Transformation of deoxynivalenol and its acetylated derivatives in Chinese steamed bread making, as affected by pH, yeast, and steaming time

Assessment of group B trichothecene contamination in bread: Correlation during breadmaking and simulation of gastrointestinal digestion

This study investigates bioaccessibility and permeation capacity of group B trichothecenes in bread by different parameters of fermentation and baking times. Variables of the experimental design were first fermentation time, second fermentation time and baking time. Results showed that 120-min baking in the 2nd fermentation reduced Nivalenol (NIV), 15-acetyl-deoxynivalenol (15-AcDON) and deoxynivalenol-3-glucoside (DON-3G), whereas 30-min baking increased NIV. In the gastric stage, Deoxynivalenol (DON) and 3-acetyl-deoxynivalenol (3-AcDON) bioaccessibility increased, while DON-3G and 15-AcDON were undetected. In the intestinal stage, high DON-3G levels were detected, but NIV was undetected. Bioaccessible 15-AcDON was correlated with the 1st fermentation time. Permeation rates were 100 % and 91 % in the cases of DON and DON-3G, respectively. This study reinforced the interconvertibility of group B trichothecene forms during bread making and digestion. Merely assessing contaminant concentrations in the final product is not suitable to reflect trichothecene exposure.

Distribution and safety evaluation of deoxynivalenol and its derivatives throughout the wheat product processing chain

The distribution of deoxynivalenol (DON) and its derivatives 3-acetyldeoxynivalenol (3-Ac-DON) and 15-acetyldeoxynivalenol (15-Ac-DON) throughout the wheat processing chain were systemically evaluated by one-to-one corresponding studies of the whole processing chain. DON and its derivatives were determined by liquid chromatography-mass spectrometry (LC-MS/MS) in wheat grains and corresponding wheat bran, wheat flour, and semi-finished and finished wheat flour-based products. This investigation showed that wheat grain processing to wheat flour significantly decreased the levels of DON by approximately 52.7%-68.2%. Wheat flour processing of wheat flour-based products decreased the DON concentration by approximately 7.0%-70.6%. Among the processing methods, biscuit making showed the largest reduction (70.6%). The co-occurrence frequency of DON with low levels of 3-Ac-DON and 15-Ac-DON was significantly greater in wheat grains and wheat bran than in wheat flour. For wheat flour-based products, only the distribution pattern of 3-Ac-DON was observable in processed wheat flour products prepared using grains heavily contaminated with DON. In China, to the best of our knowledge, the processing factors (PFs) of DON in wheat flour and wheat flour-based products were systematically evaluated for the first time. The average PF of DON was 0.35 for wheat flour and the average PFs were 0.37-0.84 for wheat flour-based products, with biscuits having the smallest PF (0.37), indicating DON significantly decreasing in biscuit making. Furthermore, dietary exposure assessment of DON indicated an acceptable overall health risk in Chinese consumers, with the highest exposure being observed in infants and young children. This study provides important references for classified management of DON limits in wheat and its various products in China.

Profiles of Sterigmatocystin and Its Metabolites during Traditional Chinese Rice Wine Processing

Mycotoxin pollution is widespread in cereal, which greatly threatens food security and human health. In this study, the migration and transformation of sterigmatocystin (STG) mycotoxin during the contaminated rice wine processing was systematically assessed. QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) coupled with ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UPLC−MS/MS) method was firstly established for STG analysis in rice wine. It was found that high levels of rice leaven caused a significant reduction in STG in the fermented rice and wine, which was mainly due to the adsorption of yeast cells and Rhizopus biological degradation. However, compared with rice, the levels of STG in separated fermented wine was significantly decreased by 88.6%, possibly attributed to its high log Kow (3.81) and low water solubility (1.44 mg/L). The metabolites of STG (i.e., monohydroxy STG) were identified in rice wine fermentation for the first time. Moreover, STG disturbed the metabolic profile rice wine composition mainly by glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism, purine metabolism pathway, particularly with regard to eight amino acids and sixteen lipids. This study elucidated the STG migration and transformation mechanism during the rice wine processing. The finding provided new analytical method for mycotoxin exposure and pollutant in food production, which may support agricultural production and food security.

