Novel Sensor Approaches of Aflatoxins Determination in Food and Beverage Samples

The rapid quantification of toxins in food and beverage products has become a significant issue in overcoming and preventing many life-threatening diseases. Aflatoxin-contaminated food is one of the reasons for primary liver cancer and induces some tumors and cancer types. Advancements in biosensors technology have brought out different analysis methods. Therefore, the sensing performance has been improved for agricultural and beverage industries or food control processes. Nanomaterials are widely used for the enhancement of sensing performance. The enzymes, molecularly imprinted polymers (MIP), antibodies, and aptamers can be used as biorecognition elements. The transducer part of the biosensor can be selected, such as optical, electrochemical, and mass-based. This review explains the classification of major types of aflatoxins, the importance of nanomaterials, electrochemical, optical biosensors, and QCM and their applications for the determination of aflatoxins.

Prevalence and concentration of aflatoxin M1 in breast milk in Africa: a meta-analysis and implication for the interface of agriculture and health

Breast milk is one of the many distinct forms of food that can be contaminated with aflatoxin M1 (AFM1). They may be consumed by eating contaminated foods, such as contaminated meat and crops, which would then be present in breast milk and cause health problems, including nervous system disorders and cancers of the lungs, liver, kidneys, and urinary tract. However, the prevalently inconsistent explanation of prevalence and concentration remains a big challenge. Thus, this meta-analysis was conducted to determine the prevalence and concentration of harmful chemicals in breast milk in an African context. The databases MEDLINE, PubMed, Embase, SCOPUS, Web of Science, and Google Scholar were searched for both published and unpublished research. To conduct the analysis, the collected data were exported to Stata version 18. The results were shown using a forest plot and a prevalence with a 95% confidence interval (CI) using the random-effects model. The Cochrane chi-square (I2) statistics were used to measure the studies' heterogeneity, and Egger's intercept was used to measure publication bias. This review included twenty-eight studies with 4016 breast milk samples and newborns. The analysis showed the overall prevalence and concentration of aflatoxin M1 in breast milk were 53% (95% CI 40, 65; i2 = 98.26%; P = 0.001). The pooled mean aflatoxin M1 concentration in breast milk was 93.02 ng/l. According to this study, the eastern region of Africa was 62% (95% CI 39-82) profoundly affected as compared to other regions of the continent. In subgroup analysis by publication year, the highest level of exposure to aflatoxins (68%; 95% CI 47-85) was observed among studies published from 2010 to 2019. This finding confirmed that more than half of lactating women's breast milk was contaminated with aflatoxin M1 in Africa. The pooled mean aflatoxin M1 concentration in breast milk was 93.02 ng/l. According to this study, the eastern region of Africa was profoundly affected compared with other regions. Thus, the government and all stakeholders must instigate policies that mitigate the toxicity of aflatoxins in lactating women, fetuses, and newborns.

The occurrence and human health risk assessment of total and aflatoxin B1 in selected food commodities in Bhutan

Aflatoxins are mycotoxins that contaminate staple foods globally and pose a significant health risk. To the best of our knowledge, information on the occurrence of aflatoxins in Bhutanese diets is scarce. This study aimed to estimate the aflatoxin levels in selected foodstuffs in Bhutan and determine the health risk associated with aflatoxin exposure. Ten different types of food commodities were randomly collected from farmers' markets, shelves of supermarkets, and wholesale and retail shops from 20 districts of the country. The samples were subjected to analysis by an enzyme-linked immunosorbent assay for both total aflatoxins (B1, B2, G1 and G2) and aflatoxin B1. Among the 315 samples included, 48.81% and 79.35% were positive for total aflatoxins and aflatoxin B1, respectively. The overall mean total aflatoxin concentration was 11.49 ± 12.83 µg/kg, and that for B1 was 17.62 ± 23.99 µg/kg. The most prevalent food commodity with the highest aflatoxin contamination was chili products. In addition, the estimated daily intake and margin of exposure to aflatoxin B1 via the consumption of chili products ranged from 0.98 to 5.34 ng kg-1 bw day-1 and from 74.90 to 408.10, indicating a risk for public health. The liver cancer risk was estimated to be 0.01 and 0.007 cancers per year per 100,000 population resulting from the consumption of chili products. The present findings revealed the presence of total aflatoxins and aflatoxin B1 in the selected samples. The margin of exposure values was exorbitant, demanding a stringent public health measure. Notably, these results suggest the need for routine monitoring of aflatoxin contamination in the region and stress rigorous safety management strategies to reduce exposure.

Aflatoxins in the rice production chain: A review on prevalence, detection, and decontamination strategies

Rice (Oryza sativa L.) is one of the most consumed cereals that along with several important nutritional constituents typically provide more than 21% of the caloric requirements of human beings. Aflatoxins (AFs) are toxic secondary metabolites of several Aspergillus species that are prevalent in cereals, including rice. This review provides a comprehensive overview on production factors, prevalence, regulations, detection methods, and decontamination strategies for AFs in the rice production chain. The prevalence of AFs in rice is more prominent in African and Asian than in European countries. Developed nations have more stringent regulations for AFs in rice than in the developing world. The contamination level of AFs in the rice varied at different stages of rice production chain and is affected by production practices, environmental conditions comprising temperature, humidity, moisture, and water activity as well as milling operations such as de-husking, parboiling, and polishing. A range of methods including chromatographic techniques, immunochemical methods, and spectrophotometric methods have been developed, and used for monitoring AFs in rice. Chromatographic methods are the most used methods of AFs detection followed by immunochemical techniques. AFs decontamination strategies adopted worldwide involve various physical, chemical, and biological strategies, and even using plant materials. In conclusion, adopting good agricultural practices, implementing efficient AFs detection methods, and developing innovative aflatoxin decontamination strategies are imperative to ensure the safety and quality of rice for consumers.

Application of Biosensors for the Detection of Mycotoxins for the Improvement of Food Safety

Mycotoxins, secondary metabolites synthesized by various filamentous fungi genera such as Aspergillus, Penicillium, Fusarium, Claviceps, and Alternaria, are potent toxic compounds. Their production is contingent upon specific environmental conditions during fungal growth. Arising as byproducts of fungal metabolic processes, mycotoxins exhibit significant toxicity, posing risks of acute or chronic health complications. Recognized as highly hazardous food contaminants, mycotoxins present a pervasive threat throughout the agricultural and food processing continuum, from plant cultivation to post-harvest stages. The imperative to adhere to principles of good agricultural and industrial practice is underscored to mitigate the risk of mycotoxin contamination in food production. In the domain of food safety, the rapid and efficient detection of mycotoxins holds paramount significance. This paper delineates conventional and commercial methodologies for mycotoxin detection in ensuring food safety, encompassing techniques like liquid chromatography, immunoassays, and test strips, with a significant emphasis on the role of electrochemiluminescence (ECL) biosensors, which are known for their high sensitivity and specificity. These are categorized into antibody-, and aptamer-based, as well as molecular imprinting methods. This paper examines the latest advancements in biosensors for mycotoxin testing, with a particular focus on their amplification strategies and operating mechanisms.

Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis

Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.

Determination and risk assessment of aflatoxin B1 in the kernel of imported raw hazelnuts from Eastern Azerbaijan Province of Iran

Aflatoxin B1 (AFB1) is widespread and seriously threatens public health worldwide. This study aimed to investigate AFB1 in imported hazelnut samples in northwest of Iran (Eastern Azerbaijan Province) using High-Performance Liquid Chromatography with a Fluorescent Detector (HPLC-FLD). In all tested samples AFB1 was detected. The mean concentration of AFB1 was 4.20 μg/kg and ranged from 3.145 to 8.13 μg/kg. All samples contained AFB1 levels within the maximum acceptable limit except for one sample. Furthermore, the human health risk assessment of AFB1 from consuming imported hazelnuts by Iranian children and adults was evaluated based on the margin of exposure (MoE) and quantitative liver cancer risk approaches. The MoE mean for children was 2529.76, while for adults, it was 8854.16, indicating a public health concern. The present study found that the risk of developing liver cancer among Iranian children was 0.11100736 per 100,000 people, and in the Iranian adult population was 0.0314496 cancers per 100,000 people. Since environmental conditions potentially affect aflatoxin levels in nuts, countries are advised to monitor aflatoxin contents in imported nuts, especially from countries with a conducive climate for mold growth.

Level of exposure to aflatoxins during pregnancy and its association with adverse birth outcomes in Africa: a meta-analysis

BACKGROUND

Aflatoxins are various poisonous carcinogens and mutagens produced by Aspergillus species. Exposure to aflatoxins during pregnancy results in adverse birth outcomes. This meta-analysis was carried out to determine the estimates of how much aflatoxin is harmful to the pregnancy and its outcome, including birthweight, birth length, low birthweight (LBW), small for gestational age (SGA), stunting, poverty, food insecurity, income, pesticides and stillbirth, in an African context.

METHODS

Both published and unpublished studies in Africa were searched on MEDLINE, PubMed, Embase, SCOPUS, Web of Science and Google Scholar. Stata version 18.2 software was used for cleaning and analysis. The prevalence with a 95% confidence interval (CI) was estimated using the random effects model and a forest plot was used to present the findings. In addition, the heterogeneity of the study was assessed using Cochrane I2 statistics and publication bias was assessed using Egger's intercept and funnel plot.

RESULTS

This review included 28 studies with a total of 6283 pregnant women and newborns. The analysis showed the overall level of exposure to aflatoxins was 64% (95% CI 48 to 78, τ2=0.66, I2=99.34%, p=0.001). In the subgroup analysis by publication year, the highest level of exposure to aflatoxins (82% [95% CI 69 to 92]) was observed among studies published from 2020 to 2023. This study also found that exposure to aflatoxins during pregnancy had an association with prematurity, LBW, SGA and stillbirth.

CONCLUSIONS

The data analysed in this study indicated that three of every five pregnant women had exposure to aflatoxins in Africa. Moreover, pregnant women exposed to aflatoxins had a higher likelihood of having a LBW and SGA newborn. Thus governments and all stakeholders should initiate policies that mitigate the toxicity of aflatoxins in pregnant women, foetuses and newborns.

Innovative approaches for mycotoxin detection in various food categories

Mycotoxins (MTs), produced by filamentous fungi, represent a severe hazard to the health of humans and food safety, affecting the quality of various agricultural products. They can contaminate a wide range of foods, during any processing phase before or after harvest. Animals and humans who consume MTs-contaminated food or feed may experience acute or chronic poisoning, which may result in serious pathological consequences. Accordingly, developing rapid, easy, and accurate methods of MTs detection in food becomes highly urgent and critical as a quality control and to guarantee food safety and lower health hazards. In this review, we highlighted and discussed innovative approaches like biosensors, fluorescent polarization, capillary electrophoresis, infrared spectroscopy, and electronic noses for MT identification pointing out current challenges and future directions. The limitations, current challenges, and future directions of conventional detection methods versus innovative methods have also been highlighted and discussed.

Aflatoxins posing threat to food safety and security in Pakistan: Call for a one health approach

Aflatoxins are among the most important mycotoxins due to their widespread occurrence and adverse impacts on humans and animals. These toxins and/or their metabolites cannot be destroyed with cooking or boiling methods. Therefore, consumption of aflatoxin-contaminated food may lead to impaired growth, compromised immunity, stomach and liver cancer, and acute toxicity. These adverse effects along with food wastage might have detrimental consequences on a country's economy. Several studies from Pakistan reported a high prevalence of aflatoxins in food and feed commodities (Range; milk = 0.6-99.4%, cereals, and grains = 0.38-41%, animal feed = 31-100%). Notably, Pakistan reported very high figures of impaired child growth-stunted 40.2%, wasted 17.7% and underweight 28.9%-that could be associated with the higher aflatoxin prevalence in food items. Importantly, high aflatoxins prevalence, i.e. 100%, 69% and 60.5%, in children has been reported in Pakistan. Food and feed are more prone to aflatoxin contamination due to Pakistan's hot and humid climate; however, limited awareness, inadequate policy framework, and weak implementation mechanisms are the major obstacles to effective control. This review will discuss aflatoxins prevalence, associated risk factors, adverse health effects, required regulatory regime, and effective control strategies adopting the One Health approach to ensure food safety and security.

Humanoid-shaped WaveFlex biosensor for the detection of food contamination

High-toxicity secondary metabolites called aflatoxin are naturally produced by the fungus Aspergillus. In a warm, humid climate, Aspergillus growth can be considerably accelerated. The most dangerous chemical among all aflatoxins is aflatoxin B1 (AFB1), which has the potential to cause cancer and several other health risks. As a result, food forensicists now urgently need a method that is more precise, quick, and practical for aflatoxin testing. The current study focuses on the development of a highly sensitive, specific, label-free, and rapid detection method for AFB1 using a novel humanoid-shaped fiber optic WaveFlex biosensor (refers to a plasmon wave-based fiber biosensor). The fiber probe has been functionalized with nanomaterials (gold nanoparticles, graphene oxide and multiwalled carbon nanotubes) and anti-AFB1 antibodies to enhance the sensitivity and specificity of the developed sensor. The findings demonstrate that the developed sensor exhibits a remarkable low detection limit of 34.5 nM and exceptional specificity towards AFB1. Furthermore, the sensor demonstrated exceptional characteristics such as high stability, selectivity, reproducibility, and reusability. These essential factors highlight the significant potential of the proposed WaveFlex biosensor for the accurate detection of AFB1 in diverse agricultural and food samples.

