Abstract Aflatoxins Research Articles

Aflatoxin and molecular characterization of isolates from stored food in some selected Local Government in Ekiti State

Aflatoxins are secondary metabolites produced by fungi species from the genus Aspergillus, notably A. flavus, A. parasiticus and A. nomius, which develop naturally in food products and tend to cause wide array of toxic effects in several animal species, including humans. Aflatoxins are typically reported in dry food commodities such as cereals, spices, and dry fruits. This research was conducted in Ido-Osi, Efon, and Emure Local Government Areas in Ekiti State, Nigeria. Three samples; Local rice (Oryza sativa L), Maize (Zea mays) and Groundnut (Arachis hypogaea L) were obtained from three popular markets from each local government. About 10 grains of each sample were selected at random into separate petri plates and surface sterilized in 1% hypochlorite for 3 minutes. The grains were rinsed several times with distilled water. The organisms associated with the samples were isolated using Direct plating method while the aflatoxin content was determined using ELIZA. The result showed the occurrence of five (5) different fungal species distributed among the stored foods. These include: Aspergillus spp., Rhizopus spp. Penicillium spp. Mucor spp. and Botrytis spp. The species determination was confirmed by PCR with the primers specific for the ITS-rDNA region sequencing. The organisms were confirmed to the species level to be; Aspergillus flavus and Trichoderma viridie. Aflatoxin B1 was present in all the samples in which sample 6 has the highest values of 240ppb while aflatoxin B2 was relatively low. The prevalence of Aspergillus flavus in the stored foods is above 50%, which is very high and indicate the possible highlevel production of aflatoxin in food samples under study.

Dietary Exposure to Aflatoxins in Some Randomly Selected Foods and Cancer Risk Estimations of Cereals Consumed on a Ghanaian Market

Aflatoxins have gained so much reputation among all mycotoxins due to their notoriety in causing countless adverse health effects on humans as well as animals. It continues to be a major concern in food safety globally. In this study, total and constitutive aflatoxins levels as well as the carcinogenic risks posed by 110 food and feed samples (55 cereals, 20 nuts and oils, 18 animal feed, and 18 fruits and vegetables) collected from the Ho Central market in the Volta region, Ghana, were assessed. Using high-performance liquid chromatography connected to a fluorescent detector (HPLC-FLD), levels of total aflatoxins (AFtotal) and aflatoxins constituents, namely, AFB1, AFB2, AFG1, and AFG2, were analyzed. By using the model prescribed by Joint FAO/WHO Expert Committee on Food Additives (JECFA), the risks posed by the food and feed samples were determined. The degrees of toxicity were in the ranges of 0.78–234.73 μg/kg, 0.47–21.6 μg/kg, 1.01–13.75 μg/kg, and 0.66–5.51 μg/kg, respectively, for AFB1, AFB2, AFG1, and AFG2. Out of the samples analyzed for AFtotal, about 51 (46.4%) exceeded the limits of GSA and were in the range 10.63 ± 1.20–236.28 ± 4.2 μg/kg. While for EFSA, 71 (64.54%) exceeded and ranged between 4.72 ± 0.28 and 236.28 ± 4.2 μg/kg. Furthermore, estimated daily intake (EDI) of 27.10–283.70 ng/kg·bw/day, margin of exposure (MOE) of 1.409–14.76, average potency of 0–0.00396 ng aflatoxins/kg·bw/day, and cancer risks with a range of 0.107–1.122 cases/100,000 person/yr were observed. Taken together, it could be concluded that consuming cereals pose adverse effects on human health regardless of the age of the consumer.

