超声波处理对脱氧雪腐镰刀菌烯醇（DON）的降解效果研究

为了降低小麦中脱氧雪腐镰刀菌烯醇的含量,本文采用超声波处理促进其降解,考察了超声时间、超声振幅和脉冲占空比分别对DON纯品和赤霉病小麦籽粒中DON的降解效果。结果表明:延长超声时间、增大超声振幅、升高脉冲占空比都会在一定程度上促进纯品DON溶液和赤霉病小麦籽粒中DON的降解。综合考虑其经济效益,当超声时间为18 min、振幅为50%、脉冲占空比为100%(连续超声)时,纯品DON降解率最高(32.25%)。当超声时间为15 min、振幅为60%、连续超声时,赤霉病小麦籽粒中DON降解率高达37.59%,表明超声波处理对纯品DON和赤霉病小麦籽粒均有较好的降解效果。     

臭氧水协同超声波处理对小麦中DON降解效果的研究

为了研究臭氧水协同超声波处理对赤霉病小麦中DON降解效果的影响,采用不同协同方式对赤霉病小麦进行处理,并筛选出臭氧水和超声波协同的最佳方式。随后在最佳联合方式下进行单因素和正交实验来探讨臭氧水浓度、超声振幅和处理时间对赤霉病小麦籽粒中DON降解效果的影响。结果表明:臭氧水和超声波最佳联合处理方式为T5,即先超声波处理5 min再臭氧水处理5 min,此时赤霉病小麦中DON降解率最高(46.99%)。经单因素和正交实验得出,在此联合方式下臭氧水浓度为58.32 mg/L,超声振幅为60%,处理时间比为9:1时赤霉病小麦中DON降解率最高(51.02%)。     

60Co-γ辐照对赤霉病小麦中DON的降解效果

采用60Co-γ射线辐照技术处理赤霉病小麦,结果表明:此技术可以降解赤霉病小麦中一定量的DON,降解率随辐照剂量的增加而逐渐升高。当辐照达到安全剂量10 k Gy时,赤霉病小麦籽粒中DON的降解率超过20%,若不结合其他小麦加工工艺,该技术可将DON含量低于1.25 mg/kg的赤霉病小麦降低到安全范围之内(DON含量≤1 mg/kg);小麦的物理形态、籽粒含水量及赤霉病感染程度对DON的辐照降解无显著影响(P0.05);此外,赤霉病麦粒经水浸泡后再辐照可以在很大程度上促进DON的降解,在安全剂量10 k Gy时降解率最高可达到55.76%。     

过热蒸汽处理对赤霉病小麦麸皮中脱氧雪腐镰刀菌烯醇降解效果研究

为提高赤霉病小麦麸皮利用率,使用过热蒸汽技术对赤霉病小麦麸皮进行处理。研究过热蒸汽温度、处理时间、蒸汽流速、麸皮水分含量4个因素对过热蒸汽降解麸皮中脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)的影响。结果表明,过热蒸汽处理可以显著降低赤霉病小麦麸皮中的DON含量,蒸汽温度240℃、处理时间10 min、蒸汽流速3 m/s、麸皮水分含量10%时,DON降解率达到最高值91.12%;在一定范围内提高蒸汽温度、延长处理时间、增大蒸汽流速均可以显著提高DON降解率(P<0.05),而水分含量升高则会显著降低降解率。     

清理和制粉工艺对去除污染小麦中DON效果及其小麦粉品质的影响

通过检测小麦清理工艺中各步骤的小麦和6种污染程度不同的小麦实验制粉后各粉路的DON含量,研究清理和制粉对小麦中DON的去除效果;通过检测污染前后小麦籽粒及其小麦粉的品质指标的变化,研究赤霉病对小麦及小麦粉食用和加工品质的影响。结果表明:清理和制粉均对DON有很好的去除效果,赤霉病感染小麦的加工和食用品质均下降,并随着污染程度的加深,品质越来越差。经过清理后,小麦中的DON含量由初始的1.56mg/kg下降到1.18mg/kg,DON去除率达24.36%,其中擦皮除菌机和色选机的清理效果最佳。6种污染程度不同的小麦实验制粉后,DON均有不同程度的去除,最高可达46.96%,轻度污染的小麦制粉后可达到国家产品安全标准要求。小麦中DON主要集中在小麦皮层部分,从外到内依次降低,小麦中心胚乳的DON含量最低;赤霉病对小麦及小麦粉的品质有较大影响,使小麦籽粒内部结构疏松,小麦粉烘焙品质和流变学特性也逐渐下降。     

