The fate of deoxynivalenol and ochratoxin A during the breadmaking process, effects of sourdough use and bran content

Isotopic, mycotoxin, and pesticide analysis for organic authentication along the production chain of wheat-derived products

Wheat-based products are staples in diets worldwide. Organic food frauds continuously threaten consumer trust in the agri-food system. A multi-method approach was conducted for the organic authentication and safety assessment of pasta and bakery products along their production chain. Bulk and Compound-Specific (CS) Isotope Ratio Mass Spectrometry (IRMS) suggested the δ15Nbulk, δ15Nleucine and δ15Nproline as promising organic markers, with CS able to distinguish between pairs which bulk analysis could not. Processing significantly affected the values of δ15Nleucine, δ13Cproline and δ13Cleucine. Multi-mycotoxin analysis (HT-2, T-2, DON, ZEN, OTA, AFB1) revealed higher contamination in conventional than organic samples, while both milling and baking significantly reduced mycotoxin content. Lastly, from the evaluation of 400 residues, isopyrazam was present at the highest concentration (0.12 mg/kg) in conventional wheat, exhibiting a 0.12 Processing Factor (PF), while tebuconazole levels remained unchanged in pasta production (90 °C) and reduced below LOQ in biscuits and crackers (180-250 °C).

Aflatoxin B1 and ochratoxin A reduction by Lactobacillus spp. during bread making

BACKGROUND

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are among the most important mycotoxins with common presence in bread and bakery products. Biological detoxification of mould food spoilage and mycotoxin contamination by lactic acid bacteria (LABs) exhibits high potential on a cost-effective and large scale. In this work, the effect of Lactobacillus strains isolated from goat milk whey on reducing AFB1 and OTA during bread making was evaluated by the determination of mycotoxin reduction potential of 12 LAB strains after 72 h incubation in De Man-Rogosa-Sharpe (MRS) broth (37 °C). The most effective LABs were lyophilized and added as ingredient in bread formulation, analysing mycotoxins by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry after bread fermentation and baking.

RESULTS

AFB1 was reduced in MRS broth by seven LABs (11-35%), highlighting Lactobacillus plantarum B3 activity; while all LABs reduced OTA (12-40%) with L. plantarum B3 and Lactobacillus paracasei B10 as the most active strains. Both LABs were lyophilized and added in contaminated bread with and without yeast, reaching AFB1 and OTA reductions up to 27% and 32% respectively in dough and up to 55% and 34% respectively in bread.

CONCLUSION

The selected strains significantly reduced AFB1 and OTA during bread fermentation, pointing to a potential biocontrol strategy for mycotoxins detoxification in bread and bakery products. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Does sourdough bread provide clinically relevant health benefits?

During the last decade, scientific interest in and consumer attention to sourdough fermentation in bread making has increased. On the one hand, this technology may favorably impact product quality, including flavor and shelf-life of bakery products; on the other hand, some cereal components, especially in wheat and rye, which are known to cause adverse reactions in a small subset of the population, can be partially modified or degraded. The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.

Matrix-associated mycotoxins in foods, cereals and feedstuffs: A review on occurrence, detection, transformation and future challenges

Matrix-associated mycotoxins that bind with macromolecular components through covalent or non-covalent interactions easily occur in various cereals, cereal-based products, and cereal-based feedstuff. They are "masked" by macro-components, causing the underestimation of total exposure risk of mycotoxins. Most of the current reports focus on the free and modified mycotoxins, while the matrix-associated forms are ignored but still can exert toxic effects after ingestion. In this paper, current researches and future prospects of matrix-associated mycotoxins are reviewed. Especially, a focus is set on the transformation of matrix-associated mycotoxins with their free forms during metabolism and food processing. Enzymes, temperature and pH levels during food processing can induce the interconversion of matrix-associated mycotoxins with free mycotoxins. Furthermore, the analytical methods targeted on matrix-associated mycotoxins are discussed. Due to the lack of efficient methods releasing the mycotoxins from matrix, the standard analytical methods has not developed so far. Also, we further analyzed the challenges of matrix-associated mycotoxins about variety, occurrence, toxicity and transformation, exposure assessment, which contributes to establish preventive measures to control their hazards for consumers. Overall, this overview is significant for perfecting risk assessment, as well as developing effective prevention and control actions to matrix-associated mycotoxins.