Review on Public Health Effects of Aflatoxins in Milk and Milk-Based Foodstuffs of Dairy Cow

Aflatoxins are toxigenic metabolites that are definitely occurring by lethal strains of Aspergillus parasiticus and Aspergillus flavus that commonly dwell and colonize in feed components and various nutritive foodstuffs particularly milk and milk based products. This Review has three main objectives; those are causes of aflatoxin, effects and methods of control in milk and milk products. Drinking of cow milk polluted with aflatoxin may overwhelm immunity and subsidize to stunting in young children, as the young children are not immune-competent during early stage. It has been internationally assessed that aflatoxin is possibly accountable for 30% of the annual cases of liver cancer. Generally, control approaches of aflatoxin can be applied during pre-harvest, cautious management in the time of harvest and postharvest decontamination. Moreover, choosing breed for aflatoxin impervious crop diversities, prevention of aflatoxin production through biological decontamination by microorganisms and their metabolites, rejection of aflatoxin by physical means in addition to inactivation by chemicals are the typical approaches that have been described in different studies. For the reason that cow milk is the most important and principal diet of children, but the risk of exposed to the cancer are more in infants. In addition, according to various investigations it also well thought that young animals are also found to be more vulnerable to aflatoxin than adults. Thus; the contamination of cow milk and milk products by AFM1 should understood as undesirable for young human and animals.

Formation of B- and M-group aflatoxins and precursors by Aspergillus flavus on maize and its implication for food safety

Aflatoxins count to the most toxic known mycotoxins and are a threat to food safety especially in regions with a warm and humid climate. Contaminated food reaches consumers globally due to international trade, leading to stringent regulatory limits of aflatoxins in food. While the formation of aflatoxin (AF) B1 by the filamentous fungus Aspergillus flavus is well investigated, less is known about the formation kinetics of its precursors and further aflatoxins. In this study, autoclaved maize kernels were inoculated with A. flavus and incubated at 25 °C for up to 10 days. Aflatoxins and precursors were analyzed by a validated UHPLC-MS method. Additional to AFB1 and AFB2, AFM1 and AFM2 were detected, confirming the ability of the formation of M-group aflatoxins on cereals by A. flavus. The measured relative levels of AFB2, AFM1, and AFM2 on maize compared to the level of AFB1 (mean of days 5, 7, and 10 of incubation) were 3.3%, 1.5%, and 0.2%, respectively. The occurrence and kinetics of the measured aflatoxins and their precursors sterigmatocystin, O-methylsterigmatocystin, 11-hydroxy-O-methylsterigmatocystin, aspertoxin, and 11-hydroxyaspertoxin (group 1) as well as of dihydrosterigmatocystin and dihydro-O-methylsterigmatocystin (group 2) supported the so far postulated biosynthetic pathway. Remarkable high levels of O-methylsterigmatocystin and aspertoxin (17.4% and 4.9% compared to AFB1) were found, raising the question about the toxicological relevance of these intermediates. In conclusion, based on the study results, the monitoring of O-methylsterigmatocystin and aspertoxin as well as M-group aflatoxins in food is recommended.

Aflatoxin B1 in imported cinnamon consumed in the Yazd province of Iran

ABSTRACT Aflatoxins are toxic secondary metabolites produced mainly by Aspergillus flavus and A. parasiticus, which are fungal contaminants found in several foodstuffs, including spices. In this study 40 cinnamon samples were collected in November and December 2020 in the Iranian province of Yazd and analysed for the presence of aflatoxin B1 (AFB1) by high performance liquid chromatography. Seven out of 40 (17.5%) samples were contaminated with AFB1 at levels ranging from 0.59 to 5.8 μg/kg. In addition, 2.5% of cinnamon samples contained AFB1 concentrations above the maximum level of 5 μg/kg, as established by the Iranian national standard. Due to the harmful effects of aflatoxins, even at low amounts, these can cause serious chronic health problems. Therefore, continuous control to avoid AFB1 contamination in foodstuffs is required.

RESEARCH OF ADSORPTION AFLATOXINS BY TECHNICAL LIGNIN

Aflatoxins represent aggressive group of mycotoxins. They are really toxic, carcinogenic and dangerous for human health. There are mechanical, physical and chemical methods for their detoxification. Aflatoxins could be also neutralized by means of various adsorbents as well. We do some research work in the direction of aflatoxin adsorption by presence of lignin, which is quite affordable and gives an effective result.

