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.

Root uptake and metabolization of Alternaria toxins by winter wheat plants using a hydroponic system

Fungi of the genus Alternaria are ubiquitous in the environment. Their mycotoxins can leach out of contaminated plants or crop debris into the soil entering the plant via the roots. We aim to evaluate the importance of this entry pathway and its contribution to the overall content of Alternaria toxins (ATs) in wheat plants to better understand the soil-plant-phytopathogen system. A hydroponic cultivation system was established and wheat plants were cultivated for up to two weeks under optimal climate conditions. One half of the plants was treated with a nutrient solution spiked with alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA), whereas the other half of the plants was cultivated without mycotoxins. Plants were harvested after 1 and 2 weeks and analyzed using a QuEChERS-based extraction and an in-house validated LC-MS/MS method for quantification of the ATs in roots, crowns, and leaves separately. ATs were taken up by the roots and transported throughout the plant up to the leaves after 1 as well as 2 weeks of cultivation with the roots showing the highest ATs levels followed by the crowns and the leaves. In addition, numerous AOH and AME conjugates like glucosides, malonyl glucosides, sulfates, and di/trihexosides were detected in different plant compartments and identified by high-resolution mass spectrometry. This is the first study demonstrating the uptake of ATs in vivo using a hydroponic system and whole wheat plants examining both the distribution of ATs within the plant compartments and the modification of ATs by the wheat plants.

Updated Review of the Toxicity of Selected Fusarium Toxins and Their Modified Forms

Mycotoxins are one of the most dangerous food and feed contaminants, hence they have significant influence on human and animal health. This study reviews the information reported over the last few years on the toxic effects of the most relevant and studied Fusarium toxins and their modified forms. Deoxynivalenol (DON) and its metabolites can induce intracellular oxidative stress, resulting in DNA damage. Recent studies have also revealed the capability of DON and its metabolites to disturb the cell cycle and alter amino acid expression. Several studies have attempted to explore the mechanism of action of T-2 and HT-2 toxins in anorexia induction. Among other findings, two neurotransmitters associated with this process have been identified, namely substance P and serotonin (5-hydroxytryptamine). For zearalenone (ZEN) and its metabolites, the literature points out that, in addition to their generally acknowledged estrogenic and oxidative potentials, they can also modify DNA by altering methylation patterns and histone acetylation. The ability of the compounds to induce alterations in the expression of major metabolic genes suggests that these compounds can contribute to the development of numerous metabolic diseases, including type 2 diabetes.

Structural Profiling of Xyloglucans from Food Plants by High-Performance Anion-Exchange Chromatography with Parallel Pulsed Amperometric and Mass Spectrometric Detection

Xyloglucans are the dominant hemicelluloses in the primary cell wall of dicotyledonous plants, fulfilling numerous functions. However, routine methods of cell wall analytical chemistry such as methylation analysis are time-consuming and often not adequate to capture the structural diversity of xyloglucans. Here, a xyloglucan profiling method based on the enzymatic release of xyloglucan oligosaccharides by a xyloglucan-specific endo-β-(1→4)-glucanase and subsequent analysis of these oligosaccharides by high-performance anion-exchange chromatography (HPAEC) with parallel pulsed amperometric and mass spectrometric detection was developed. For this purpose, a set of 23 authentic xyloglucan oligosaccharides was generated, structurally characterized by mass spectrometry and NMR spectroscopy, and established as analytical standard compounds. Coupling of HPAEC with parallel electrochemical and MS detection was demonstrated to be an excellent tool to analyze xyloglucan-derived oligosaccharides. The applicability of the method was demonstrated by characterizing the xyloglucan architecture from a set of nine economically relevant food plants from the botanical orders Caryophyllales (rhubarb, buckwheat, amaranth, and quinoa), Cucurbitales (Hokkaido squash), Laurales (avocado), Myrtales (pomegranate), and Sapindales (mango and orange) for the first time. In future studies, this method can ideally be used to monitor structural alterations of xyloglucans as a result of genetic engineering, plant/tissue maturation, and processing of plant material.