Aluminosilicates as a Double-Edged Sword: Adsorption of Aflatoxin B1 and Sequestration of Essential Trace Minerals in an In Vitro Gastrointestinal Poultry Model

Aflatoxins can cause intoxication and poisoning in animals and humans. Among these molecules, aflatoxin B1 (AFB1) is the most dangerous because of its carcinogenic and mutagenic properties. To mitigate these effects, clay adsorbents are commonly included in the diet of animals to adsorb the carcinogens and prevent their absorption in the gastrointestinal tract. In this study, four clays, three smectites (C-1, C-2, and C-3), and one zeolite (C-4), were compared as adsorbents of AFB1 and trace inorganic nutrients using an in vitro gastrointestinal model for poultry. Characterization of the clays using Fourier transform infrared spectroscopy revealed characteristic bands of smectites in C-1, C-2, and C-3 (stretching vibrations of Si-O, Al-O-Si, and Si-O-Si). The C-4 presented bands related to the bending vibration of structural units (Si-O-Si and Al-O-Si). X-ray diffraction analysis showed that C-1 is a montmorillonite, C-2 is a beidellite, C-3 is a beidellite-Ca-montmorillonite, and C-4 is a clinoptilolite. The elemental compositions of the clays showed alumina, silica, iron, calcium, and sodium contents. The cation exchange capacity was higher in C-3 clay (60.2 cmol(+)/kg) in contrast with the other clays. The AFB1 adsorption of C-1 was the highest (98%; p ˂ 0.001), followed by C-2 (94%). However, all the clays also sequestered trace inorganic nutrients (Fe, Mn, Zn, and Se). Both smectites, montmorillonite and beidellite, were the most suitable for use as adsorbents of AFB1.

Handheld Fluorescence Spectrometer Enabling Sensitive Aflatoxin Detection in Maize

Aflatoxins are among the main carcinogens threatening food and feed safety while imposing major detection challenges to the agrifood industry. Today, aflatoxins are typically detected using destructive and sample-based chemical analysis that are not optimally suited to sense their local presence in the food chain. Therefore, we pursued the development of a non-destructive optical sensing technique based on fluorescence spectroscopy. We present a novel compact fluorescence sensing unit, comprising both ultraviolet excitation and fluorescence detection in a single handheld device. First, the sensing unit was benchmarked against a validated research-grade fluorescence setup and demonstrated high sensitivity by spectrally separating contaminated maize powder samples with aflatoxin concentrations of 6.6 µg/kg and 11.6 µg/kg. Next, we successfully classified a batch of naturally contaminated maize kernels within three subsamples showing a total aflatoxin concentration of 0 µg/kg, 0.6 µg/kg and 1647.8 µg/kg. Consequently, our novel sensing methodology presents good sensitivity and high potential for integration along the food chain, paving the way toward improved food safety.

Research update on aflatoxins toxicity, metabolism, distribution, and detection: A concise overview

Serious health risks associated with the consumption of food products contaminated with aflatoxins (AFs) are worldwide recognized and depend predominantly on consumed AF concentration by diet. A low concentration of aflatoxins in cereals and related food commodities is unavoidable, especially in subtropic and tropic regions. Accordingly, risk assessment guidelines established by regulatory bodies in different countries help in the prevention of aflatoxin intoxication and the protection of public health. By assessing the maximal levels of aflatoxins in food products which are a potential risk to human health, it's possible to establish appropriate risk management strategies. Regarding, a few factors are crucial for making a rational risk management decision, such as toxicological profile, adequate information concerning the exposure duration, availability of routine and some novel analytical techniques, socioeconomic factors, food intake patterns, and maximal allowed levels of each aflatoxin in different food products which may be varied between countries.

Aflatoxin Contamination: An Overview on Health Issues, Detection and Management Strategies

Aflatoxins (AFs) represent one of the main mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus, with the most prevalent and lethal subtypes being AFB1, AFB2, AFG1, and AFG2. AFs are responsible for causing significant public health issues and economic concerns that affect consumers and farmers globally. Chronic exposure to AFs has been linked to liver cancer, oxidative stress, and fetal growth abnormalities among other health-related risks. Although there are various technologies, such as physical, chemical, and biological controls that have been employed to alleviate the toxic effects of AF, there is still no clearly elucidated universal method available to reduce AF levels in food and feed; the only mitigation is early detection of the toxin in the management of AF contamination. Numerous detection methods, including cultures, molecular techniques, immunochemical, electrochemical immunosensor, chromatographic, and spectroscopic means, are used to determine AF contamination in agricultural products. Recent research has shown that incorporating crops with higher resistance, such as sorghum, into animal feed can reduce the risk of AF contamination in milk and cheese. This review provides a current overview of the health-related risks of chronic dietary AF exposure, recent detection techniques, and management strategies to guide future researchers in developing better detection and management strategies for this toxin.

Dummy molecularly imprinted solid-phase extraction-SERS determination of AFB1 in peanut

As a class I carcinogen, aflatoxin B1 (AFB1) contamination in foods and feeds accounts for 75 % of the total mycotoxin contamination. In this work, a simple and reliable surface-enhanced Raman spectroscopy (SERS) method for sensitive and selective detection of AFB1 in peanut samples integrated with dummy molecularly imprinted polymers (DMIPs) is developed. N-isopropylacrylamide (NIPAM) and 7-ethoxycoumarin (7-EOC) are chosen as monomer and dummy template, respectively and their ratio was screened through molecular design in both of kinetic and static adsorption views to form the optimal DMIPs. As-prepared dummy molecularly imprinted solid-phase extraction (DMISPE) could selectively enrich AFB1 from peanut samples. Finally, a liquid-liquid interface self-assembly constructed thioctic acid-decorated AgNPs monolayer film (TA-AgNPs MF) as a SERS-active substrate is employed to determine the amount of AFB1 eluted from DMISPE. SERS assay shows high detection sensitivity for AFB1 in peanut samples with limit of detection of 0.1 μg L^-1 and a linear concentration relationship range from 0.1 to 10 μg L^-1.