The effect of technological processes on contamination with B-class trichothecenes and quality of spring wheat products from grain harvested at different times

The study aimed to investigate the effect of technological processes on deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON) concentrations and quality of spring wheat products from grain harvested at different times. In this study, 408 samples were analysed for DON, 3-ADON and 15-ADON contamination by the HPLC method with UV detection. Delays in harvesting due to cool and rainy weather conditions resulted in increased DON, 3-ADON and 15-ADON levels. The highest DON concentrations were determined in bran. Higher DON concentrations in the bran indicate the protective function of the grain hull. On the other hand, the highest levels of minerals have been found in bran and whole grain flours, highlighting the importance of consuming these milling fractions as a mineral source with sustained health benefits. Our results showed that DON is stable at 170 °C, and high DON levels in whole-meal flour and white flour could not be converted or decomposed during baking. The levels of 3-ADON and 15-ADON in whole-meal flour bread and white flour bread were significantly reduced but not completely removed. The levels of DON and its derivatives 3-ADON and 15-ADON were significantly reduced in starch and gluten produced from contaminated whole meal flour; however, the washing process did not completely eliminate these toxic compounds. The concentrations of mycotoxins in starch and gluten remained relatively high. Negative correlation was found in highly contaminated samples between DON and bread baking properties. Also, inverse relationship was found between high mycotoxin concentrations and mineral element content in white flour.

Occurrence and Risk Assessment of Dietary Exposure to Deoxynivalenol in Wheat-Based Products Based Different Wheat-Producing Area for the Inhabitants in Shanghai, China

Deoxynivalenol (DON) is one of the major mycotoxins that contaminate cereals. In this study, we determined the DON level in wheat-based products from Chinese five main production areas collected in Shanghai and calculated the daily intake of DON for inhabitants using the point evaluation and the probabilistic evaluation based on Monte Carlo simulation. The results showed the positive rates of DON in the products were higher than 80.0%, with the concentrations ranging from 41.8 to 1110 µg/kg. The estimated mean daily intakes of DON for 7- to 10-year-old children and adults groups were below 1 µg/kg bw/day, the provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), suggesting no health risks for the consumers. However, the 99th percentiles of dietary DON exposures for children and adults exceeded the PMTDI, indicating adverse health effects might occur if the two groups intake highly contaminated wheat-based products. The potential health risks for the two groups exposed to DON in the wheat-based products from the Middle and Lower Yangtze Valley (MLYV) were higher than those from the other areas in China.

Heat-induced reduction of deoxynivalenol and its modified forms during flaking and cooking of oat

Deoxynivalenol (DON) and its modified forms deoxynivalenol-3-glucoside (DON-3G) and 3-acetyl-deoxynivalenol (3-ADON) are common contaminants in Norwegian oats. In order to provide more information about the fate of these mycotoxins during oat processing, the levels of DON, DON-3G, 3-ADON and the sum of them (total DON) were determined using LC-HRMS/MS at different processing steps. Oat groat was softened by either steaming or conditioning, rolled into flakes of two thicknesses, and subsequently cooked to produce flake porridges. Flour of oat groat (untreated or kilned) was cooked to flour porridges. The flaking process had major effect on the mycotoxin levels in resulting flakes, with significant impact for type of softening regime, but not for flake size. Steam-softening caused the largest reduction of DON, DON-3G and total DON in flakes, retaining 41, 60 and 46%, respectively, compared to oat groat. In contrast, 3-ADON in flakes was most reduced by conditioning, to 29% of the levels in oat groat. Cooking to porridge from flakes did not result in any additional mycotoxin reduction, though significant impact of flake size was shown in the final porridges, with highest reduction of total DON in the porridges originating from steamed thick flakes. Cooking porridge from untreated oat flour gave significant reduction in mycotoxin levels, however not for kilned oat flour which had already undergone reduction during kilning. In conclusion, the study shows that processes involving heat-treatment, i.e. kilning, steaming or cooking, efficiently reduced total DON in oats during flaking and porridge cooking, and reduction is dependent on previous processing steps.

