The Existing Methods and Novel Approaches in Mycotoxins' Detection

Infant exposure to ochratoxin A, zearalenone, and deoxynivalenol from the consumption of milk formula and baby cereal in Chile

Ochratoxin A (OTA), zearalenone (ZEN), and deoxynivalenol (DON) are mycotoxins whose exposure is associated with various adverse health effects, including cancer and renal disorders, estrogenic effects, and immunosuppressive and gastrointestinal disorders, respectively. Infants (<2 years) are the most vulnerable group to mycotoxins, representing a unique combination of restricted food consumption types, low body weight, lower ability to eliminate toxins, and more future years to accumulate toxins. This study aimed to estimate the infant́s exposure to OTA, DON, and ZEN due to the consumption of milk formula and baby cereals in Chile. Milk formula samples (n = 41) and baby cereals (n = 30) were collected and analyzed using commercial ELISA kits for OTA, DON, and ZEA determination. Exposure was assessed by the Estimated Daily Intake (EDI) approach (mean and worst-case scenario, WCS) with the levels found in a modified Lower Bound (mLB) and Upper Bound (UB); ideal consumption (<6m, 7-12 m, and 13-24 m); adjusted by the weight of each group. The risk was estimated by comparing the EDI with a reference tolerable daily intake or by the margin of exposure (MOE) in the case of OTA. DON and OTA occurrence in infant formula were 34 % and 41 %, respectively. The co-occurrence between these mycotoxins was 22 %. Mycotoxin contents were below LOQ values except for OTA determined in one sample (0.29 ng/ml). No milk formulae were contaminated with ZEN. In the case of baby cereals, the occurrences were 17 % for OTA, 30 % for DON, and 7 % for ZEN, all below LOQ. Co-occurrence was seen in two samples between ZEN and OTA. According to exposure calculations, the MOE for OTA was less than 10,000 in all models for milk formula between 0 to 12 months of age and in the UB and WCS for cereal consumption. Health concerns were observed for DON in the WCS and UB for milk consumption in all ages and only in the UB WCS for cereal consumption. Considering the high consumption of milk formula in these age groups, regulation of OTA and other co-occurring mycotoxins in infant milk and food is strongly suggested.

Near-infrared spectroscopy based on colorimetric sensor array coupled with convolutional neural network detecting zearalenone in wheat

Wheat is a vital global cereal crop, but its susceptibility to contamination by mycotoxins can render it unusable. This study explored the integration of two novel non-destructive detection methodologies with convolutional neural network (CNN) for the identification of zearalenone (ZEN) contamination in wheat. Firstly, the colorimetric sensor array composed of six selected porphyrin-based materials was used to capture the olfactory signatures of wheat samples. Subsequently, the colorimetric sensor array, after undergoing a reaction, was characterized by its near-infrared spectral features. Then, the CNN quantitative analysis model was proposed based on the data, alongside the establishment of traditional machine learning models, partial least squares regression (PLSR) and support vector machine regression (SVR), for comparative purposes. The outcomes demonstrated that the CNN model had superior predictive performance, with a root mean square error of prediction (RMSEP) of 40.92 μ g ∙ kg-1 and a coefficient of determination on the prediction (R P 2 ) of 0.91. These results affirmed the potential of integrating colorimetric sensor array with near-infrared spectroscopy in evaluating the safety of wheat and potentially other grains. Moreover, CNN can have the capacity to autonomously learn and distill features from spectral data, enabling further spectral analysis and making it a forward-looking spectroscopic tool.

Recent advances in nanomaterial-based optical biosensors for food safety applications: Ochratoxin-A detection, as case study

Global population growth tremendously impacts the global food industry, endangering food safety and quality. Mycotoxins, particularly Ochratoxin-A (OTA), emerge as a food chain production threat, since it is produced by fungus that contaminates different food species and products. Beyond this, OTA exhibits a possible human toxicological risk that can lead to carcinogenic and neurological diseases. A selective, sensitive, and reliable OTA biodetection approach is essential to ensure food safety. Current detection approaches rely on accurate and time-consuming laboratory techniques performed at the end of the food production process, or lateral-flow technologies that are rapid and on-site, but do not provide quantitative and precise OTA concentration measurements. Nanoengineered optical biosensors arise as an avant-garde solution, providing high sensing performance, and a fast and accurate OTA biodetection screening, which is attractive for the industrial market. This review core presents and discusses the recent advancements in optical OTA biosensing, considering engineered nanomaterials, optical transduction principle and biorecognition methodologies. Finally, the major challenges and future trends are discussed, and current patented OTA optical biosensors are emphasized for a particular promising detection method.