Efficacy of Bentonite and Fumonisin Esterase in Mitigating the Effects of Aflatoxins and Fumonisins in Two Kenyan Cattle Breeds

The objective of the study was to investigate the efficacy of bentonite and fumonisin esterase, separately or combined, in mitigating the effects of aflatoxins (AF) and fumonisins (FUM) in Boran and Friesian-Boran crossbreed cattle. These effects were studied by measuring mycotoxins, their metabolites, and biomarkers that relate to animal health, productivity, and food safety. The study was divided into three experiments each lasting for 2 weeks. Cows in experiment 1 received in random order aflatoxin B1 (AFB1) [788 μg/cow/day (69.7 μg/kg dry matter intake (DMI)) for Borans and 2,310 μg/cow/day (154 μg/kg DMI) for crossbreeds], bentonite (60 g/cow/day), or both AFB1 and bentonite. Boran cows in experiment 2 received in random order FUM (12.4 mg/cow/day (1.1 mg/kg DMI)), fumonisin esterase (120 U/cow/day), or both FUM and fumonisin esterase. Boran cows in experiment 3 received in random order AFB1 (952 μg/cow/day (84.2 μg/kg DMI)) + FUM (30.4 mg/cow/day (2.7 mg/kg DMI)), bentonite (60 g/cow/day) + fumonisin esterase (120 U/cow/day), or both AFB1 + FUM and bentonite + fumonisin esterase. Feeding AFB1 and/or FUM contaminated feed with or without the addition of the detoxifiers for 14 days did not affect DMI, milk composition, hematology, and blood biochemical parameters. The addition of bentonite in a diet contaminated with AFB1 led to a decrease in milk aflatoxin M1 (AFM1) concentration of 30% and 43%, with the carry-over subsequently decreasing from 0.35% to 0.20% and 0.08% to 0.06% for crosses and Borans, respectively. No significant change was observed in the sphinganine/sphingosine (Sa/So) ratio following feeding with FUM alone or in combination with fumonisin esterase; however, the ability of fumonisin esterase to hydrolyze FUM into less toxic fully hydrolyzed FUM and partially hydrolyzed FUM was evident in the rumen fluid and feces. These results indicate bentonite was effective in decreasing AFM1 concentration in milk, and AFB1 and AFM1 in plasma, while fumonisin esterase can convert FUM into less toxic metabolites and can be a suitable addition to feed cocontaminated with AFB1 and FUM.

Impact of Volatile Organic Compounds on the Growth of Aspergillus flavus and Related Aflatoxin B1 Production: A Review

Volatile organic compounds (VOCs) are secondary metabolites of varied chemical nature that are emitted by living beings and participate in their interactions. In addition, some VOCs called bioactive VOCs cause changes in the metabolism of other living species that share the same environment. In recent years, knowledge on VOCs emitted by Aspergillus flavus, the main species producing aflatoxin B1 (AFB1), a highly harmful mycotoxin, has increased. This review presents an overview of all VOCs identified as a result of A. flavus toxigenic (AFB1-producing) and non-toxigenic (non AFB1-producing) strains growth on different substrates, and the factors influencing their emissions. We also included all bioactive VOCs, mixes of VOCs or volatolomes of microbial species that impact A. flavus growth and/or related AFB1 production. The modes of action of VOCs impacting the fungus development are presented. Finally, the potential applications of VOCs as biocontrol agents in the context of mycotoxin control are discussed.

May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects

The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.

Recent Progress on Techniques in the Detection of Aflatoxin B1 in Edible Oil: A Mini Review

Contamination of agricultural products and foods by aflatoxin B1 (AFB1) is becoming a serious global problem, and the presence of AFB1 in edible oil is frequent and has become inevitable, especially in underdeveloped countries and regions. As AFB1 results from a possible degradation of aflatoxins and the interaction of the resulting toxic compound with food components, it could cause chronic disease or severe cancers, increasing morbidity and mortality. Therefore, rapid and reliable detection methods are essential for checking AFB1 occurrence in foodstuffs to ensure food safety. Recently, new biosensor technologies have become a research hotspot due to their characteristics of speed and accuracy. This review describes various technologies such as chromatographic and spectroscopic techniques, ELISA techniques, and biosensing techniques, along with their advantages and weaknesses, for AFB1 control in edible oil and provides new insight into AFB1 detection for future work. Although compared with other technologies, biosensor technology involves the cross integration of multiple technologies, such as spectral technology and new nano materials, and has great potential, some challenges regarding their stability, cost, etc., need further studies.

Incidence of Aflatoxin in Ready to Eat Nuts from Local Food Markets in Mangaluru, India

Background and Objective Aflatoxins are a group of naturally occurring mycotoxin which are toxic secondary metabolites produced by certain filamentous fungi like Aspergillus flavus and Aspergillus parasiticus. The main objective of this study was to screen the occurrence of aflatoxin in ready to eat nuts available locally and analyzing for its nutritive value and to evaluate the efficiency of conventional (thin-layer chromatography [TLC]) and sensitive kit-based (enzyme-linked immunosorbent assay [ELISA]) method by detection of the aflatoxin in the sample.

Methods A total of 50 samples including peanuts (10), cashew nuts (10), almonds (10), pistachio (10), and walnuts (10) were collected from different stores in Mangalore city. Each sample was divided into three fractions, as for microbiological analysis, proximate analysis, and detection of aflatoxin by following standard method (AOAC2000).

Results The present study evidenced the contamination of aflatoxin in all of the five types of ready-to-eat nuts examined and the concentration was within the acceptable limits. But, among the samples analyzed, G10 (groundnut) showed a maximum concentration of 16 µg/L aflatoxin detected by ELISA method. It was also observed that the proximate analysis mainly moisture content did not affect aflatoxin accumulation.

Conclusion Our study shows that aflatoxin contamination of food products has become a serious threat. Although several methods for detection and quantification of toxins have been developed, due to their low concentration of toxicity in food commodities, an analytical method for detection and quantification of aflatoxin have to be specific, sensitive, and simple to carry out and among TLC and ELISA, ELISA came out as a suitable for rapid and sensitive detection.

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.

Peanut Butter Food Safety Concerns-Prevalence, Mitigation and Control of Salmonella spp., and Aflatoxins in Peanut Butter

Peanut butter has a very large and continuously increasing global market. The food safety risks associated with its consumption are also likely to have impacts on a correspondingly large global population. In terms of prevalence and potential magnitude of impact, contamination by Salmonella spp., and aflatoxins, are the major food safety risks associated with peanut butter consumption. The inherent nature of the Salmonella spp., coupled with the unique chemical composition and structure of peanut butter, present serious technical challenges when inactivating Salmonella spp. in contaminated peanut butter. Thermal treatment, microwave, radiofrequency, irradiation, and high-pressure processing all are of limited efficacy in inactivating Salmonella spp. in contaminated peanut butter. The removal of aflatoxins in contaminated peanut butter is equally problematic and for all practical purposes almost impossible at the moment. Adopting good manufacturing hygiene practices from farm to table and avoiding the processing of contaminated peanuts are probably some of the few practically viable strategies for minimising these peanut butter food safety risks. The purpose of this review is to highlight the nature of food safety risks associated with peanut butter and to discuss the effectiveness of the initiatives that are aimed at minimising these risks.

