Detection and quantification of zearalenone and its modified forms in enzymatically treated oat and wheat flour

Fusarium mycotoxins: The major food contaminants

Mycotoxins, which are secondary metabolites produced by toxicogenic fungi, are natural food toxins that cause acute and chronic adverse reactions in humans and animals. The genus Fusarium is one of three major genera of mycotoxin-producing fungi. Trichothecenes, fumonisins, and zearalenone are the major Fusarium mycotoxins that occur worldwide. Fusarium mycotoxins have the potential to infiltrate the human food chain via contamination during crop production and food processing, eventually threatening human health. The occurrence and development of Fusarium mycotoxin contamination will change with climate change, especially with variations in temperature, precipitation, and carbon dioxide concentration. To address these challenges, researchers have built a series of effective models to forecast the occurrence of Fusarium mycotoxins and provide guidance for crop production. Fusarium mycotoxins frequently exist in food products at extremely low levels, thus necessitating the development of highly sensitive and reliable detection techniques. Numerous successful detection methods have been developed to meet the requirements of various situations, and an increasing number of methods are moving toward high-throughput features. Although Fusarium mycotoxins cannot be completely eliminated, numerous agronomic, chemical, physical, and biological methods can lower Fusarium mycotoxin contamination to safe levels during the preharvest and postharvest stages. These theoretical innovations and technological advances have the potential to facilitate the development of comprehensive strategies for effectively managing Fusarium mycotoxin contamination in the future.

Development of a corn flour certified reference material for the accurate determination of zearalenone

A certified reference material (CRM, KRISS 108-01-002) for zearalenone in corn flour was developed to assure reliable and accurate measurements in testing laboratories. Commercially available corn flour underwent freeze-drying, pulverization, sieving, and homogenization. The final product was packed in amber bottles, approximately 14 g per unit, and preserved at -70 °C. 13C18-Zearalenone was used as an internal standard (IS) for the certification of zearalenone by isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC‒MS/MS) and for the analysis of α-zearalenol, β-zearalenol, and zearalanone by LC‒MS/MS. The prepared CRM was sufficiently homogeneous, as the among-unit relative standard deviation for each mycotoxin ranged from 2.2 to 5.7 %. Additionally, the stability of the mycotoxins in the CRM was evaluated under different temperature conditions and scheduled test periods, including storage at -70°C, -20°C, and 4°C and room temperature for up to 12 months, 6 months, and 1 month, respectively. The content of each target mycotoxin in the CRM remained stable throughout the monitoring period at each temperature. Zearalenone content (153.6 ± 8.0 µg/kg) was assigned as the certified value. Meanwhile, the contents of α-zearalenol (1.30 ± 0.17 µg/kg), β-zearalenol (4.75 ± 0.33 µg/kg), and zearalanone (2.09 ± 0.16 µg/kg) were provided as informative values.

Recent Advances in the Detection of Food Toxins Using Mass Spectrometry

Edibles are the only source of nutrients and energy for humans. However, ingredients of edibles have undergone many physicochemical changes during preparation and storage. Aging, hydrolysis, oxidation, and rancidity are some of the major changes that not only change the native flavor, texture, and taste of food but also destroy the nutritive value and jeopardize public health. The major reasons for the production of harmful metabolites, chemicals, and toxins are poor processing, inappropriate storage, and microbial spoilage, which are lethal to consumers. In addition, the emergence of new pollutants has intensified the need for advanced and rapid food analysis techniques to detect such toxins. The issue with the detection of toxins in food samples is the nonvolatile nature and absence of detectable chromophores; hence, normal conventional techniques need additional derivatization. Mass spectrometry (MS) offers high sensitivity, selectivity, and capability to handle complex mixtures, making it an ideal analytical technique for the identification and quantification of food toxins. Recent technological advancements, such as high-resolution MS and tandem mass spectrometry (MS/MS), have significantly improved sensitivity, enabling the detection of food toxins at ultralow levels. Moreover, the emergence of ambient ionization techniques has facilitated rapid in situ analysis of samples with lower time and resources. Despite numerous advantages, the widespread adoption of MS in routine food safety monitoring faces certain challenges such as instrument cost, complexity, data analysis, and standardization of methods. Nevertheless, the continuous advancements in MS-technology and its integration with complementary techniques hold promising prospects for revolutionizing food safety monitoring. This review discusses the application of MS in detecting various food toxins including mycotoxins, marine biotoxins, and plant-derived toxins. It also explores the implementation of untargeted approaches, such as metabolomics and proteomics, for the discovery of novel and emerging food toxins, enhancing our understanding of potential hazards in the food supply chain.

Relevance of Zearalenone and its modified forms in bakery products

Zearalenone is a frequently occurring and well-known mycotoxin developed in cereals before and during the harvest period by Fusarium spp. mainly in maize and wheat. In addition to the main form, various modified forms (phase I and II metabolites) were detected, in some cases in high amounts. These modified forms can be harmful for human health due to their different toxicity, which can be much higher compared to the parent toxin. In addition, the parent toxin can be cleaved from the phase I and II metabolites during digestion. A risk of correlated and additive adverse effects of the metabolites of ZEN phase I and II in humans and animals is evident. ZEN is considered in many studies on its occurrence in grain-based foods and some studies are dedicated to the behavior of ZEN during food processing. This is not the case for the ZEN phase I and II metabolites, which are only included in a few occurrence reports. Their effects during food processing is also only sporadically addressed in studies to date. In addition to the massive lack of data on the occurrence and behavior of ZEN modified forms, there is also a lack of comprehensive clarification of the toxicity of the numerous different ZEN metabolites detected to date. Finally, studies on the fate during digestion of the relevant ZEN metabolites will be important in the future to further clarify their relevance in processed foods such as bakery products.

Metabolomic Analysis of Extracellular Vesicles from the Cereal Fungal Pathogen Fusarium graminearum

Fusarium graminearum (F. graminearum) is a filamentous fungus that infects cereals such as corn, wheat, and barley, with serious impact on yield as well as quality when the grain is contaminated with mycotoxins. Despite the huge impact of F. graminearum on food security and mammalian health, the mechanisms used by F. graminearum to export virulence factors during infection are not fully understood and may involve non-classical secretory pathways. Extracellular vesicles (EVs) are lipid-bound compartments produced by cells of all kingdoms that transport several classes of macromolecules and are implicated in cell-cell communication. EVs produced by human fungal pathogens carry cargo that facilitate infection, leading us to ask whether plant fungal pathogens also deliver molecules that increase virulence via EVs. We examined the metabolome of the EVs produced by F. graminearum to determine whether they carry small molecules that could modulate plant-pathogen interactions. We discovered that EVs from F. graminearum were produced in liquid medium-containing inducers of trichothecene production, but in lower quantities compared to other media. Nanoparticle tracking analysis and cryo-electron microscopy revealed that the EVs were morphologically similar to EVs from other organisms; hence, the EVs were metabolically profiled using LC-ESI-MS/MS. This analysis revealed that EVs carry 2,4-dihydroxybenzophenone (BP-1) and metabolites that have been suggested by others to have a role in host-pathogen interactions. BP-1 reduced the growth of F. graminearum in an in vitro assay, suggesting that F. graminearum might use EVs to limit metabolite self-toxicity.