Photocatalysis and degradation products identification of deoxynivalenol in wheat using upconversion nanoparticles@TiO2 composite

Deoxynivalenol (DON) is one of the most common contaminants of cereal grains. Efficient and environmental-friendly technology to eliminate DON is important for food safety and environmental protection. In this work, upconversion nanoparticles (UCNP) coated with titanium dioxide (TiO2) photocatalysts were synthesized. Then, a photocatalytic experiment was performed to test the impact of NaYF4:Yb,Tm@TiO2 of DON degradation. Our results showed the DON degradation rate at 10 μg/mL under simulated sunlight using NaYF4:Yb,Tm@TiO2 (6 mg/mL) approached 100% within 60 min at pH 8.0. UPLC-Q-TOF MS was used to monitor the degradation process and three degradation products were identified, namely C15H20O8, C15H20O7 and C15H20O5. Subsequently, we studied the photocatalytic degradation of DON in wheat, providing a theoretical basis for photocatalytic degradation of contaminated grain samples. This study demonstrated that UCNP@TiO2 photocatalysis has the potential for detoxification in food security applications.

Deacetylation of 3-acetyl-deoxynivalenol in wheat flour is mediated by water-soluble proteins during the making of Chinese steamed bread

To find the determining factors for 3-acetyl-deoxynivalenol (3-ADON) deacetylation during wheat-based food production, wheat flours with different heat treatments, different matrixes of the starch-gluten mixture, and different protein fractions (Osborne classification) were evaluated. The deacetylation behavior of 3-ADON was significantly suppressed for heat-treated wheat flours, indicating that heating induced change of the functional or chemical properties of wheat grain components, especially for proteins. Among the different matrixes, only 3% of the 3-ADON in starch was converted to DON, however, this value reached 60-75% for wheat flour. The results showed that proteins were responsible for the deacetylation of 3-ADON. After separation, only albumins mediated the deacetylation of 3-ADON into DON in four protein fractions. The proteins were identified by LC-MS/MS, and the results suggested that cytochrome P450, acetylesterase and histone deacetylase were the potential targeted enzymes that mediated the deacetylation of 3-ADON during dough preparation for wheat-based food production.

Detoxification of DON by photocatalytic degradation and quality evaluation of wheat

Deoxynivalenol (DON) is regarded as the most common contaminant of cereal grains. Therefore, finding an efficient and safe detoxification technology is of great significance in the field of food. In this study, upconversion nanoparticles@TiO2 composites were used for the photocatalytic degradation of DON in wheat. The effect of photocatalytic oxidation on wheat quality was also evaluated by studying the basic physical and chemical indexes of wheat. The results showed that the removal rate of DON in wheat could reach 72.8% within 90 min when the dosage of photocatalyst UCNP@TiO2 was 8 mg mL-1 and the ratio of wheat to liquid was 1 : 2. In addition, the composites can be easily removed by washing, thus ensuring the low exposure dose of the nanomaterials in wheat. Studies on the nutritional quality of wheat showed that photocatalytic technology had little effect on the starch, protein, amino acid content of wheat (p > 0.05). The whiteness of wheat flour decreased and the yellowness increased. The scanning electron microscopy (SEM) images of wheat starch showed that the surfaces of starch granules were damaged to varying degrees with the prolongation of illumination time. Meanwhile, the fatty acid value and wet gluten content and pasting properties of wheat decreased significantly during photocatalysis (p < 0.05). This study demonstrates that photocatalytic degradation will have a promising prospect in toxin removal.

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).

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.