An in Vitro Antifungal and Antiaflatoxigenic Properties of Commiphora myrrha and Prunus mahaleb

Aflatoxins and especially aflatoxin B, are the devastating contaminant of food and feed products with hazardous effects to mankind and his domestic animals. These investigations were set to evaluate the effect of various levels of Commiphora myrrha resin (1.0, 1.25, 2.25, and 3.25 g/100 ml) and Prunus mahaleb seed extract (0.75, 1.5, 2.5, and 3.5 g/100 ml) on the growth and aflatoxin secretion by two aflatoxigenic strains of Aspergillus flavus and A. parasiticus. The two plant extracts significantly (p<0.05) decreased aflatoxin secretion, and inhibited the fungal growth. Resin of C. myrrha displayed 51.9-95.7% reduction in total aflatoxin secretion by A. flavus, and 46.9-92% for A. parasiticus, and Seed extract of P. mahaleb decreased aflatoxin up to 53.7-95.8% and 40-94.7%, respectively. The inhibition of aflatoxin B (B1 and B2) by myrrh resin and seed extract of mahaleb ranged between 51.7-93.5, 50-93.6% (A. flavus) and 39.5-89.7%, 37.9-93% (A. parasiticus). The mycelial dry weight of A. flavus and A. parasiticus ws decreased up to 46.1-58.7%, 28.9-51.3% (Myrrh resin), and between 45-56.9%, 33.3-55.9% (Mahaleb seed extract). Nonetheless, the two plant extracts did not detoxify aflatoxin B1. Therefore, it apparent that the resin of C. myrrha and seed extract of P. mahaleb affected the biosynthesis pathway of aflatoxins. Thus, they can be recommended as effective natural plant biopreservative against aflatoxin contamination of food and feed products.

Aflatoxicosis in dogs

Aflatoxins are toxic, naturally occurring bisfuranocoumarin compounds produced by certain strains of the moulds Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxin metabolites cause hepatotoxicity by reacting with macromolecules (including DNA and proteins) to cause fatty liver or liver necrosis. Most cases involve dog food or, less commonly, ingestion of mouldy bread. Periodic outbreaks are reported in dogs, most recently at the end of 2020 to early 2021 in the US. Multiple dogs may be involved in incidents and the dogs usually present with gastrointestinal signs, lethargy, melaena and jaundice. Diagnosis is based on a history of possible ingestion and laboratory confirmation of aflatoxin(s) in suspect material. In the liver the typical histological changes are centrilobular necrosis of the liver and bile duct proliferation. Treatment of aflatoxicosis in dogs in supportive, with management of liver failure. Prognosis depends on the severity of liver damage, but mortality rates in dogs with aflatoxicosis are high.

Determining future aflatoxin contamination risk scenarios for corn in Southern Georgia, USA using spatio-temporal modelling and future climate simulations

Aflatoxins (AFs) are produced by fungi in crops and can cause liver cancer. Permitted levels are legislated and batches of grain are rejected based on average concentrations. Corn grown in Southern Georgia (GA), USA, which experiences drought during the mid-silk growth period in June, is particularly susceptible to infection by Aspergillus section Flavi species which produce AFs. Previous studies showed strong association between AFs and June weather. Risk factors were developed: June maximum temperatures > 33 °C and June rainfall < 50 mm, the 30-year normals for the region. Future climate data were estimated for each year (2000–2100) and county in southern GA using the RCP 4.5 and RCP 8.5 emissions scenarios. The number of counties with June maximum temperatures > 33 °C and rainfall < 50 mm increased and then plateaued for both emissions scenarios. The percentage of years thresholds were exceeded was greater for RCP 8.5 than RCP 4.5. The spatial distribution of high-risk counties changed over time. Results suggest corn growth distribution should be changed or adaptation strategies employed like planting resistant varieties, irrigating and planting earlier. There were significantly more counties exceeding thresholds in 2010–2040 compared to 2000–2030 suggesting that adaptation strategies should be employed as soon as possible.

A survey on the occurrence of aflatoxin M1 in raw milk samples in Bafq and Bahabad, Iran

Aflatoxins are a group of mycotoxins mostly produced by the fungi called Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomium. Aflatoxin M1 (AFM1) is the major metabolite of aflatoxin B1 and is a hepatotoxic and carcinogenic toxin. The aim of this study was to determine the level of contamination of cow's milk with aflatoxin M1 in Bafq and Bahabad. For this study, samples of raw cow's milk were collected randomly from milk collection centers around the city of Bafq and Bahabad from March to April. The determination of aflatoxin M1 levels was based on the ELISA method. Contamination was observed in 100% of milk samples. According to the results of the study, the rate of contamination with aflatoxin M1 in 43.3% of milk samples was above the acceptable level (50 ng/L) in Iranian national standard. It is concluded that further monitoring of milk production should be carried out in the spring and winter seasons.