Analysis and classification of peanuts with fungal diseases based on real-time spectral processing

The study presents an approach to the analysis and classification of peanuts performed in order to detect kernels with fungi diseases, i.e. kernels prone to contamination with mycotoxigenic Aspergillus flavus (Aspergillus parasiticus). The aim of this study was to evaluate the effectiveness of luminescent spectroscopy with a violet laser (405 nm wavelength) as the excitation source of the fluorescence when applied for real-time detection of mould in peanuts performed by means of multispectral processing based on machine learning methods. We suggest a laboratory unit used to form, register, and process the luminescence spectra of peanuts in visible and near-infrared wavelength ranges in the real-time mode. The study demonstrated that contaminated peanuts have increased luminous intensity and show a redshift in the fluorescence peaks of the contaminated samples as compared to the pure ones. The difference in the fluorescence spectra of pure and contaminated kernels is compatible with the results obtained when traditional UV-light sources are used (365 nm). To classify peanuts by their spectral characteristics, neural network algorithms were used combined with dimensionality reduction methods. The paper presents the probabilities of incorrect recognition of the peanuts' type depending on the number of relevant secondary features determined when reducing the dimensionality of the initial data. When 10 spectral components were used, the error ratios were 0.7% or 0.3% depending on the method of reducing the dimensionality of the initial data.

Aflatoxin Contamination, Its Impact and Management Strategies: An Updated Review

Aflatoxin, a type of mycotoxin, is mostly produced by Aspergillus flavus and Aspergillus parasiticus. It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops such as cotton, groundnut, maize, and chilies, and causing immense effects on the health of humans and animals. More than eighteen different types of aflatoxins have been reported to date, and among them, aflatoxins B1, B2, G1, and G2 are the most prevalent and lethal. Early detection of fungal infection plays a key role in the control of aflatoxin contamination. Therefore, different methods, including culture, chromatographic techniques, and molecular assays, are used to determine aflatoxin contamination in crops and food products. Many countries have set a maximum limit of aflatoxin contamination (2-20 ppb) in their food and agriculture commodities for human or animal consumption, and the use of different methods to combat this menace is essential. Fungal infection mostly takes place during the pre- and post-harvest stage of crops, and most of the methods to control aflatoxin are employed for the latter phase. Studies have shown that if correct measures are adopted during the crop development phase, aflatoxin contamination can be reduced by a significant level. Currently, the use of bio-pesticides is the intervention employed in many countries, whereby atoxigenic strains competitively reduce the burden of toxigenic strains in the field, thereby helping to mitigate this problem. This updated review on aflatoxins sheds light on the sources of contamination, and the on occurrence, impact, detection techniques, and management strategies, with a special emphasis on bio-pesticides to control aflatoxins.

Aspergillus flavus and Total Aflatoxins Occurrence in Dairy Feed and Aflatoxin M1 in Bovine Milk in Aguascalientes, Mexico

Contamination of food chains by toxigenic fungi and aflatoxins is a global problem that causes damage to human health, as well as to crop and livestock production. The objective is to evaluate Aspergillus flavus and total aflatoxins (AFs) occurrence in totally mixed rations (TMRs) for dairy cows and aflatoxin M1 (AFM1) in milk for human consumption. Ninety-nine dairy production units located in Aguascalientes, Mexico, were randomly selected, and samples were collected from TMRs, raw milk, and milk marketed in the city in two consecutive agricultural cycles. AFs were quantified in TMRs and milk by indirect enzyme immunoassay and HPLC; aflatoxigenic and molecular (PCR) capacity of monosporic A. flavus isolates in the feed was characterized. All feed, raw, and pasteurized milk samples showed aflatoxin contamination (26.0 ± 0.4 µg/kg, 32.0 ± 1.0, and 31.3 ± 0.7 ng/L, respectively), and a significant proportion (90.4, 11.3, and 10.3%) exceeded the locally applied maximum permissible limits for feed and milk (20.0 µg/kg and 50 ng/L). Aflatoxin contamination in both TMRs and milk indicated a seasonal influence, with a higher concentration in the autumn-winter cycle when conditions of higher humidity prevail. The results obtained suggest the existence of contamination by aflatoxigenic A. flavus and aflatoxins in the diet formulated for feeding dairy cows and, consequently, in the dairy food chain of this region of the Mexican Highland Plateau.

Fluorescence spectroscopy and multispectral imaging for fingerprinting of aflatoxin-B1 contaminated (Zea mays L.) seeds: a preliminary study

Cereal seeds safety may be compromised by the presence of toxic contaminants, such as aflatoxins. Besides being carcinogenic, they have other adverse health effects on humans and animals. In this preliminary study, we used two non-invasive optical techniques, optical fiber fluorescence spectroscopy and multispectral imaging (MSI), for discrimination of maize seeds naturally contaminated with aflatoxin B₁ (AFB₁) from the uncontaminated seeds. The AFB₁-contaminated seeds exhibited a red shift of the emission maximum position compared to the control samples. Using linear discrimination analysis to analyse fluorescence data, classification accuracy of 100% was obtained to discriminate uncontaminated and AFB₁-contaminated seeds. The MSI analysis combined with a normalized canonical discriminant analysis, provided spectral and spatial patterns of the analysed seeds. The AFB₁-contaminated seeds showed a 7.9 to 9.6-fold increase in the seed reflectance in the VIS region, and 10.4 and 12.2-fold increase in the NIR spectral region, compared with the uncontaminated seeds. Thus the MSI method classified successfully contaminated from uncontaminated seeds with high accuracy. The results may have an impact on development of spectroscopic non-invasive methods for detection of AFs presence in seeds, providing valuable information for the assessment of seed adulteration in the field of food forensics and food safety.