A Novel Fluorescent Aptasensor Based on Real-Time Fluorescence and Strand Displacement Amplification for the Detection of Ochratoxin A

It is urgently necessary to develop convenient, reliable, ultrasensitive and specific methods of ochratoxin A determination in food safety owing to its high toxicity. In the present study, an ultrasensitive and labeled-free fluorescent aptamer sensor combining real-time fluorescence with strand displacement amplification (SDA) was fabricated for the determination of OTA. In the presence of OTA, the OTA–aptamer combines with OTA, thus opening hairpins. Then, SDA primers specifically bind to the hairpin stem, which is used for subsequent amplification as a template. SDA amplification is initiated under the action of Bst DNA polymerase and nicking endonuclease. The amplified products (ssDNA) are dyed with SYBR Green II and detected with real-time fluorescence. The method has good linearity in the range of 0.01–50 ng mL⁻¹, with the lowest limit of detection of 0.01 ng mL⁻¹. Additionally, the fluorescent aptamer sensor shows outstanding specificity and reproducibility. Furthermore, the sensor shows excellent analytical performance in the artificial labeled detection of wheat and oat samples, with a recovery rate of 96.1~100%. The results suggest that the developed sensor has a promising potential application for the ultrasensitive detection of contaminants in food.

Deoxynivalenol: An Overview on Occurrence, Chemistry, Biosynthesis, Health Effects and Its Detection, Management, and Control Strategies in Food and Feed

Mycotoxins are fungi-produced secondary metabolites that can contaminate many foods eaten by humans and animals. Deoxynivalenol (DON), which is formed by Fusarium, is one of the most common occurring predominantly in cereal grains and thus poses a significant health risk. When DON is ingested, it can cause both acute and chronic toxicity. Acute signs include abdominal pain, anorexia, diarrhea, increased salivation, vomiting, and malaise. The most common effects of chronic DON exposure include changes in dietary efficacy, weight loss, and anorexia. This review provides a succinct overview of various sources, biosynthetic mechanisms, and genes governing DON production, along with its consequences on human and animal health. It also covers the effect of environmental factors on its production with potential detection, management, and control strategies.

Effect of Popcorn (Zea mays var. everta) Popping Mode (Microwave, Hot Oil, and Hot Air) on Fumonisins and Deoxynivalenol Contamination Levels

Mycotoxins are secondary metabolites that are produced by molds during their development. According to fungal physiological particularities, mycotoxins can contaminate crops before harvest or during storage. Among toxins that represent a real public health issue, those produced by Fusarium genus in cereals before harvest are of great importance since they are the most frequent in European productions. Among them, deoxynivalenol (DON) and fumonisins (FUM) frequently contaminate maize. In recent years, numerous studies have investigated whether food processing techniques can be exploited to reduce the levels of these two mycotoxins, which would allow the identification and quantification of parameters affecting mycotoxin stability. The particularity of the popcorn process is that it associates heat treatment with a particular physical phenomenon (i.e., expansion). Three methods exist to implement the popcorn transformation process: hot air, hot oil, and microwaves, all of which are tested in this study. The results show that all popping modes significantly reduce FUM contents in both Mushroom and Butterfly types of popcorn. The mean initial contamination of 1351 µg/kg was reduced by 91% on average after popping. For DON, the reduction was less important despite a lower initial contamination than for FUM (560 µg/kg). Only the hot oil popping for the Mushroom type significantly reduced the contamination up to 78% compared to unpopped controls. Hot oil popping appears to provide the most important reduction for the two considered mycotoxins for both types of popcorn (−98% and −58% average reduction for FUM and DON, respectively).