臭氧和紫外降解面粉中的DON及对面粉品质的影响

为降低面粉DON含量,用臭氧及紫外线处理受污染的面粉,研究处理条件对降解效果的影响,对比处理前后面粉的蛋白含量、湿面筋含量和白度值并通过MTT法评价降解产物安全性。研究表明,在臭氧浓度45.00 mg/L,水分含量为16.00%的条件下处理DON污染面粉60 min,初始DON含量为2.35、2.84、4.09和4.95 mg/kg的面粉DON降解率分别为46.59%、40.71%、38.96%和35.40%;在紫外照射强度1200μW/cm2,水分含量12.00%的条件下处理DON污染面粉60 min,相同初始含量的DON降解率为39.89%、40.32%、36.68%和30.32%。两种处理后面粉蛋白质含量、湿面筋含量和白度等理化指标均无显著变化(p0.05)。MTT实验表明:DON对LO2有很强的细胞毒性,给药48h后细胞活性降低62.02%,相同DON浓度的紫外降解产物使细胞活性降低17.50%,臭氧降解产物则使细胞活性仅下降2%(p0.05)。本研究使用的方法可在短时间内有效降低面粉中DON含量,对面粉品质无显著影响,两种方法的降解产物对LO2细胞毒性均显著下降(p0.01)。     

赤霉病对小麦品质影响的研究

选取2012年江苏产硬质白小麦,制备不同赤霉病含量的小麦样品,探讨不同赤霉病含量对小麦籽粒品质、小麦粉品质影响程度,以及由小麦赤霉病病原菌分泌产生的脱氧雪腐镰刀菌烯醇(DON毒素)在小麦籽粒中积累分布情况。实验结果表明,随着小麦样品中赤霉病麦含量的升高,涉及小麦籽粒品质、小麦粉品质的主要指标明显下降;同时DON毒素在小麦籽粒中积累分布,皮层中含量明显高于胚乳(小麦粉)中的含量。     

二氧化氯对玉米乙醇发酵糟液中脱氧雪腐镰刀菌烯醇的降解

脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)是造成粮食污染的主要原因之一。采用高效液相色谱-质谱联用(HPLC-MS)对DON含量进行检测分析,通过液体浸泡法,探究了ClO_2对DON纯品以及玉米乙醇发酵糟液中DON的降解效果。结果显示:DON降解率随ClO_2溶液浓度的增大以及处理时间的延长而提高,且pH值对DON降解有影响。当pH值为4. 5～5. 5时,600 mg/L ClO_2溶液对DON纯品处理12 h,降解率为28. 23%,并产生了2种降解产物;该方法同样适用于玉米乙醇发酵糟液中DON降解,600 mg/L的ClO_2溶液对玉米发酵糟液处理12 h,降解率达40. 70%,降解效果较好,对处理乙醇发酵工艺中的DON或其他真菌毒素具有一定的指导意义,为大规模生产中对DON的去除提供了新的思路。     

不同加工方法对小麦粉中呕吐毒素的影响

通过比较使用不同加工方法对小麦籽粒不同部位呕吐毒素（DON）含量的影响，得出：1、皮粉、芯粉中DON的含量低于全麦粉中DON的含量，DON主要分布于小麦的表皮附近。2、小麦制粉前进行筛杂或清洗对降低DON的效果不同。筛杂对降低皮粉、芯粉中DON的效果更好，清洗对降低粗麸、细麸中的DON效果更好。3、使用不同加工方法产生的小麦粉或麦麸中DON含量几乎相同。4、当全麦粉的DON含量低于1.56 mg/kg时，通过筛杂、清洗、磨粉后芯粉的DON含量可能会低于1 mg/kg的规定值。     

小麦中呕吐毒素的影响因素和污染特性分析

以小麦为研究对象,分析影响呕吐毒素,即脱氧雪腐镰刀菌烯醇（deoxynivalenol,DON）含量的相关因素,研究小麦不同粒型及籽粒不同部位DON的污染特性、分布差异。结果表明,小麦籽粒染病、破损,籽粒粒径及虫蛀类型对DON污染均有影响,DON含量与不完善粒含量呈显著的弱正相关,与赤霉病粒含量呈显著的强正相关。相同品种的小麦样品,小麦不同粒型和籽粒不同部位,DON含量存在很大差异,其中赤霉病粒显著高于未染病粒,破损粒显著高于完整粒,小颗粒显著高于大颗粒,籽粒胚部显著高于胚乳,粒面DON含量占35.2%～52.1%。胚乳结构越靠近外层,DON污染越严重,越靠近籽粒中心,DON污染越轻,制粉后外层麸皮DON含量较高,而可食用的小麦粉含量较低。小麦通过分级、分选、水洗和制粉加工可有效降低DON的污染。     

