food in the cooking recipes of different nations that are used daily. However, these ingredients may be contaminated by toxicogenic fungi and subsequent production of mycotoxins that cannot be neutralized through cooking. In the present study, the possible contamination of spices by aflatoxins (AFs) and ochratoxin A (OTA) was investigated from Shiraz, the south part of Iran. Materials and Methods. A total of 80 spice samples including turmeric (n = 20), red pepper (n = 20), black pepper (n = 20), and cinnamon (n = 20) were purchased from markets and cultured on appropriate medium. The isolated fungi were identified. Simultaneously, mycotoxins from spices were extracted with immunoaffinity columns (IAC) and the occurrence of AFs (B1 + B2 + G1 + G2) and OTA was then determined using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). Result. The results depicted that 40 spice samples were contaminated with AFs and 48 samples with OTA. The highest rate of AFs contamination was related to red pepper, in 80% of which the amount of contamination was excessive than the standard level (>10 μg/kg). All black pepper samples were determined to be contaminated with OTA at over legislation limits of >15 μg/kg. Aspergillus species were the predominant isolated fungi, followed by Penicillium, and Mucor species. Discussion. Regarding the high mycotoxins contamination in spices in the current study, regular effective surveillance and quality control procedures are highly recommended. To achieve this goal, it is necessary to empower food-related laboratories with precise methods of isolation and detection of mycotoxins.

Detection of mycobiota, aflatoxigenic and ochratoxigenic genes, and cytotoxic ability in spices

Spices are portions of plants because their properties are used as colorants, preservatives, or medicine. The employments of spices have been known since long time, and the interest in the capability of spices is astounding because of the chemical compounds contained in spices. The molds grow on a variety of different crops and foodstuffs including spices often under warm and humid conditions. The mycobiota of five spice species were surveyed. Forty-six fungal species were obtained. Aspergillus flavus and A. niger were the prevalent species recorded. The aflatoxins (AFs) and ochratoxins (OTs) were detected in some samples and isolates. Cumin had the highest concentration of AFs 8.2 ppb, while ginger had a considerable occurrence of OTs 6.7 ppb. A. flavus obtained from ginger recorded the maximum concentration of AFs 7.5 ppb, and A. niger from turmeric was the highest producer for OTs 3.6 ppb. omt-A and Aopks genes were detected in all tested A. flavus isolates and two out of four A. niger isolates. One of the important properties of spices is cancer etiology and prevention. Ginger and sage were the highest cytotoxic against four human tumor cell lines.

Toxigenic fungi and mycotoxin occurrence and prevention in food and feed in northern Africa – a review

North African countries (Algeria, Morocco and Tunisia) are surrounded by water bodies, such as the Mediterranean Sea and the Atlantic Ocean. Their climate is characterised by high temperatures and high relative humidity in some areas, which are environmental conditions favourable to fast fungal growth and toxinogenesis. This paper reports information on the presence of toxigenic fungi, mycotoxins (especially aflatoxins and ochratoxin A) and emerging Fusarium mycotoxins (enniatins, beauvericin and fusaproliferin) in some Northern African commodities that are largely consumed and were investigated thoroughly, especially raw cereals, bread, couscous, pasta, milk, spices, wine, beer, fruit juices, olives and olive oil, dried fruits and nuts, poultry feeds, etc. in the three North African countries. High contamination levels have been reported for some food samples from the three countries. Steps towards better prevention of mycotoxin production in feeds and decrease of intestinal absorption, by means of plant essential oils associated with clay, have been undertaken. Morocco presumably is the country where mycotoxin regulation is the most detailed in comparison with Algeria and Tunisia. Finally, the conclusion section offers some prospects and recommendations for actions by authorities and scientists during the monitoring of mycotoxins in the foods and feeds produced and/or commercialised in the three countries.

Aflatoxin B1 degradation by salt tolerant Tetragenococcus halophilus CGMCC 3792

This study explores aflatoxin B1 (AFB1) degradation by salt tolerant Tetragenococcus halophilus CGMCC 3792 (T. halophilus CGMCC 3792). Six non-toxic degradation products of AFB1 were identified by liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS), including m/z 243.06 (C14H10O4), 361.09 (C18H16O8), 229.09 (C14H12O3), 277.14 (C16H20O4), 217.12 (C14H16O2), 221.15 (C14H20O2). Two pathways were proposed based on molecular formulas and MS/MS spectra, and the final degradation product was m/z 221.15 (C14H20O2). The degradation ratio of active cell component (66%) and intracellular component (57%) was significantly higher than extracellular component (14%). AFB1 degradation ratio of intracellular component, initially at around 60%, was decreased to 32% after proteinase K treatment, and to 7% after heating, to 9% after proteinase K plus SDS treatment, and to 16% after TFA treatment. It suggests that the AFB1 removal mainly resulted from enzyme biodegradation. The degradation ratio was 92% in AFB1 polluted soy sauce mash. The high degradation ratio of AFB1 by T. halophilus CGMCC 3792 indicates its great potential for application in oriental fermentation condiment process.

Mold infestation and aflatoxins production in traditionally processed spices and aromatic herbs powder mostly used in West Africa

Mold infestation and occurrence of aflatoxins were investigated in 66 samples of dried spices and aromatic herbs powder (SAH) as commercialized in Benin and its neighboring countries. The samples were randomly collected from markets, supermarkets, and processing sites. Mold counts were enumerated according to standard method and aflatoxins levels were assessed using high-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). The results revealed that mold counts of samples ranged between 2.62 and 4.34 LogCFU/g. Aflatoxin B1 contents were between 0.46 μg/kg and 84.84 μg/kg with 40% of samples exceeding the recommended limit of 5 μg/kg. Aflatoxins G1 and G2 levels were low in general with means values varying from 0.24 to 8.56 μg/kg, and 0.11 to 3.68 μg/kg, respectively. Fifty-two percent (52%) of samples analyzed contained total aflatoxins levels lower than the stipulated limit of 10 μg/kg, whereas 92% of them were contaminated at various levels with one type aflatoxin, B1 or B2, G1 or G2. This study provides the first information about the occurrence of aflatoxins in the common spices used in West Africa.

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.

M. R, J. A, Mudili V, Poda S. Development of a FRET-based fluorescence aptasensor for the detection of aflatoxin B1 in contaminated food grain samples

The present study aimed to develop an aptamer-based FRET detection strategy for the specific and sensitive detection of AFB1 in contaminated food grains.