Impact of experimental thermal processing of artificially contaminated pea products on ochratoxin A and phomopsin A

Fungi of Aspergillus and Penicillium genus can infect peas (Pisum sativum), leading to a contamination with the nephrotoxic and carcinogenic ochratoxin A (OTA). Under unfavourable conditions, a fungus primarily found on lupines, Diapothe toxica, may also grow on peas and produce the hepatotoxic phomopsin A (PHOA). To study the effect of processing on OTA and PHOA content, two model products-wheat/rye-mixed bread with pea flour addition and pea pasta-were manufactured at small-business scale from artificially contaminated pea flour. The decrease of OTA and PHOA contents were monitored along the production process as indicators for toxin transformation. Pea bread dough was subjected to proofing for 30-40 min at 32 °C and baked at 250 °C to 230 °C for 40 min. OTA content (LODs < 0.1 μg/kg) showed a reduction in the bread crust (initially 17.0 μg/kg) to 88% and no reduction in the crumb (110%). For PHOA (LODs < 3.6 μg/kg), a decrease to approximately 21% occurred in the bread crust (initially 12.5 μg/kg), whilst for crumb, a less intense decrease to 91% was found. Pea pasta prepared with two toxin levels was extruded at room temperature, dried and cooked for 8 min in boiling water. In pea pasta, OTA was reduced from 29.8 to 13.9 μg/kg by 22% each after cooking, whilst 15% and 10% of the initial toxin amounts were found in the cooking water, respectively. For PHOA, 60% and 78% of initially 14.3 μg/kg and 7.21 μg/kg remained in the cooked pasta. As only the decrease of the initial content was measured and no specific degradation products could be detected, further research is needed to characterise potential transformation products. Heat treatment reduces the initial PHOA content stronger than the OTA content during pasta cooking and bread making. However, significant amounts of both toxins would remain in the final products.

Cascade strand displacement reaction-assisted aptamer-based highly sensitive detection of ochratoxin A

Ochratoxin A (OTA) is a toxic metabolite that is widely distributed in food products. Herein, we proposed a new fluorescent aptasensor for OTA detection by using cascade strand displacement reaction. The binding of OTA and OTA aptamer on magnetic beads surface inhibited its hybridization with complementary DNA, and subsequently initiated the strand displacement reaction that induced amplified fluorescence signal. By tracing fluorescence response, our method demonstrated an improved detection limit of 0.63 ng/mL, a short assay time of 110 min, and a satisfactory detection specificity by using ochratoxin B, aflatoxin B1, and zearalenone as control toxins. Recovery studies were conducted by spiking OTA in real food samples, including white wine, red wine, cereal drink, coffee beverage and tea beverage, and confirmed desirable accuracy and practical applicability of our method. Therefore, our method may have a great potential use in the food quality control in the future.

Transformations of Selected Fusarium Toxins and Their Modified Forms During Malt Loaf Production

An increasing number of studies have found that modified mycotoxins, such as free mycotoxins, naturally occur in food, and severely impact food safety. The present study investigated concentrations of trichothecenes nivalenol (NIV), deoxynivalenol (DON), and zearalenone (ZEN), together with their modified forms, nivalenol-3-glucoside (NIV-3G), deoxynivalenol-3-glucoside (DON-3G), and zearalenone-14-glucoside (ZEN-14G) and zearalenone-14-sulfate (ZEN-14S), respectively, at successive stages of malt loaf production (flour, dough kneading/fermentation, loaf baking). Toxins in bakery products originate in flour produced from wheat grain that is naturally contaminated with Fusarium culmorum. Mycotoxin concentrations were determined using high-performance liquid chromatography-high resolution mass spectrometry, and did not significantly change during the successive stages of bread production. After the dough kneading/fermentation stage, concentrations of NIV-3G and DON-3G were slightly increased, whereas those of ZEN and ZEN-14S were slightly decreased. The largest average decrease (21%) was found in ZEN-14G. After the baking stage, the average concentrations of NIV-3G, DON-3G, ZEN-14S, and ZEN-14G in the loaf crumb and crust decreased by 23%, 28%, 27%, and 20%, respectively, compared with those in the dough. During this technical process, the concentration of ZEN-14G in loaf crumb significantly decreased by an average of 48%, and those of ZEN, ZEN-14S, and ZEN-14G in loaf crust decreased by an average of 29%, 42%, and 48%, respectively. Considering the possibility of modified mycotoxins degradation to free forms, as well as the ability to synthesize them from free forms during technological processes, it would be prudent to consider them together during analysis.