臭氧降解污染小麦中呕吐毒素的效果及降解产物推测

利用臭氧降解小麦中的呕吐毒素,通过超高效液相色谱-串联四极杆飞行时间质谱（ultra performance liquidchromatography quadrupole time-of-flight mass spectrometry,UPLC Q-TOF MS）测定了纯水体系中呕吐毒素的臭氧降解产物。结果表明：全麦粉中的呕吐毒素降解率显著高于小麦籽粒。当小麦水分含量为20.10%,臭氧质量浓度为100 mg/L,处理60 min后,呕吐毒素含量由3.89 mg/kg 降到了0.83 mg/kg。建立的一级动力学方程显示臭氧反应速率为k100 mg/L＞k75 mg/L＞k50 mg/L＞k25 mg/L。根据UPLC Q-TOF MS得到离子碎片信息提出了可能的离子碎片生成途径并推测了臭氧降解产物结构,5 种主要产物的m/z分别为344.948 1、329.205 0、311.191 8、311.190 7和346.240 4。     

纳豆芽孢杆菌Bacillus natto 16-1对小麦粉中呕吐毒素的脱毒机制

采用酶联免疫吸附法(ELISA)及高效液相色谱—质谱(HPLC-mass spectrometry,HPLC-MS)检测纳豆芽孢杆菌Bacillus natto 16-1各细胞成分对小麦粉中呕吐毒素(deoxynivalenol,DON)的清除效果及降解产物,探讨纳豆芽孢杆菌清除呕吐毒素的效果及降解机制。结果显示,培养5h后不同浓度的菌悬液、发酵上清液、全菌裂解液、粗提酶液以及细胞壁悬浮液,对DON清除率均在53%以上,其中不同浓度的菌悬液处理间存在显著差异,高浓度细胞壁悬浮液处理对DON清除率高达62.85%;培养10h后不同菌体成分对DON的清除率在57%以上,其中不同浓度发酵上清液、菌体裂解液以及细胞壁悬浮液处理间存在显著差异。除细胞壁处理组外,其他各组均可将DON降解为分子质量较小的物质。结果表明,纳豆芽孢杆菌Bacillus natto 16-1各细胞成分对DON均有清除作用,且这种作用在一定程度与细胞成分的浓度及作用时间有关;各细胞成分对DON的清除机制主要是生物降解作用,细胞壁可能是通过生物吸附作用来清除DON。     

Determination of Deoxynivalenol in Wheat Bran and Whole-Wheat Flour by Fluorescence Polarization Immunoassay

A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in wheat bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds present in raw wheat bran extracts. In particular, matrix effect was removed by adding activated charcoal to the wheat bran extract (3.5 mg/mL) and mixing for 3 min of incubation time prior to the FP immunoassay analysis. No preliminary treatment was necessary for whole-wheat flour. Average recoveries from samples spiked with DON at levels of 500, 1,000, and 1,500 μg/kg were 95 % for wheat bran and 94 % for whole-wheat flour, with relative standard deviation generally lower than 13 %. Limits of quantification of the optimized FP immunoassay were 120 μg/kg for both matrices. The overall time of analysis was lower than 15 min for wheat bran and 10 min for whole-wheat flour. Good correlations (r?>?0.971) were observed between DON contents obtained by both FP immunoassay and high-performance liquid chromatography with immunoaffinity cleanup for 37 and 23 samples of naturally contaminated wheat bran and whole-wheat flour, respectively. These results show that the FP immunoassay is suitable for high-throughput screening as well as for quantitative determination of DON in wheat bran and whole-wheat flour.     

Chemical,Technological, and Sensory Properties of Wheat Grains (Triticum aestivum L) as Affected by Gaseous Ozonation

Gaseous ozonation, an emerging technology, is applied to microbiological decontamination and to the degradation of residues and contaminants in wheat grains. However, due to its high oxidizing capacity, ozone may cause undesirable effects on the quality of grains or in their derivatives. This study aimed to evaluate the influence of ozone gas on wheat grain quality when exposed to different levels of ozone concentration, exposure time, and grain mass, using a full 2³ factorial design. After the milling of ozonized grains, two fractions were evaluated: flour (A) and bran plus germ (B). In fraction A, the quality of the wheat flour was analyzed by both alveography and farinography. The flour extraction rate, falling number and gluten contents were also measured. The chemical and mineral profiles were determined in both fractions. A sensory evaluation, using the difference-from-control test, was applied to investigate the possible differences in aroma or in overall appearance of the flour obtained from the ozonized grains. The results showed that ozone concentration (60 mg/L) positively affected (p < 0.05) the toughness and the falling number of the flour. The other parameters of alveography, as well as farinography, gluten content, chemical composition, mineral, and sensory profiles were not affected (p > 0.05) by ozonation. This study demonstrated that gaseous ozonation, when applied under the conditions of 10 to 60 mg/L, from 2 to 5 h of exposure, grain mass from 2 to 5 kg, does not cause any negative impact on the wheat quality.     