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.

Addressing the Concern of Orange-Yellow Fungus Growth on Palm Kernel Cake: Safeguarding Dairy Cattle Diets for Mycotoxin-Producing Fungi

Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador's animal feed industry. The emergence of yellow-orange fungal growth in PKC on some cattle farms in Ecuador sparked concerns within the cattle industry regarding a potential mycotoxin-producing fungus on this substrate. Due to the limited availability of analytical chemistry techniques in Ecuador for mycotoxin detection, we chose to isolate and identify the fungus to determine its association with mycotoxin-producing genera. Through molecular identification via ITS region sequencing, we identified the yellow-orange fungus as the yeast Candida ethanolica. Furthermore, we isolated two other fungi-the yeast Pichia kudriavzevii, and the fungus Geotrichum candidum. Molecular identification confirmed that all three species are not classified as mycotoxin-producing fungi but in contrast, the literature indicates that all three have demonstrated antifungal activity against Aspergillus and Penicillium species, genera associated with mycotoxin production. This suggests their potential use in biocontrol to counter the colonization of harmful fungi. We discuss preventive measures against the fungal invasion of PKC and emphasize the importance of promptly identifying fungi on this substrate. Rapid recognition of mycotoxin-producing and pathogenic genera holds the promise of mitigating cattle intoxication and the dissemination of mycotoxins throughout the food chain.

Aflatoxins: Occurrence, biosynthesis, mechanism of action and effects, conventional/emerging detection techniques

Aflatoxins (AFs) are toxic secondary metabolites prevalent in various food and agricultural products, posing significant challenges to global food safety. The detection and quantification of AFs through high-precision analytical techniques are crucial in mitigating AF contamination levels and associated health risks. Variousmethods,including conventional and emerging techniques, have been developed for detecting and quantifyingAFsinfood samples. This review provides an in-depth analysis of the global occurrence of AF in food commodities, covering their biosynthesis, mode of action, and effects on humans and animals. Additionally, the review discusses different conventional strategies, including chromatographic and immunochemical approaches, for AF quantification and identification in food samples. Furthermore, emerging AF detection strategies, such as solid-state gas sensors and electronic nose technologies, along with their applications, limitations, and future perspectives, were reviewed. Sample purification, along with their respective advantages and limitations, are also discussed herein.

Mycotoxins evaluation of total mixed ration (TMR) in bovine dairy farms: An update

The total mixed ration (TMR) is currently a widespread method to feed dairy cows. It is a mixture of raw fodder and concentrate feed that can be contaminated by several mycotoxins. The main aim of this paper was to provide a critical review on TMR mycotoxin occurrence and its usefulness to monitor and control them on-farm. Aflatoxins, zearalenone, deoxynivalenol, T-2 toxin and fumonisins (regulated mycotoxins) are the most prevalent mycotoxins evaluated in TMR. Nonetheless, several emerging mycotoxins represent a health risk at the animal level regarding their prevalence and level in TMR. Even when measured at low levels, the co-occurrence of mycotoxins is frequent and synergistic effects on animal health are still underevaluated. Similar to the animal feed industry, on-farm plans monitoring mycotoxin feed contamination can be developed as a herd health management program. The estimated daily intake of mycotoxins should be implemented, but thresholds for each mycotoxin are not currently defined in dairy farms.

Low-Cost Pocket Fluorometer and Chemometric Tools for Green and Rapid Screening of Deoxynivalenol in Durum Wheat Bran

Cereal crops are frequently contaminated by deoxynivalenol (DON), a harmful type of mycotoxin produced by several Fusarium species fungi. The early detection of mycotoxin contamination is crucial for ensuring safety and quality of food and feed products, for preventing health risks and for avoiding economic losses because of product rejection or costly mycotoxin removal. A LED-based pocket-size fluorometer is presented that allows a rapid and low-cost screening of DON-contaminated durum wheat bran samples, without using chemicals or product handling. Forty-two samples with DON contamination in the 40-1650 µg/kg range were considered. A chemometric processing of spectroscopic data allowed distinguishing of samples based on their DON content using a cut-off level set at 400 µg/kg DON. Although much lower than the EU limit of 750 µg/kg for wheat bran, this cut-off limit was considered useful whether accepting the sample as safe or implying further inspection by means of more accurate but also more expensive standard analytical techniques. Chemometric data processing using Principal Component Analysis and Quadratic Discriminant Analysis demonstrated a classification rate of 79% in cross-validation. To the best of our knowledge, this is the first time that a pocket-size fluorometer was used for DON screening of wheat bran.