Aflatoxin B1 in the egg chain: monitoring with specific indirect competitive ELISA in northern Paraná, Brazil

An indirect competitive immunoassay (ic-ELISA) was developed using monoclonal antibody produced by hybridoma AF4, which showed high specificity and reactivity with aflatoxin B1 (AFB1) and aflatoxicol, but low cross-reactivity to other analogs. This low cost reliable method was applied for AFB1 monitoring in the poultry chain of a high agribusiness potential region (northern Paraná state, Brazil). Maize, laying hens feed and egg samples were collected from two poultry farms (with production above 200,000 eggs/day) and evaluated by intralaboratory validated ic-ELISA. The sensitivity of such a validated assay, detecting picogram levels of aflatoxins, demonstrated to be proper for surveying daily ingested cumulative toxins and estimating risks. Additionally, more than 61.00% of positive egg samples ranged between the limit of quantification (LOQ – 0.035 ng/g) and 1.00 ng/g, values commonly not covered by commercial kits. Positive data (>LOQ) occurred in 22 maize (56.40%), 34 feed (85.00%) and 192 (48.00%) egg samples. Mean contamination in maize was 1.51±0.94 ng/g (range 0.11-3.91 ng/g), 1.26±0.96 ng/g in feed (0.10-3.58 ng/g), and 1.01±0.77 ng/g in egg (0.05-3.85 ng/g). No statistical difference was observed between farms (P>0.05) for any of the matrices analysed. However, the difference between median values in maize (0.98 ng/g – Farm A; 1.76 ng/g – Farm B) indicated a higher contamination trend in farm B, possibly due to inadequate local storage. Although there is no limit stipulated for AFB1 contamination in eggs, the levels detected in samples were low and do not represent an immediate risk to animal production or human consumption. Nevertheless, the high frequency of positive maize and feed samples in this field of agribusiness should be highlighted. Sensitive aflatoxin monitoring procedures must be strategically carried out from raw materials to animal derived products, aiming harmless production, which also assures human health.

Surface temperature determination using long range thermal emission spectroscopy based on a first order scanning Fabry-Pérot interferometer

Determination of the surface temperature of different materials based on thermographic imaging is a difficult task as the thermal emission spectrum is both temperature and emissivity dependent. Without prior knowledge of the emissivity of the object under investigation, it makes up a temperature-emissivity underdetermined system. This work demonstrates the possibility of recognizing specific materials from hyperspectral thermal images (HSTI) in the wavelength range from 8-14 µm. The hyperspectral images were acquired using a microbolometer sensor array in combination with a scanning 1^st order Fabry-Pérot interferometer acting as a bandpass filter. A logistic regression model was used to successfully differentiate between polyimide tape, sapphire, borosilicate glass, fused silica, and alumina ceramic at temperatures as low as 34.0 ± 0.05 °C. Each material was recognized with true positive rates above 94% calculated from individual pixel spectra. The surface temperature of the samples was subsequently predicted using pre-fitted partial least squares (PLS) models, which predicted all surface temperature values with a common root mean square error (RMSE) of 1.10 °C and thereby outperforming conventional thermography. This approach paves the way for a practical solution to the underdetermined temperature-emissivity system.

Approaches to Inactivating Aflatoxins-A Review and Challenges

According to the World Health Organization, the contamination of crops with aflatoxins poses a significant economic burden, estimated to affect 25% of global food crops. In the event that the contaminated food is processed, aflatoxins enter the general food supply and can cause serious diseases. Aflatoxins are distributed unevenly in food or feedstock, making eradicating them both a scientific and a technological challenge. Cooking, freezing, or pressurizing have little effect on aflatoxins. While chemical methods degrade toxins on the surface of contaminated food, the destruction inside entails a slow process. Physical techniques, such as irradiation with ultraviolet photons, pulses of extensive white radiation, and gaseous plasma, are promising; yet, the exact mechanisms concerning how these techniques degrade aflatoxins require further study. Correlations between the efficiency of such degradation and the processing parameters used by various authors are presented in this review. The lack of appropriate guidance while interpreting the observed results is a huge scientific challenge.

Quantitative Proteomic Analysis for High- and Low-Aflatoxin-Yield Aspergillus flavus Strains Isolated From Natural Environments

The molecular mechanisms underlying aflatoxin production have been well-studied in strains of the fungus Aspergillus flavus (A. flavus) under artificial conditions. However, aflatoxin biosynthesis has rarely been studied in A. flavus strains isolated from field conditions with different aflatoxin-producing ability. In the present study, tandem mass tag (TMT) labeling and high-performance liquid chromatography (HPLC) coupled with tandem-mass spectrometry analysis were used for proteomic quantification in natural isolates of high- and low-aflatoxin-yield A. flavus strains. Additionally, findings obtained using the TMT-labeling method were validated using the high-resolution multiple reaction monitoring (MRM-HR) method. In total, 4,363 proteins were quantified, among which 1,045 proteins were differentially expressed between the high- and low-aflatoxin-yield A. flavus strains. Bioinformatics analysis showed that the up-regulated proteins were significantly enriched in carbon-related metabolism and the biosynthesis of secondary metabolites, whereas the down-regulated proteins were enriched in oxidative phosphorylation. Moreover, GST proteins were found to be significantly down-regulated in high-yield A. flavus strains; this result contradicted previous findings obtained from A. flavus strains grown under artificial conditions. In summary, our study provides novel insights into aflatoxin regulation in A. flavus under field conditions and could facilitate the development of various strategies for the effective control of aflatoxin contamination in food crops.

Mycotoxins in Pistachios (Pistacia vera L.): Methods for Determination, Occurrence, Decontamination

The consumption of pistachios (Pistacia vera L.) has been increasing, given their important benefit to human health. In addition to being an excellent nutritional source, they have been associated with chemical hazards, such as mycotoxins, resulting in fungal contamination and its secondary metabolism. Aflatoxins (AFs) are the most common mycotoxins in pistachio and the most toxic to humans, with hepatotoxic effects. More mycotoxins such as ochratoxin A (OTA), fumonisins (FBs), zearalenone (ZEA) and trichothecenes (T2, HT2 and DON) and emerging mycotoxins have been involved in nuts. Because of the low levels of concentration and the complexity of the matrix, the determination techniques must be very sensitive. The present paper carries out an extensive review of the state of the art of the determination of mycotoxins in pistachios, concerning the trends in analytical methodologies for their determination and the levels detected as a result of its contamination. Screening methods based on immunoassays are useful due to their simplicity and rapid response. Liquid chromatography (LC) is the gold standard with new improvements to enhance accuracy, precision and sensitivity and a lower detection limit. The reduction of Aspergillus' and aflatoxins' contamination is important to minimize the public health risks. While prevention, mostly in pre-harvest, is the most effective and preferable measure to avoid mycotoxin contamination, there is an increased number of decontamination processes which will also be addressed in this review.

Development and Validation of QuEChERS Followed by UHPLC-ToF-MS Method for Determination of Multi-Mycotoxins in Pistachio Nuts

Pistachios are one of the types of tree nut fruits with the highest mycotoxin contamination, especially of aflatoxins, worldwide. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method that was followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC-ToF-MS) for the determination of mycotoxins in pistachios. Different approaches to dispersive solid phase extraction as a clean-up method for high lipid matrices were evaluated. For this, classic sorbents such as C18 (octadecyl-modified silica) and PSA (primary secondary amine), and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide), were used. The QuEChERS method, followed by Z-Sep d-SPE clean-up, provided the best analytical performance for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2) in pistachios. The method was validated in terms of linearity, sensitivity, repeatability, interday precision and recovery; it achieved good results according to criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to real samples and the results show that pistachios that are available in Portuguese markets are safe from mycotoxins that are of concern to human health.