Occurrence and preventive strategies to control mycotoxins in cereal-based food

Mycotoxins contamination in cereal-based food is ubiquitous according to systematic review of the scientific documentation of worldwide mycotoxin contamination in cereal and their products between 2008 and 2018, thus representing food safety issue especially in developing tropical countries. Food processing plays a vital role to prevent mycotoxin contamination in food. Therefore, it is with great urgency to develop strategies to inhibit fungi growth and mycotoxin production during food processing. This review begins by discussing physicochemical properties of five most common mycotoxins (aflatoxins, fumonisins, ochratoxins, deoxynivalenol, and zearalenone) found in cereal grains, regulation for mycotoxins in food, and their potential negative impact on human health. The fate of mycotoxins during major cereal-based food processing including milling, breadmaking, extrusion, malting, and brewing was then summarized. In the end, traditional mitigation strategies including physical and chemical and potential application of biocontrol agent and essential oil nanoemulsions that can be applied during food processing were discussed. It indicated that no single method is currently available to completely prevent mycotoxin contamination in cereal foods.

Occurrence of the Ochratoxin A Degradation Product 2'R-Ochratoxin A in Coffee and Other Food: An Update

Food raw materials can contain the mycotoxin ochratoxin A (OTA). Thermal processing of these materials may result in decreased OTA levels but also in the formation of the thermal isomerization product 2′R-ochratoxin A (2′R-OTA). So far, only 2′R-OTA levels reported from 15 coffee samples in 2008 are known, which is little when compared to the importance of coffee as a food and trading good. Herein, we present results from a set of model experiments studying the effect of temperatures between 120 °C and 270 °C on the isomerization of OTA to 2′R-OTA. It is shown that isomerization of OTA starts at temperatures as low as 120 °C. At 210 °C and above, the formation of 25% 2′R-OTA is observed in less than one minute. Furthermore, 51 coffee samples from France, Germany, and Guatemala were analyzed by HPLC-MS/MS for the presence of OTA and 2′R-OTA. OTA was quantified in 96% of the samples, while 2′R-OTA was quantifiable in 35% of the samples. The highest OTA and 2′R-OTA levels of 28.4 µg/kg and 3.9 µg/kg, respectively, were detected in coffee from Guatemala. The OTA:2′R-OTA ratio in the samples ranged between 2.5:1 and 10:1 and was on average 5.5:1. Besides coffee, 2′R-OTA was also for the first time detected in a bread sample and malt coffee powder.

The influence of yeast level and fermentation temperature on Ochratoxin A decrement during bread making

Ochratoxin A (OTA) occurrence in cereals is a permanent challenge in human health. In recent years, some studies have focused on the role of yeasts as adsorbing tools to eliminate OTA. The aim of the current research was to study the effects of different variables including Saccharomyces cerevisiae amount and the fermentation temperature on the reduction of OTA during bread baking. For this purpose, the OTA was spiked to the flour and then the bread was prepared. OTA levels in flour, dough, and bread were measured by the high-performance liquid chromatography with fluorescence detector (HPLC-FD). The results revealed that yeast level and fermentation temperature had a significant effect on OTA reduction. The increase of the amount of S. cerevisiae from 1% to 2% w/w and the fermentation temperature from 25ºC to 30ºC resulted in the increment of OTA reduction from 31.17% to 59.41%. During baking, OTA reduction was 19.21%. In general, the utilization of 2% w/w S. cerevisiae and the fermentation temperature of 35 ºC could reduce considerable amount of OTA in the wheat bread.

Changes in masked forms of deoxynivalenol and their co-occurrence with culmorin in cereal-based products: A systematic review and meta-analysis

This study was aimed to evaluate the fate of D3G, 3-ADON, and 15-ADON during various processing steps (milling, fermentation, baking and cooking with water) of different cereal-based products, as well as the co-occurrence of culmorin (CUL) and its derivatives (15-Hydroxy-CUL and 5-Hydroxy-CUL. Some databases such as Science Direct, PubMed, Scopus, and Embase were screened to collect the relevant published papers between January 1983 to October 2018, and 23 articles with 319 data were included. The baking resulted in reductions in the concentration of all types of investigated masked mycotoxins, i.e., 15-ADON (-25%) > 3-ADON (-15%) > D3G (-6%). Also, rank order of CUL and its derivatives based on occurrence was CUL (70%) > 15-Hydroxy-CUL (47%) > 5-Hydroxy-CUL (15%) and their rank based on their concentration was 5-Hydroxy-CUL (99.21 µg/kg) > CUL (48.84 µg/kg) > 15-Hydroxy-CUL (9.39 µg/kg) > Hydroxy -CUL (0.06 µg/kg) > 12-Hydroxy-CUL (0.05 µg/kg) > 14-Hydroxy-CUL (0.01 µg/kg).