Simultaneous Estimation of Aflatoxins (B1, B2, G1 and G2) by Liquid Chromatography Coupled with Mass Spectrometry (LC-MS) in Corn Samples

Aflatoxins produced by Aspergillus flavins and Aspergillus pasasiticus have been investigated in the corn (maize) collected in different locations in Andhra Pradesh state, India. In the present study, 24 corn samples collected from different harvest, storage and dumping areas were analyzed for detection of aflatoxin contamination by liquid chromatography coupled with mass spectrometry (LC-MS). Mixed aflatoxin working standard solutions with a concentration of 10, 20, 30, 40, 50 and 60 ng/mL were prepared and followed by instrumental analysis and the retention times of the sample chromatograms were compared with the standard aflatoxins B1, B2, G1 and G2 retention times in order to determine the contamination. The findings revealed that among 24 collected samples, only 10 samples have been found positive for aflatoxins contamination when subjected to LC-MS analysis. Co-occurrence of aflatoxin was identified in the most of the samples. Even though 10 samples were tested positive total aflatoxin content in the most positive are found within the acceptable limits (30 μg/kg) and samples collected at dumping areas (S4, S8 and S10) show the presence of exceeding quantity than the limits described by FSSAI. Total aflatoxin content in the most positive were found within the acceptable limits (30 μg/kg) and the samples collected at dumping areas S4 (40.9 μg/kg), S8 (53.2 μg/kg) and S10 (71.86 μg/kg) had shown exceeding limits. The sample S7 collected from the storage was also found positive of presence of aflatoxin G2- 13.49 μg/kg and B2-21.14 μg/kg with total aflatoxin of 34.65 μg/kg. High contamination of these dumping areas may lead to contamination of storage points nearer to these areas. Present results showed that the corn samples at dumping areas were found to be contaminated with the Aspergillus flavins and Aspergillus pasasiticus.

Türkiye’de Isparta İlinin Eğirdir Bölgesinden Toplanan Koyun Sütlerinde Aflatoksin M1 Kalıntı Varlığının ELISA ile Değerlendirilmesi

Aflatoksinler yem ve gıda ürünlerinde yaygın bir şekilde görülebilmekte ve kalıntısı ihtiva eden ürünlerin tüketiciler tarafından alınması ise önemli sağlık sorunları meydana getirmektedir. Bu çalışmada; Eğirdir’de koyun yetiştiriciliği yapılan işletmelerden toplanan 86 çiğ koyun sütü örneği aflatoksin M1 kalıntı varlığı açısından ELISA yöntemiyle analiz edildi. Analiz neticesinde 83 örneğin aflatoksin M1 kalıntısı içermediği ve 3 örneğin ise maksimum kalıntı limitinin altında kalıntı içerdiği belirlendi. Sonuç olarak, araştırılan süt örneklerinde düşük düzeyde aflatoksin M1 kalıntısının olması tüketime sunulan sütlerin tüketici sağlığı açısından bir sakınca oluşturmadığını göstermiştir.

Determinants of aflatoxin exposures in Kenyan School-aged children

ABSTRACT Aflatoxins are naturally occurring food toxins known to contaminate cereals with a carry-over effect in milk and meat products from farm animals raised on contaminated feed. In children, continuous consumption of aflatoxin-contaminated food is linked to immune suppression, vaccine interference and growth faltering while in adult populations, carcinogenesis in the liver has been established. We evaluate the main determinants of aflatoxin exposures among children recruited from primary schools in Makueni and Siaya Counties. A five-part questionnaire was administered to collect information from randomly selected participants. AflatoxinB1-lysine adducts in children’s sera and total aflatoxins in food samples were analyzed by High-Performance Liquid Chromatography with Fluorescence detection. Using Chi-squared tests and Kruskal–Wallis tests, children from low-income households had the highest aflatoxin exposure, p-value = 0.0029. Smaller family size, greater food diversity, and good farming practices were associated with low aflatoxin exposures p < 0.001. Individual households living under severe levels of poverty were evidently exposed to higher levels of aflatoxins.