Fungal Contamination and Aflatoxin B1 Detected in Hay for Dairy Cows in South Italy

The growth of filamentous fungi on fodder is recognized as responsible for fungal deterioration and mycotoxin contamination of the plant mass leads to economic losses in the dairy cow production system. Mycotoxin contamination has significant implications for human and animal health and is one of the major concerns in the food and feed chain. This research provides an insight into the variety of viable molds (i.e., filamentous microfungi) that can be isolated from hay produced in South Italy and destined to dairy cows. On different lots of hay (n = 55) collected from 20 dairy farms, a total of 33 different fungal species were identified. The most representative was Cladosporium cladosporioides (n = 46, 84%) followed by Alternaria alternata (n = 25, 45%), and Rhizopus stolonifer (n = 24, 44%). The species most closely related to aflatoxin (AF) contamination, Aspergillus flavus, was often isolated (n = 11, 20%). Regarding AF detection, all the hay samples were found to be scarcely contaminated by AFB1 and showed values from 0.0020 to 0.0077 mg/kg, below the limits established by European Union (EU legislation) (0.02 mg/kg). None of the samples were positive for Aspergillia and tested for AFB1 showed results exceeding established limits. Additionally, hay with moisture between 15.0 and 19.2% or crude ash on dry matter content ranging from 14.0 to 15.5% reported an increased presence of AFB1 (p < 0.05) compared to the other samples. All the analyzed hay samples, besides the presence of molds, can be considered safe for the presence of AFB1. Prevention of mold spoilage is mandatory to reduce the exposure of humans and animals to mycotoxins.

Early Detection of Mold-Contaminated Peanuts Using Machine Learning and Deep Features Based on Optical Coherence Tomography

Fungal infection is a pre-harvest and post-harvest crisis for farmers of peanuts. In environments with temperatures around 28 °C to 30 °C or relative humidity of approximately 90%, mold-contaminated peanuts have a considerable likelihood to be infected with Aflatoxins. Aflatoxins are known to be highly carcinogenic, posing danger to humans and livestock. In this work, we proposed a new approach for detection of mold-contaminated peanuts at an early stage. The approach employs the optical coherence tomography (OCT) imaging technique and an error-correcting output code (ECOC) based Support Vector Machine (SVM) trained on features extracted using a pre-trained Deep Convolutional Neural Network (DCNN). To this end, mold-contaminated and uncontaminated peanuts were scanned to create a data set of OCT images used for training and evaluation of the ECOC-SVM model. Results showed that the proposed approach is capable of detecting mold-contaminated peanuts with respective accuracies of approximately 85% and 96% after incubation periods of 48 and 96 h.

Antibody conjugated magnetic nanoparticle based colorimetric assay for the detection and quantification of aflatoxin B1 in wheat grains

Aflatoxin B1 (AFB1) is a most potent carcinogenic secondary metabolite produced by Aspergillus flavus. As a food safety concern, development of a rapid, cost effective, sensitive and easy to use method for the detection of aflatoxin is of prime requirement. In this study, AFB1 was conjugated with bovine serum albumin (BSA), and AFB1-BSA conjugate was purified by HPLC. Purification was confirmed by UV-Vis spectroscopy, FTIR and MALDI-TOF mass spectrometry. The polyclonal antibody was raised against AFB1-BSA conjugate in rabbit and purified by protein A sepharose and BSA sepharose affinity columns. Iron oxide nanoparticles (MNPs) were synthesised by co-precipitation method and their surface was functionalised with (3-aminopropyl) triethoxysilane (APTES). Size of APTES conjugated MNPs was determined by electron microscopy, and characterised by several biophysical techniques. The purified anti-AFB1 antibody was conjugated with surface functionalised MNPs and the conjugation was confirmed by determining the sizes of free and antibody conjugated MNPs by field emission scanning electron microscope where increase of particle sizes from 10-20 to 40-50 nm was observed due to antibody conjugation. Anti-AFB1 antibody conjugated MNPs were used for capturing AFB1 from the aflatoxin spiked wheat grains with a recovery percentage of more than 80% and used effectively five times. The captured AFB1 was then quantified by a sensitive colorimetric assay where colourless AFB1 was first converted into coumaric acid by NaOH. Subsequently, coumaric acid reacted with 2,6-dibromoquinone-4-chloroimide (DBQC) to a green-coloured indophenol product which was quantified spectrophotometrically. AFB1 contamination as low as 2 μg/kg in wheat grains was detected by the developed technique suggesting its potential application for both qualitative and quantitative analysis of aflatoxins present in feed and food materials.

Detection of aflatoxin M1 in bovine milk from different agro-climatic zones of Chhattisgarh, India, using HPLC-FLD and assessment of human health risks

Concerns regarding food safety and 'One Health' are increasing globally. Aflatoxin M₁ (AFM₁), a human carcinogenic toxin, is excreted by lactating animals in their milk after consumption of feed contaminated with aflatoxin B₁. The present cross-sectional study aimed to determine the occurrence of AFM₁ in cattle and buffalo milk produced in rural and peri-urban areas under different agro-climatic conditions of Chhattisgarh, India, and assesses human health risks. Analyses of 545 milk samples by validated high-performance liquid chromatography revealed high level of AFM₁ contamination in 224 (41.1%) samples with mean concentration of 0.137 ± 0.029 μg/L. Statistically significant differences (p< 0.05) were observed in the levels and frequency of AFM₁ occurrence among different agro-climatic zones. AFM₁ was more frequently detected in milk samples from Northern hills (64%) followed by Bastar plateau (40.7%) and Chhattisgarh plain (27.3%), with mean concentration levels of 0.396 ± 0.099 μg/L, 0.081 ± 0.025 μg/L and 0.013 ± 0.002 μg/L, respectively. Species wise no significant difference was observed in the detection frequency and concentration of AFM₁ in milk from cattle and buffalo. AFM₁ contamination above maximum permissible limits established by European commission and Food Safety and Standard Authority of India was detected in 21.3% and 4.4% of samples, respectively. The estimated daily intakes for AFM₁ were found to be higher than tolerable daily intakes for both adults and children, especially of Northern hills implying a potentially high risk to consumer's health. This study provides valuable information on the contamination status of milk in one of the fastest developing state of India. It also highlights the importance and need for continuous farmers' awareness on good animal husbandry practices, routine surveillance of mycotoxins in animal feeds and food commodities to safeguard human health.