Fate of Fusarium mycotoxins during processing of Nigerian traditional infant foods (ogi and soybean powder)

The influence of processing methods used to produce traditional Nigerian infant foods (ogi and processed soybean powder) on four European Union regulated Fusarium mycotoxins using naturally and artificially contaminated raw materials was studied using liquid chromatography-tandem mass spectrometry. Generally, there was a significant reduction of all the mycotoxins when compared to the initial concentration of the raw materials. Reduction in concentrations of the mycotoxins during ogi-processing started immediately after 36 h' steeping/fermentation for all the mycotoxins (fumonisin B1, zearalenone, deoxynivalenol, and T-2 toxin), and proceeded along the process chain (milling and sieving). In addition, deoxynivalenol-3-glucoside (16 ± 3.2 μg/kg) and 3-acetyl-deoxynivalenol (9 ± 5.5 μg/kg) initially absent in the raw maize were detected in the final ogi product. β-zearalenol, hydrolysed fumonisin B1, and HT-2 toxin were also detected at varying concentrations. Regarding soybean processing, a similar trend was observed with fumonisin B1, zearalenone, deoxynivalenol, and T-2 toxin, irrespective of the method used or the initial concentration. Other mycotoxins detected in soybean product include 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, deoxynivalenol-3-glucoside, HT-2 toxin, neosolaniol, α-zearalenol, β-zearalenol, and zearalenone-14-glucoside. Although there was a reduction in the concentration of the free mycotoxin because of processing, other mycotoxins were detected in the products and thus, may present an additional health risk on consumers.

Industrial production of sourdoughs for the baking branch - An overview

Sourdoughs are produced both in artisanal and industrial size. Sourdough manufacturers deliver the baking branch either with starters for production of in-house sourdoughs or with fully fermented sourdough products. In the latter case sourdough production is separated in time and space from the bread production. A big part of this convenience products are dried sourdoughs, which are mainly produced from rye and wheat flour, but also from other starch containing plants, like pseudocereals or legumes. The requirements regarding the raw materials used differ from that used for baking bread. The most applied drying techniques for sourdoughs are drum and spray-drying. Compared with other foods, sourdough and sourdough products have only a low risk regarding food safety due to pH < 4.2, however formation of biogenic amines or acrylamide has taken into account. More tools for sourdough authentication are needed but, before developing and validating methods, it would be necessary to include different sourdough products in a clear regulatory framework.

The Fate of Mycotoxins During the Processing of Wheat for Human Consumption

Mycotoxins are a potential health threat in cereals including wheat. In the European Union (EU), mycotoxin maximum levels are laid down for cereal raw materials and final food products. For wheat and wheat-based products, the EU maximum levels apply to deoxynivalenol (DON), zearalenone, aflatoxins, and ochratoxin A. This review provides a comprehensive overview on the different mycotoxins and their legal limits and on how processing of wheat can affect such contaminants, from raw material to highly processed final products, based on relevant scientific studies published in the literature. The potential compliance with EU maximum levels is discussed. Of the four mycotoxins regulated in wheat-based foods in the EU, most data are available for DON, whereas aflatoxins were rarely studied in the processing of wheat. Furthermore, available data on the effect of processing are outlined for mycotoxins not regulated by EU law-including modified and emerging mycotoxins-and which cover DON derivatives (DON-3-glucoside, mono-acetyl-DONs, norDONs, deepoxy-DON), nivalenol, T-2 and HT-2 toxins, enniatins, beauvericin, moniliformin, and fumonisins. The processing steps addressed in this review cover primary processing (premilling and milling operations) and secondary processing procedures (such as fermentation and thermal treatments). A special focus is on the production of baked goods, and processing factors for DON in wheat bread production were estimated. For wheat milling products derived from the endosperm and for white bread, compliance with legal requirements seems to be mostly achievable when applying good practices. In the case of wholemeal products, bran-enriched products, or high-cereal low-moisture bakery products, this appears to be challenging and improved technology and/or selection of high-quality raw materials would be required.