Aflatoxins: A Brief Review of their Chemical Properties, Toxicological Effects and Control Measures

Aflatoxins are toxic secondary metabolites produced by the fungi of the genus Aspergillus. These substances cause food poisoning with clinical manifestations that vary according to the time of exposure and concentration of the dose ingested, representing a serious public health problem for compromising the food security, also causing considerable economic losses both in the production of stocked vegetable foods, as well as in the livestock contaminated with these substances through the feed. Therefore, this literature review aims to introduce some aspects related to the contamination of food by the fungi of the genus Aspergillus, the chemical and toxicological properties of the aflatoxins, as well as the strategies of control to avoid them in food.

Assessment of Cereals for Fungal Contaminants and Presence of Aflatoxins from Two Major Markets in Kaduna Metropolis

Aflatoxins are mycotoxins produced by fungi of the genus Aspergillus that contaminate food products such as cereals leading to serious health and economic consequences. In order to assess the level of fungal contaminants and the presence of aflatoxins in such products, five (5) different cereal samples comprising of rice, maize, millet, wheat and sorghum were purchased each from two major markets within Kaduna metropolis. The samples were assessed for fungal contaminants using ten-fold serial dilution and cultured appropriate dilutions using pour-plate technique. Aflatoxins were detected using Enzyme-linked Immunosorbent Assay (ELISA). The results obtained revealed viable fungal counts ranging from 3 x 102 to 3.2 x 103 cfu/g. The fungal contaminants identified from the samples include Aspergillus flavus, Aspergillus niger, and Aspergillus fumigatus. The aflatoxins detected from the samples were within the range of 0.3 to 0.6 part per billion (ppb) which is less than the maximum value (10ppb) recommended by regulatory agencies such as NAFDAC. This indicates that the level of aflatoxin in the samples has insignificant risks to consumers. However, the fungal contamination is an indication of high-level contamination of the cereals, the key producers of aflatoxins. The contamination of such products by fungi should be a source of worry and necessitates the need for proper personal and environmental hygiene in the processing of cereals.

Inhibitory effect of Capsicum chinense and Piper nigrum fruits, capsaicin and piperine on aflatoxins production in Aspergillus parasiticus by downregulating the expression of aflD, aflM, aflR, and aflS genes of aflatoxins biosynthetic pathway

Aflatoxins produced by Aspergillus parasiticus are toxic and carcinogenic metabolites. The biosynthesis of this mycotoxins is a complex process and involves at least 30 genes clustered within an approximately 82 kB gene cluster. In the present study, the effect of Capsicum chinense and Piper nigrum fruits on Aspergillus parasiticus growth and aflatoxin production were studied in relation to the expression of aflD, aflM, aflR, and aflS four; key genes of aflatoxins biosynthesis pathway. GC-EIMS analysis identified capsaicin (66,107 µg g−1) and piperine (1,138 µg g−1) as the most abundant compounds in C. chinense and P. nigrum fruits, respectively. The antifungal and anti-aflatoxigenic assays showed that C. chinense, P. nigrum, capsaicin, and piperine inhibited A. parasiticus growth and aflatoxins production in a dose-dependent manner. The piperine at 300 µg mL−1 produced higher radial growth inhibition (89%) and aflatoxin production inhibition (69%). The expression of aflatoxin biosynthetic genes was evaluated by quantitative real-time PCR (qRT-PCR) and revealed that aflatoxin inhibition occurring via downregulating the aflS and aflR, and subsequently aflD and aflM genes. These results will improve our understanding of the mechanism of aflatoxin regulation by C. chinense, P. nigrum, capsaicin, and piperine, and provides a reference for further study.

Aflatoxin Binders in Foods for Human Consumption-Can This be Promoted Safely and Ethically?

