Rapid screening of DON contamination in whole wheat meals by Vis/NIR spectroscopy and computer vision coupling technology

This work intends to develop an online experimental system for screening of deoxynivalenol (DON) contamination in whole wheat meals by visible/near-infrared (Vis/NIR) spectroscopy and computer vision coupling technology. Spectral and image information of samples with various DON levels was collected at speed of 0.15 m s⁻¹ on a conveyor belt. The two-type data were then integrated and subjected to chemometric analysis. Discriminant analysis showed that samples could be classified by setting 1000 μg kg⁻¹ as the cut-off value. The best correct classified rate obtained in prediction was 93.55% based on fusion of spectral and image features, with reduced prediction uncertainty as compared to single feature. However, quantification of DON by quantitative analysis was not successful due to poor model performance. These results indicate that, although not accurate enough to provide conclusive result, this coupling technology could be adopted for rapid screening of DON contamination in cereals and feeds during processing.     

Influence of inoculum and climatic factors on the severity of Fusarium head blight in German spring and winter barley

Fusarium head blight (FHB) of small cereals is a disease of global importance with regard to economic losses and mycotoxin contamination harmful to human and animal health. In Germany, FHB is predominantly associated with wheat and F. graminearum is recognised as the major causal agent of the disease, but little is known about FHB of barley. Monitoring of the natural occurrence of FHB on Bavarian barley revealed differences for individual Fusarium spp. in incidence and severity of grain infection between years and between spring and winter barley. Parallel measurement of fungal DNA content in grain and mycotoxin content suggested the importance of F. graminearum in winter barley and of F. langsethiae in spring barley for FHB. The infection success of these two species was associated with certain weather conditions and barley flowering time. Inoculation experiments in the field revealed different effects of five Fusarium spp. on symptom formation, grain yield and mycotoxin production. A significant association between fungal infection of grain and mycotoxin content was observed following natural or artificial infection with the type B trichothecene producer F. culmorum, but not with the type A trichothecene-producing species F. langsethiae and F. sporotrichioides. Trichothecene type A toxin contamination also occurred in the absence of significant damage to grain and did not necessarily promote fungal colonisation.     

Evaluation of dietary exposure to deoxynivalenol (DON) and its derivatives from cereals in China

Probabilistic estimation of dietary exposure to DON, including its acetylated derivatives, and type B trichothecenes from cereals and cereal-based products in Chinese populations was investigated in the current work. Different cut-offs as proposed Maximum levels (MLs) for DON in various raw cereals and/or cereal-based foods were assessed based on the risk assessment results. Occurrence data was documented from 31 provinces of China over the year 2010–2013. Food consumption data was obtained from the National Diet and Nutrition Survey conducted in 2002. Dietary exposure was implemented by Monte Carlo (MC) simulations and Bootstrap resampling. The exposure distributions were specified as percentiles with confidence intervals (95% CIs) and compared with the group provisional maximum tolerable daily intake (PMTDI) of 1 μg/kg bw/day and the group acute reference dose (ARfD) of 8 μg/kg bw/day for DON and its acetylated derivatives. Results indicate that 75% of children and 90% of the general population and the adults are under the group PMTDI value, while 99% of the three populations are under ARfD value. However, under the assumptions of the proposed cut-offs, the P99.9 percentiles would decrease significantly. The probabilistic assessment in this study indicated that high-end exposure to DON and its derivatives should be concerned, especially for children. Rigorous formulation of maximum limits for DON and its derivatives in the relevant foodstuffs combined with increased monitoring should be considered as an effective way to reduce risk.     

Composition of a protein-like fluorophore of dissolved organic matter in coastal wetland and estuarine ecosystems

This study demonstrates the compositional heterogeneity of a protein-like fluorescence emission signal (T-peak; excitation/emission maximum at 280/325 nm) of dissolved organic matter (DOM) samples collected from subtropical river and estuarine environments. Natural water samples were collected from the Florida Coastal Everglades ecosystem. The samples were ultrafiltered and excitation-emission fluorescence matrices were obtained. The T-peak intensity correlated positively with N concentration of the ultrafiltered DOM solution (UDON), although, the low correlation coefficient (r(2)=0.140, p<0.05) suggested the coexistence of proteins with other classes of compounds in the T-peak. As such, the T-peak was unbundled on size exclusion chromatography. The elution curves showed that the T-peak was composed of two compounds with distinct molecular weights (MW) with nominal MWs of about >5 x 10(4) (T(1)) and approximately 7.6 x 10(3) (T(2)) and with varying relative abundance among samples. The T(1)-peak intensity correlated strongly with [UDON] (r(2)=0.516, p<0.001), while T(2)-peak did not, which suggested that the T-peak is composed of a mixture of compounds with different chemical structures and ecological roles, namely proteinaceous materials and presumably phenolic moieties in humic-like substances. Natural source of the latter may include polyphenols leached from senescent plant materials, which are important precursors of humic substances. This idea is supported by the fact that polyphenols, such as gallic acid, an important constituent of hydrolysable tannins, and condensed tannins extracted from red mangrove (Rhizophora mangle) leaves exhibited the fluorescence peak in the close vicinity of the T-peak (260/346 and 275/313 nm, respectively). Based on this study the application of the T-peak as a proxy for [DON] in natural waters may have limitations in coastal zones with significant terrestrial DOM input.     