Evaluation of ELISA and immunoaffinity fluorometric analytical tools of four mycotoxins in various food categories

Mycotoxins (MTs) are secondary toxic metabolites that can contaminate food, impacting quality and safety, leading to various negative health effects and serious pathological consequences conferring urgent need to evaluate and validate the currently standard methods used in their analysis. Therefore, this study was aimed to validate ELISA and VICAM immunoaffinity fluorometric, the two common methods used to monitor the level of MTs according to the Egyptian Organization for Standardization and Quality Control. A total of 246 food samples were collected and tested for Aflatoxins (196 samples), Ochratoxin A (139), Zearalenone (70), and Deoxynivalenol (100) using both analytical methods. Results showed that aflatoxins exceeded limits in 42.9, 100, and 13.3% of oily seeds, dried fruits, and chili and spices, respectively. For ochratoxin A, 3.9% of Gramineae and 8% of spices and chili (locally sourced) exceeded the limits, while 17.6% of imported pasta and noodles exceeded the limits for deoxynivalenol. Significant differences for the aflatoxins and ochratoxin A detection among different categories of chocolate, dried fruits, and oily seeds (p-value < 0.05). No zearalenone contamination was detected in the exported, imported, and locally sourced categories. No deoxynivalenol contamination was detected in the tested Gramineae category. In contrast, for pasta and noodles, the imported samples exhibited the highest contamination rate (above the upper limit of 750 µg/kg) with 17.6% of the samples testing positive for deoxynivalenol with no significant difference among different sample categories of Gramineae, pasta, and noodles (p-value > 0.05). In conclusion, our study found no significant differences between the ELISA and immunoaffinity fluorometric analysis in the detection of the respective MTs in various food categories and therefore, they can substitute each other whenever necessary. However, significant differences were observed among different food categories, particularly the local and imported ones, highlighting the urgent need for strict and appropriate control measures to minimize the risk of MTs adverse effects.

A comparative review on methods of detection and quantification of mycotoxins in solid food and feed: a focus on cereals and nuts

Many emerging factors and circumstances urge the need to develop and optimize the detection and quantification techniques of mycotoxins in solid food and feed. The diversity of mycotoxins, which have different properties and affinities, makes the standardization of the analytical procedures and the adoption of a single protocol that covers the attributes of all mycotoxins a tedious or even an impossible mission. Several modifications and improvements have been undergone in order to optimize the performance of these methods including the extraction solvents, the extraction methods, the clean-up procedures, and the analytical techniques. The techniques range from the rapid screening methods, which lack sensitivity and specificity such as TLC, to a spectrum of more advanced protocols, namely, ELISA, HPLC, and GC-MS and LC-MS/MS. This review aims at assessing the current studies related to these analytical techniques of mycotoxins in solid food and feed. It discusses and evaluates, through a critical approach, various sample treatment techniques, and provides an in-depth examination of different mycotoxin detection methods. Furthermore, it includes a comparison of their actual accuracy and a thorough analysis of the observed benefits and drawbacks.

Mycotoxin Occurrence in Milk and Durum Wheat Samples from Tunisia Using Dispersive Liquid-Liquid Microextraction and Liquid Chromatography with Fluorescence Detection

Food and feed contamination with mycotoxins is a major public health concern. Humans and animals are exposed to these toxins by consuming contaminated products throughout their lives. In this study, a method based on dispersive liquid-liquid microextraction (DLLME), followed by liquid chromatography with fluorescence detection (LC-FLD), was validated for the determination of aflatoxins (AFs) M1, B1, B2, G1, G2, zearalenone (ZEN), and ochratoxin A (OTA). The method was applied to 150 raw cow milk samples and 90 market durum wheat samples from two Tunisian climatic regions: the littoral region (Mahdia) and the continental region (Béja). This work was carried out to obtain more surveillance data to support rapid initiatives to assure safe foods and protect consumer health and to estimate the daily exposure of the Tunisian population consuming those products. AFG2 and OTA were found in wheat with incidences of 54.4 and 11.1%, respectively. On the other side, milk samples were contaminated by AFG2, AFB1, and AFB2 with incidences of 8.7%, 2.0%, and 0.67%, respectively. Some of the samples showed OTA concentrations above the maximum limit allowed by the European Union, which represents a health risk for consumers in Tunisia, where no legislation exists about the maximum content of mycotoxins in food.