Mold spoilage of bread and its biopreservation: A review of current strategies for bread shelf life extension

Microbial spoilage of bread and the consequent waste problem causes large economic losses for both the bakery industry and the consumer. Furthermore the presence of mycotoxins due to fungal contamination in cereals and cereal products remains a significant issue. The use of conventional chemical preservatives has several drawbacks, necessitating the development of clean-label alternatives. In this review, we describe current research aiming to extend the shelf life of bread through the use of more consumer friendly and ecologically sustainable preservation techniques as alternatives to chemical additives. Studies on the in situ-production/-expression of antifungal compounds are presented, with special attention given to recent developments over the past decade. Sourdough fermented with antifungal strains of lactic acid bacteria (LAB) is an area of increasing focus and serves as a high-potential biological ingredient to produce gluten-containing and gluten-free breads with improved nutritional value, quality and safety due to shelf-life extension, and is in-line with consumer's demands for more products containing less additives. Other alternative biopreservation techniques include the utilization of antifungal peptides, ethanol and plant extracts. These can be added to bread formulations or incorporated in antimicrobial films for active packaging (AP) of bread. This review outlines recent progress that has been made in the area of bread biopreservation and future perspectives in this important area.

Occurrence and risk assessment of population exposed to deoxynivalenol in foods derived from wheat flour in Brazil

Deoxynivalenol (DON) is the most important of the trichothecenes in terms of amounts and occurrence in wheat. This compound was shown to be associated with a glomerulonephropathy involving an increase of immunoglobulin A in humans. This study assessed the occurrence of DON in wheat flour and the exposure of Brazilian teenagers, adults and elderly to this mycotoxin due to intake of wheat flour-based products. DON extraction in wheat flour was carried out by solid phase extraction and the quantification was performed by ultra-high proficiency liquid chromatography with diode-array detection. A total of 77.9% of all samples were positive for DON, with concentrations ranging from 73.50 to 2794.63 µg kg^-1. The intake was calculated for the average and 90th percentile of the contamination levels of DON in foods based-wheat for teenagers, adults and elderly in Brazil, and compared with the provisional maximum tolerable daily intakes (PMTDI). Females of all age groups were exposed to DON at higher levels when compared to males in regard of consumption of breads and pastas. Teenagers were the main consumers of foods derived from wheat flour, with maximum probable daily intakes of 1.28 and 1.20 µg kg^-1 b.w. day^-1 for females and males, respectively. This population is at an increased risk of exposure to DON due to consumption of wheat flour-based foods in Brazil.

Deoxynivalenol and its acetyl derivatives in bread and biscuits in Shandong province of China

In the present study, 100 commercial breads and biscuits were investigated for the occurrence of deoxynivalenol (DON) and its acetylated derivatives 3-acetyldeoxynivalenol (3-Ac-DON) and 15-acetyldeoxynivalenol (15-Ac-DON). The target mycotoxins were determined by isotope dilution ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). DON was determined in 95% of the test samples with a mean value of 153.3 µg/kg. Compared with DON, 3-Ac-DON and 15-Ac-DON were far less frequently detected, with mean values of 1.14 and 0.37 µg/kg, respectively. The estimated daily intakes of the sum of DON and its derivatives in breads and biscuits were 0.0059 and 0.0313 µg/kg bw/day, respectively, which was within the group provisional tolerable daily intake of 1.0 µg/kg bw/day set by the Joint FAO/WHO Expert Committee on Food Additives. In the future, systematic monitoring programmes of DON and its derivatives in relevant foodstuffs are still necessary for food safety and human health.