粮油食品中呕吐毒素危害及风险分析

该文分析呕吐毒素性质,在自然界和粮油食品中存在情况,及对人类和动物危害,并进行风险评估,同时提出预防呕吐毒素危害建议。     

Impact of durum wheat milling on deoxynivalenol distribution in the outcoming fractions

The milling behaviour of two naturally infected samples of durum wheat grain with contrasting levels of mycotoxins was studied. Although the two samples showed a similar milling behaviour, an increase of ～20% in deoxynivalenol (DON) levels was found in semolina from the sample containing the higher level of mycotoxin. However, even if the highest concentration of DON was found in fractions originating from the grain outer layers, the mycotoxin contamination in semolina and flours were not related to the amount of two compounds (ash or phytic acid) used to monitor these external tissues. The presence of the trichothecene-producing fungi in the inner-most semolina fraction was also shown using specific DNA primers and PCR amplification. Comparison of DON concentrations in the feed stock and corresponding output at each milling step or grinding of semolina fractions followed by sizing showed that concentration of mycotoxin occurs in the finest particles at the first processing steps. Therefore, DON contamination of milling fractions is not simply due to the presence of peripheral grain tissues.     

Organic nitrogen transformations in a 4-stage Bardenpho nitrogen removal plant and bioavailability/biodegradability of effluent DON

Nitrogen species, specifically, the fate and occurrence of organic nitrogen (ON) within a 4-stage Bardenpho process bioreactor producing low total nitrogen (TN) effluents were investigated in this study. The results showed release of ON in primary anoxic zone and no ON release in the first aerobic zone of the process. The research included investigation of biodegradability/bioavailability of wastewater-derived effluent dissolved ON (DON). The final-effluent DON utilization was evaluated by two different bioassay protocols in the presence and absence of nitrate. About 28–57% of the effluent DON was bioavailable/biodegradable. Bioavailable (to algae and bacteria) DON (ABDON) and biodegradable (to bacteria) DON (BDON) results did not show significant differences in terms of quantity, but DON utilization rates by ABDON (0.13 day⁻¹) protocol were higher than that of the BDON (0.04 day⁻¹) protocol in the nitrate-removal samples. As a result, ABDON requires a shorter time to exert the bioavailable fraction due to symbiotic relationship between algae and bacteria. In the nitrate-containing samples, it appears that nitrate competes with labile DON as a nitrogen source to microorganisms in both ABDON and BDON protocols. The first order decay rate of DON in the presence of nitrate was 0.11 day⁻¹ and 0.02 day⁻¹ for ABDON and BDON, respectively.     

运用免疫亲和柱和高效液相色谱(HPLC)检测啤酒大麦中的脱氧雪腐镰刀菌烯醇

采用免疫亲和柱净化、高效液相色谱定量等方法对啤酒大麦中的脱氧雪腐镰刀菌烯醇(DON)进行检测。向啤酒大麦中加入标准品,加标的范围在0.10～2.00μg/g,加标回收率为92.04%～97.29%,相对标准偏差是0.92%～2.67%。检出限是0.01μg/g。所测样品中DON的含量范围在0.0123～0.0926μg/g,其中江浙、云南和东北产区的啤酒大麦中DON含量较高。     

Occurrence and levels of mycotoxins and their metabolites in human breast milk associated to dietary habits and other factors: A systematic literature review, 1984–2015

BackgroundMany studies around the world reported the occurrence of many mycotoxins and their metabolites in human breast milk. However the contamination by aflatoxin M1 and ochratoxin A were the most investigated by several countries.Scope and approachTo scrutinize all papers reporting quantitative data on the prevalence and the levels of mycotoxins and their metabolites in breast milk, also the circumstances of exposure.A systematic literature search in Pubmed, Science direct and Google scholar databases were performed to identify relevant studies, published in English from 1984 through May 2015.Key findings and conclusion63 studies met the inclusion criteria and assessed the occurrence of 29 mycotoxins & their metabolites in breast milk, regarding 7194 subjects of 31 countries. The maternal dietary habits, the socio demographic status of the mother, the seasonal variations and the sensitivity of the analytical method were the factors related to the high concentrations of AFM1 and OTA in breast milk.Studies where contamination exceeds maximum limits and exhibit real risk of public health were highlighted.     

粮食中呕吐毒素的物理消减方法研究进展

呕吐毒素是广泛存在于粮食中的一种真菌毒素,其化学性质稳定,耐高温,对人类和动物的健康有比较严重的危害性。粮食中呕吐毒素的物理消减方法主要包括谷物加工法、吸附剂吸附法、射线辐照法和热处理法等方法。与化学脱毒法相比,物理脱毒法的成本低,处理过程中不会产生新的化学物质,且有助于减少粮食和饲料中现有的呕吐毒素。该文分析了粮食中呕吐毒素产生的原因、危害和污染现状,总结了粮食中呕吐毒素物理消减方法的研究进展,分析了各种消减方法的优缺点,并提出未来物理消减方法的研究方向和发展趋势,为进一步开发自动化、规模化、简便化和低成本高效率的物理消减方法提供参考。