Effect of the Consolidation Level on Organic Volatile Compound Emissions from Maize during Storage

The aim of this study was to determine the emission of organic volatile compounds from maize grain as a function of granularity and packing density of bulk material in conditions imitating processes occurring in silos. The study was carried out with the use of a gas chromatograph and an electronic nose, which was designed and constructed at the Institute of Agrophysics of PAS and has a matrix of eight MOS (metal oxide semiconductor) sensors. A 20-L volume of maize grain was consolidated in the INSTRON testing machine with pressures of 40 and 80 kPa. The control samples were not compacted, and the maize bed had bulk density. The analyses were carried out at a moisture content of 14% and 17% (w.b.-wet basis). The measurement system facilitated quantitative and qualitative analyses of volatile organic compounds and the intensity of their emission during 30-day storage. The study determined the profile of volatile compounds as a function of storage time and the grain bed consolidation level. The research results indicated the degree of grain degradation induced by the storage time. The highest emission of volatile compounds was recorded on the first four days, which indicated a dynamic nature of maize quality degradation. This was confirmed by the measurements performed with electrochemical sensors. In turn, the intensity of the volatile compound emission decreased in the next stage of the experiments, which showed a decline in the quality degradation dynamics. The sensor responses to the emission intensity decreased significantly at this stage. The electronic nose data on the emission of VOCs (volatile organic compounds) as well as grain moisture and bulk volume can be helpful for the determination of the quality of stored material and its suitability for consumption.

Recent Advances in Mycotoxin Determination in Fish Feed Ingredients

Low-cost plant-based sources used in aquaculture diets are prone to the occurrence of animal feed contaminants, which may in certain conditions affect the quality and safety of aquafeeds. Mycotoxins, a toxic group of small organic molecules produced by fungi, comprise a frequently occurring plant-based feed contaminant in aquafeeds. Mycotoxin contamination can potentially cause significant mortality, reduced productivity, and higher disease susceptibility; thus, its timely detection is crucial to the aquaculture industry. The present review summarizes the methodological advances, developed mainly during the past decade, related to mycotoxin detection in aquafeed ingredients, namely analytical, chromatographic, and immunological methodologies, as well as the use of biosensors and spectroscopic methods which are becoming more prevalent. Rapid and accurate mycotoxin detection is and will continue to be crucial to the food industry, animal production, and the environment, resulting in further improvements and developments in mycotoxin detection techniques.

Fungal identification in peanuts seeds through multispectral images: Technological advances to enhance sanitary quality

The sanitary quality of seed is essential in agriculture. This is because pathogenic fungi compromise seed physiological quality and prevent the formation of plants in the field, which causes losses to farmers. Multispectral images technologies coupled with machine learning algorithms can optimize the identification of healthy peanut seeds, greatly improving the sanitary quality. The objective was to verify whether multispectral images technologies and artificial intelligence tools are effective for discriminating pathogenic fungi in tropical peanut seeds. For this purpose, dry peanut seeds infected by fungi (A. flavus, A. niger, Penicillium sp., and Rhizopus sp.) were used to acquire images at different wavelengths (365 to 970 nm). Multispectral markers of peanut seed health quality were found. The incubation period of 216 h was the one that most contributed to discriminating healthy seeds from those containing fungi through multispectral images. Texture (Percent Run), color (CIELab L*) and reflectance (490 nm) were highly effective in discriminating the sanitary quality of peanut seeds. Machine learning algorithms (LDA, MLP, RF, and SVM) demonstrated high accuracy in autonomous detection of seed health status (90 to 100%). Thus, multispectral images coupled with machine learning algorithms are effective for screening peanut seeds with superior sanitary quality.