The Existing Methods and Novel Approaches in Mycotoxins' Detection

Mycotoxins represent a wide range of secondary, naturally occurring and practically unavoidable fungal metabolites. They contaminate various agricultural commodities like cereals, maize, peanuts, fruits, and feed at any stage in pre- or post-harvest conditions. Consumption of mycotoxin-contaminated food and feed can cause acute or chronic toxicity in human and animals. The risk that is posed to public health have prompted the need to develop methods of analysis and detection of mycotoxins in food products. Mycotoxins wide range of structural diversity, high chemical stability, and low concentrations in tested samples require robust, effective, and comprehensible detection methods. This review summarizes current methods, such as chromatographic and immunochemical techniques, as well as novel, alternative approaches like biosensors, electronic noses, or molecularly imprinted polymers that have been successfully applied in detection and identification of various mycotoxins in food commodities. In order to highlight the significance of sampling and sample treatment in the analytical process, these steps have been comprehensively described.

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.

Aflatoxin B1 and ochratoxin A in imported and Lebanese wheat and -products

AFB₁ and OTA are produced in food products due to climatic conditions like temperature and humidity. In Lebanon, few studies address AFB₁ and OTA contamination in wheat and wheat products. In this study, a total of 312 samples of wheat and wheat products were collected from different sites, including port, silos, mills, and supermarkets were analysed. Wheat and wheat products consumption in Lebanon was quantified using a food frequency questionnaire. Exposure to AFB₁ and OTA was calculated and liver and kidney cancer risk were evaluated. Results showed that AFB₁ and OTA were, respectively, found in 65.7% and 100% of the samples, with 0.6% and 17.6% exceeding the maximum limit set by the European Commission. AFB₁ was shown to be associated with 0.076 additional cancer cases per 100,000 persons per year and OTA weekly exposure was shown to be 53.2 ng/kg bw, which is less than the Provisional Tolerable Weekly Intake of 100 ng/kg bw.

An overview of nanomaterial based biosensors for detection of Aflatoxin B1 toxicity in foods

Aflatoxin B1 (AFB1) is one of the most potent mycotoxin contaminating several foods and feeds. It suppresses immunity and consequently increases mutagenicity, carcinogenicity, teratogenicity, hepatotoxicity, embryonic toxicity and increasing morbidity and mortality. Continuous exposure of AFB1 causes liver damage and thus increases the prevalence of cirrhosis and hepatic cancer. This article was planned to provide understanding of AFB1 toxicity and provides future directions for fabrication of cost effective and user-friendly nanomaterials based analytical devices. In the present article various conventional (chromatographic & spectroscopic), modern (PCR & immunoassays) and nanomaterials based biosensing techniques (electrochemical, optical, piezoelectrical and microfluidic) are discussed alongwith their merits and demerits. Nanomaterials based amperometric biosensors are found to be more stable, selective and cost-effective analytical devices in comparison to other biosensors. But many unresolved issues about their stability, toxicity and metabolic fate needs further studies. In-depth studies are needed for development of advanced nanomaterials integrated biosensors for specific, sensitive and fast monitoring of AFB1 toxicity in foods. Integration of biosensing system with micro array technology for simultaneous and automated detection of multiple AFs in real samples is also needed. Concerted efforts are also required to reduce their possible hazardous consequences of nanomaterials based biosensors.

The Scourge of Aflatoxins in Kenya: A 60-Year Review (1960 to 2020)

Aflatoxins are endemic in Kenya. The 2004 outbreak of acute aflatoxicosis in the country was one of the unprecedented epidemics of human aflatoxin poisoning recorded in mycotoxin history. In this study, an elaborate review was performed to synthesize Kenya’s major findings in relation to aflatoxins, their prevalence, detection, quantification, exposure assessment, prevention, and management in various matrices. Data retrieved indicate that the toxins are primarily biosynthesized by Aspergillus flavus and A. parasiticus, with the eastern part of the country reportedly more aflatoxin-prone. Aflatoxins have been reported in maize and maize products (Busaa, chan’gaa, githeri, irio, muthokoi, uji, and ugali), peanuts and its products, rice, cassava, sorghum, millet, yams, beers, dried fish, animal feeds, dairy and herbal products, and sometimes in tandem with other mycotoxins. The highest total aflatoxin concentration of 58,000 μg/kg has been reported in maize. At least 500 acute human illnesses and 200 deaths due to aflatoxins have been reported. The causes and prevalence of aflatoxins have been grossly ascribed to poor agronomic practices, low education levels, and inadequate statutory regulation and sensitization. Low diet diversity has aggravated exposure to aflatoxins in Kenya because maize as a dietetic staple is aflatoxin-prone. Detection and surveillance are only barely adequate, though some exposure assessments have been conducted. There is a need to widen diet diversity as a measure of reducing exposure due to consumption of aflatoxin-contaminated foods.

Aflatoxin contamination and recommendations to improve its control: a review

Aflatoxin producing fungi cause contamination of food and feed resulting in health hazards and economic loss. It is imperative to develop workable control measures throughout the food chain to prevent and reduce aflatoxin contamination. This is a critical review of contemporary published papers in the field. It is a review of reports from the original aflatoxin researches conducted on foods, from 2015-2020. Most of the reports show high aflatoxin contaminations in food at levels that exceed a regulatory limit of 20 μg/kg and 4 μg/kg set for foods for human consumption in the USA and European Union, respectively. The highest aflatoxin concentration (3,760 μg/kg) was observed in maize. Some of the strategies being deployed in aflatoxin control include application of biocontrol agents, specifically of Aflasafe™, development of resistant crop varieties, and application of other good agricultural practices. We recommend the adoption of emerging technologies such as combined methods technology (CMT) or hurdle technology, one health concept (OHC), improved regulations, on-line monitoring of aflatoxins, and creative art intervention (CAI) to prevent or restrict the growth of target aflatoxin causative fungi.

Advances in nanomaterial-based electrochemical biosensors for the detection of microbial toxins, pathogenic bacteria in food matrices

There is a growing demand to protect food products against the hazard of microbes and their toxins. To satisfy such goals, it is important to develop highly sensitive, reliable, sophisticated, rapid, and cost-effective sensing techniques such as electrochemical sensors/biosensors. Although diverse forms of nanomaterials (NMs)-based electrochemical sensing methods have been introduced in markets, the reliability of commercial products is yet insufficient to meet the practical goal. In this review, we focused on: 1) sources of pathogenic microbes and their toxins; 2) possible routes of their entrainment in food, and 3) current development of NM-based biosensors to realize real-time detection of the target analytes. At last, future prospects and challenges in this research field are discussed.