Effect of xylanase and α-amylase on DON and its conjugates during the breadmaking process

Deoxynivalenol (DON) is one of the most frequently occurring mycotoxins in wheat crops worldwide and poses a risk to human and animal health due to its wide range of adverse effects. Deoxynivalenol-3-glucoside (DON-3-glucoside) is a DON plant conjugate that is widely found in cereal products. As DON accumulation in the field seems unavoidable, it is important to investigate all of the conditions that affect its stability during food processing. One of the most consumed cereal product around the world is bread, however the published information about DON stability in bread shows a large variability of results because a huge amount of factors affect DON and its modified forms. So, the aim of this research was to study the fate of DON and its modified forms through the breadmaking process with the addition of xylanase and α-amylase at different fermentation temperatures. Moreover, different α-amylase and xylanase concentrations were added to the dough to be fermented. To quantify DON and its derived forms in the samples, liquid chromatography with double mass spectrophotometer was used. DON was reduced during fermentation and baking; however, the reduction at each step was related to the fermentation temperature. The presence of α-amylase and xylanase caused increases in DON during fermentation and during early baking. DON-3-glucoside was slightly reduced after fermentation and was widely increased (>80%) after baking. Deepoxy-deoxynivalenol (DOM-1) increased during the breadmaking process. Breadmaking process can reduce DON concentration, however xylanase and α-amylase presence cause increases of DON.

Fate of deoxynivalenol and deoxynivalenol-3-glucoside during cereal-based thermal food processing: a review study

Deoxynivalenol (DON), the most commonly occurring trichothecene in nature, may affect animal and human health through causing diarrhea, vomiting, gastrointestinal inflammation, and immunomodulation. DON-3-glucoside (DON-3G) as a major plant metabolite of the mycotoxin is another "emerging" food safety issue in recent years. Humans may experience potential health risks by consuming DON-contaminated food products. Thus, it is crucial for human and animal health to study also the degradation of DON and DON-3G during thermal food processing. Baking, boiling, steaming, frying, and extrusion cooking are commonly used during thermal food processing and have promising effects on the reduction of mycotoxins in food. For DON, however, the observed effects of these methods, as reported in numerous studies, are ambiguous and do not present a clear picture with regard to reduction or transformation. This review summarized the influence of thermal processing on the stability of DON and the formation of degradation/conversion products. Besides this, also a release of DON and DON-3G from food matrix as well as the release of DON from DON-3G during processing is discussed. In addition, some conflicting findings as reported from the studies on thermal processing as well as cause-effect relationships of the different thermal procedures are explored. Finally, the potential toxic profiles of DON degradation products are discussed as well when data are available.

Strategies for estimating human exposure to mycotoxins via food

In this review, five strategies to estimate mycotoxin exposure of a (sub-)population via food, including data collection, are discussed with the aim to identify the added values and limitations of each strategy for risk assessment of these chemicals. The well-established point estimate, observed individual mean, probabilistic and duplicate diet strategies are addressed, as well as the emerging human biomonitoring strategy. All five exposure assessment strategies allow the estimation of chronic (long-term) exposure to mycotoxins, and, with the exception of the observed individual mean strategy, also acute (short-term) exposure. Methods for data collection, i.e. food consumption surveys, food monitoring studies and total diet studies are discussed. In food monitoring studies, the driving force is often enforcement of legal limits, and, consequently, data are often generated with relatively high limits of quantification and targeted at products suspected to contain mycotoxin levels above these legal limits. Total diet studies provide a solid base for chronic exposure assessments since they provide mycotoxin levels in food based on well-defined samples and including the effect of food preparation. Duplicate diet studies and human biomonitoring studies reveal the actual exposure but often involve a restricted group of human volunteers and a limited time period. Human biomonitoring studies may also include exposure to mycotoxins from other sources than food, and exposure to modified mycotoxins that may not be detected with current analytical methods. Low limits of quantification are required for analytical methods applied for data collection to avoid large uncertainties in the exposure due to high numbers of left censored data, i.e. with levels below the limit of quantification.