Composition-Based Risk Estimation of Mycotoxins in Dry Dog Foods

The risk of mycotoxins co-occurrence in extrusion-produced dry foods increases due to their composition based on various grains and vegetables. This study aimed to validate a risk estimation for the association between ingredients and the ELISA-detected levels of DON, FUM, ZEA, AFs, T2, and OTA in 34 dry dog food products. The main ingredients were corn, beet, and oil of different origins (of equal frequency, 79.41%), rice (67.6%), and wheat (50%). DON and FUM had the strongest positive correlation (0.635, p = 0.001). The presence of corn in the sample composition increased the median DON and ZEA levels, respectively, by 99.45 μg/kg and 65.64 μg/kg, p = 0.011. In addition to DON and ZEA levels, integral corn presence increased the FUM median levels by 886.61 μg/kg, p = 0.005. For corn gluten flour-containing samples, DON, FUM, and ZEA median differences still existed, and OTA levels also differed by 1.99 μg/kg, p < 0.001. Corn gluten flour presence was strongly associated with DON levels > 403.06 μg/kg (OR = 38.4, RR = 9.90, p = 0.002), FUM levels > 1097.56 μg/kg (OR = 5.56, RR = 1.45, p = 0.048), ZEA levels > 136.88 μg/kg (OR = 23.00, RR = 3.09, p = 0.002), and OTA levels > 3.93 μg/kg (OR = 24.00, RR = 3.09, p = 0.002). Our results suggest that some ingredients or combinations should be avoided due to their risk of increasing mycotoxin levels.

Mycotoxins Contamination in Rice: Analytical Methods, Occurrence and Detoxification Strategies

The prevalence of mycotoxins in the environment is associated with potential crop contamination, which results in an unavoidable increase in human exposure. Rice, being the second most consumed cereal worldwide, constitutes an important source of potential contamination by mycotoxins. Due to the increasing number of notifications reported, and the occurrence of mycotoxins at levels above the legislated limits, this work intends to compile the most relevant studies and review the main methods used in the detection and quantification of these compounds in rice. The aflatoxins and ochratoxin A are the predominant mycotoxins detected in rice grain and these data reveal the importance of adopting safety storage practices that prevent the growth of producing fungi from the Aspergillus genus along all the rice chain. Immunoaffinity columns (IAC) and QuECHERS are the preferred methods for extraction and purification and HPLC-MS/MS is preferred for quantification purposes. Further investigation is still required to establish the real exposition of these contaminants, as well as the consequences and possible synergistic effects due to the co-occurrence of mycotoxins and also for emergent and masked mycotoxins.

Progress and challenges in sensing of mycotoxins using molecularly imprinted polymers

Mycotoxin is toxic secondary metabolite formed by certain filamentous fungi. This toxic compound can enter the food chain through contamination of food (e.g., by colonization of toxigenic fungi on food). In light of the growing concerns on the health hazards posed by mycotoxins, it is desirable to develop reliable analytical tools for their detection in food products in both sensitive and efficient manner. For this purpose, the potential utility of molecularly imprinted polymers (MIPs) has been explored due to their meritful properties (e.g., large number of tailor-made binding sites, sensitive template molecules, high recognition specificity, and structure predictability). This review addresses the recent advances in the application of MIPs toward the sensing of various mycotoxins (e.g., aflatoxins and patulin) along with their fabrication strategies. Then, performance evaluation is made for various types of MIP- and non-MIP-based sensing platforms built for the listed target mycotoxins in terms of quality assurance such as limit of detection (LOD). Further, the present challenges in the MIP-based sensing application of mycotoxins are discussed along with the future outlook in this research field.

Recent Progress in Rapid Determination of Mycotoxins Based on Emerging Biorecognition Molecules: A Review

Mycotoxins are secondary metabolites produced by fungal species, which pose significant risk to humans and livestock. The mycotoxins which are produced from Aspergillus, Penicillium, and Fusarium are considered most important and therefore regulated in food- and feedstuffs. Analyses are predominantly performed by official laboratory methods in centralized labs by expert technicians. There is an urgent demand for new low-cost, easy-to-use, and portable analytical devices for rapid on-site determination. Most significant advances were realized in the field bioanalytical techniques based on molecular recognition. This review aims to discuss recent progress in the generation of native biomolecules and new bioinspired materials towards mycotoxins for the development of reliable bioreceptor-based analytical methods. After brief presentation of basic knowledge regarding characteristics of most important mycotoxins, the generation, benefits, and limitations of present and emerging biorecognition molecules, such as polyclonal (pAb), monoclonal (mAb), recombinant antibodies (rAb), aptamers, short peptides, and molecularly imprinted polymers (MIPs), are discussed. Hereinafter, the use of binders in different areas of application, including sample preparation, microplate- and tube-based assays, lateral flow devices, and biosensors, is highlighted. Special focus, on a global scale, is placed on commercial availability of single receptor molecules, test-kits, and biosensor platforms using multiplexed bead-based suspension assays and planar biochip arrays. Future outlook is given with special emphasis on new challenges, such as increasing use of rAb based on synthetic and naïve antibody libraries to renounce animal immunization, multiple-analyte test-kits and high-throughput multiplexing, and determination of masked mycotoxins, including stereoisomeric degradation products.