Aflatoxins continue to be a food safety problem globally, especially in developing regions. A significant amount of effort and resources have been invested in an attempt to control aflatoxins. However, these efforts have not substantially decreased the prevalence nor the dietary exposure to aflatoxins in developing countries. One approach to aflatoxin control is the use of binding agents in foods, and lactic acid bacteria (LAB) have been studied extensively for this purpose. However, when assessing the results comprehensively and reviewing the practicality and ethics of use, risks are evident, and concerns arise. In conclusion, our review suggests that there are too many issues with using LAB for aflatoxin binding for it to be safely promoted. Arguably, using binders in human food might even worsen food safety in the longer term.

Detection of Total Aflatoxins in Groundnut and Soybean Samples in Yemen Using Enzyme-Linked Immunosorbent Assay

Aflatoxins are fungal toxins that have mutagenic and carcinogenic effects, especially hepatocellular carcinoma effect. This work aimed to investigate the presence of aflatoxins in groundnuts and soybeans that are consumed in Yemen. The samples were collected from three different regions in Yemen (Sana’a, al-Hodeida, and Aden), and they were divided into two groups. The concentration of total aflatoxins was analyzed by enzyme-linked immunosorbent assay (ELISA). Aflatoxins were determined in 89 groundnut and 65 soybean samples. The results showed that 85.39% (76/89) of groundnut and 72.3% (45/65) of soybean samples were contaminated with aflatoxins. In addition, in 49.44% and 27.6% of the groundnut and soybean samples, total aflatoxins exceed the acceptable level of European Commission (4 μg/kg), while in only 6.2% of soybean samples and 22.47% of groundnut samples, total aflatoxins were beyond the maximum limit of FDA/Yemen standards (20 μg/kg). The results showed that the aflatoxin contamination in the groundnut and soybean samples may be considered a significant risk for public health. The present study is the first to report the data on the presence of aflatoxins in groundnut and soybean samples in Yemen.

Metal Ions in Activated Carbon Improve the Detection Efficiency of Aflatoxin-Producing Fungi.

Aflatoxins (AF), produced by several Aspergillus species, are visible under ultraviolet light if present in high amounts. AF detection can be improved by adding activated carbon, which enhances the observation efficiency of weakly AF-producing fungi. However, commercial activated carbon products differ in their characteristics, making it necessary to investigate which characteristics affect method reproducibility. Herein, the addition of 10 activated carbon products resulted in different AF production rates in each case. The differences in the production of aflatoxin G1 (AFG1) were roughly correlated to the observation efficiency in the plate culture. Trace element analysis showed that the concentrations of several metal ions differed by factors of >100, and the carbons that most effectively increased AFG1 production contained higher amounts of metal ions. Adding 5 mg L−1 Fe or Mg ions increased AFG1 production even without activated carbon. Furthermore, co-addition of both ions increased AFG1 production stably with the addition of carbon. When varying the concentration of additives, only AFG1 production increased in a concentration-dependent manner, while the production of all the other AFs decreased or remained unchanged. These findings suggest that a key factor influencing AF production is the concentration of several metal ions in activated carbon and that increasing AFG1 production improves AF detectability.

A survey of AFM1 contamination in row cow milk produced in region of Kumanovo

Aflatoxins (AFs) are type of mycotoxins produced by certain Aspergillus species. In the livers of cows, the aflatoxin В1 (AFB1) ingested with contaminated food is metabolized in carcinogenic aflatoxin М1 (AFM1) which is then excreted in the milk and poses a serious risk to the health of the consumers. In January of 2019, twenty five (25) samples of milk were collected from local farms in the surrounding area of Kumanovo, Republic of North Macedonia. The samples were analysed in the Centre for Public Health, Kumanovo. A method MKC EN ISO 14501:2007 for analysis of AFM1 by HPLC with fluorescence detection was applied. This method is selective, precise and applicative. The final analytical result has shown AFM1 below the LOD in any of the analyzed samples. Due to the well-known fact that AFM1 is toxic, i.e. carcinogenic and the fact that milk is widely used as staple food, continuous development as well as introduction of new, more sensitive methods for detection of AFM1 are required. Keywords: Aflatoxin M1, HPLC-FLD, milk