Impact of food processing and detoxification treatments on mycotoxin contamination

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

Ochratoxin A activates neutrophils and kills these cells through necrosis, an effect eliminated through its conversion into ochratoxin α

Ochratoxin A (OTA) is a mycotoxin produced by several species of fungi from the Aspergillus and Penicillium genera that frequently grow in improperly stored food products. OTA has carcinogenic, teratogenic and nephrotoxic potential and sustains a high half-life in human blood. Despite the recently efforts to decontaminate OTA through its conversion into its metabolite ochratoxin alpha (OTα), there are just a few reports in literature comparing the toxic effects of these toxins. Thus, herein we studied and compared the proinflammatory and toxicological effects of OTA and its metabolite OTα in human neutrophils in vitro. The effect of OTA and OTα on human neutrophils viability was evaluated by trypan blue, annexin-V and propidium iodide methods as well as by the analysis of cytomorphological alterations. The ATP levels were also evaluated using the luciferin-luciferase bioluminescence assay. The alteration on mitochondrial potential was assessed by a mitoscreen flow cytometry mitochondrial membrane potential detection kit and the intracellular calcium levels through the probe FLUO-4/AM. To study the human neutrophils' oxidative burst, the fluorescent probe dichlorodihydrofluorescein diacetate was used. OTA induced an increase on the intracellular calcium, human neutrophils' oxidative burst followed by depletion of ATP levels and alterations on mitochondrial potential leading to cell death by necrosis, while OTα did not induce significant toxic effects. Our results strongly suggest that the toxicity in human neutrophils induced by OTA started with the release of calcium from internal stores triggering several neutrophils' activities that culminate in cell death by necrosis.

Deoxynivalenol & Deoxynivalenol-3-Glucoside Mitigation through Bakery Production Strategies: Effective Experimental Design within Industrial Rusk-Making Technology

In the scientific field, there is a progressive awareness about the potential implications of food processing on mycotoxins especially concerning thermal treatments. High temperatures may cause, in fact, transformation or degradation of these compounds. This work is aimed to study the fate of mycotoxins during bakery processing, focusing on deoxynivalenol (DON) and deoxynivalenol-3-glucoside (DON3Glc), along the chain of industrial rusk production. Starting from naturally contaminated bran, we studied how concentrations of DON and DON3Glc are influenced by modifying ingredients and operative conditions. The experiments were performed using statistical Design of Experiment (DoE) schemes to synergistically explore the relationship between mycotoxin reduction and the indicated processing transformation parameters. All samples collected during pilot plant experiments were analyzed with an LC-MS/MS multimycotoxin method. The obtained model shows a good fitting, giving back relevant information in terms of optimization of the industrial production process, in particular suggesting that time and temperature in baking and toasting steps are highly relevant for minimizing mycotoxin level in rusks. A reduction up to 30% for DON and DON3Glc content in the finished product was observed within an acceptable technological range.

Thermal stability and kinetics of degradation of deoxynivalenol, deoxynivalenol conjugates and ochratoxin A during baking of wheat bakery products

The stability of deoxynivalenol (DON), deoxynivalenol-3-glucoside (DON-3-glucoside), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), de-epoxy-deoxynivalenol (DOM-1) and ochratoxin A (OTA) during thermal processing has been studied. Baking temperature, time and initial mycotoxin concentration in the raw materials were assayed as factors. An improved UPLC-MS/MS method to detect DON, DON-3-glucoside, 3-ADON, 15-ADON and DOM-1 in wheat baked products was developed in the present assay. The results highlighted the importance of temperature and time in mycotoxin stability in heat treatments. OTA is more stable than DON in a baking treatment. Interestingly, the DON-3-glucoside concentrations increased (>300%) under mild baking conditions. On the other hand, it was rapidly reduced under harsh conditions. The 3-ADON decreased during the heat treatment; while DOM-1 increased after the heating process. Finally, the data followed first order kinetics for analysed mycotoxins and thermal constant rates (k) were calculated. This parameter can be a useful tool for prediction of mycotoxin levels.

Sourdough lactic acid bacteria as antifungal and mycotoxin-controlling agents

Sourdough starter cultures are rich sources of endogenous lactic acid bacteria. The extended shelf lives of sourdough breads are attributed to a large array of organic acids and low-molecular-weight metabolites produced during the fermentation process. Different species belonging to the lactic acid bacteria group of microorganisms, mainly Lactobacillus and Leuconostoc, are increasingly gaining the attention as possible means for inhibiting mold growth in animal feed and human food chains. In addition, certain lactic acid bacteria strains isolated from sourdough starters were also shown to reduce mycotoxins concentrations in contaminated products either by binding or degradation. This short review will summarize the findings in this context that pertain to lactic acid bacteria isolated specifically from sourdough starters and acquaint the reader with the most recent advancements in this bio-preservation trend.