处理方式对米根霉菌Rho18清除呕吐毒素的影响

通过酶联免疫吸附测定法(ELISA)及高效液相色谱—质谱联用仪(HPLC-MS)测定不同方式处理的米根霉菌Rho18对小麦粉中呕吐毒素(deoxynivalenol,DON)的清除效果,探讨米根霉菌对DON的清除能力。结果显示,米根霉菌Rho18对小麦粉中DON的清除率均随浓度增高及孵育时间的延长而提高,各高浓度处理组孵育10h后与其他处理组均存在显著差异,高浓度的细胞壁悬液与小麦粉孵育10h条件下对DON的清除效果最好(51.62%)。不同方式处理的米根霉菌Rho18与DON作用后产生3种相对分子质量在277,279,281左右的新物质。结果表明,不同方式处理的米根霉菌Rho18对DON均有一定清除作用,且作用效果与浓度和孵育时间相关,其清除机制主要为生物酶系作用。     

A survey on the occurrence of Fusarium mycotoxins in Bavarian cereals from the 1987 harvest

Summary Bavarian cereals and wheat flour from the 1987 harvest were analysed for nivalenol (NIV) and deoxynivalenol (DON) using high performance liquid chromatography (HPLC) and for T-2 toxin and zearalenone (ZEA) by enzyme-linked-immunosorbent as say (ELISA). The study included 190 field samples of wheat, barley, rye and oat with visibly damaged ears, 45 samples of wheat intended for feed production and two series of wheat flour (type 550) and whole wheat flour collected in October 1987 and June 1988. The field samples examined showed a high DON contamination of wheat (87%) with an average of 3.96 mg/kg and a maximum of 43.8 mg/kg. Mean levels between 0.33 mg/kg and 0.27 mg/kg DON could be detected in barley, rye and oat. Of the wheat samples, 58% contained ZEA with a maximum of 1.560 mg/kg. The highest levels of ZEA were detected in samples which also showed high concentrations of DON. The NIV and T-2 toxin levels were comparatively low. Thirty percent of the samples showed NIV concentrations between 0.04 mg/kg and 0.29 mg/kg and 38% contained between 0.005 and 0.60 mg/kg of T-2. In the wheat samples for feed production, only DON was detected with an average of 0.190 mg/kg and a maximum of 0.75 mg/kg. The highest DON levels (0.58 mg/kg) from October 1987 were found in the wheat flour samples which were lower than the highest DON concentration (3.24 mg/kg) detected in the samples collected during June 1988. This fact was probably due to a substantial amount of non-contaminated wheat from 1986. The toxin concentrations in the whole wheat flour were not higher than in the type 550 flour. The regional distribution of the mean DON concentrations showed the highest levels in Middle and Lower-Franconia.

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Vorkommen von Fusarium Mykotoxinen in bayerischem Getreide der Ernte 1987

Zusammenfassung Cerealien und Weizenmehle der bayerischen Ernte 1987 wurden mittels hochauflösender Flüssigchromatographie (HPLC) auf Nivalenol (NIV) und Deoxynivalenol (DON) Bowie mit Enzymimmunoassay auf T-2 Toxin und Zearalenon (ZEA) analysiert. Die Untersuchungen umfaßten 190 Feldproben von Weizen, Gerste, Roggen und Hafer, die alle optisch erkennbaren Fusarienbefall aufwiesen, 45 Futterweizenproben Bowie zwei Probenserien von Weizenmehlen der Type 550 und Vollkornweizenmehlen, die im October 1987 und im Juni 1988 gezogenwurden. — Die Untersuchungen der Feldproben ergaben eine hohe DON-Kontamination des Weizens (87%) mit einem durchschnittlichen Gehalt von 3,96 mg/kg und einem Maximalgehalt von 43,8 mg/kg. In Gerste, Roggen und Hafer konnten durchschnittlich zwischen 0,33 mg/kg und 0,27 mg/kg DON-nachgewiesen werden. 58% der Winterweizenproben wiesen Zearalenon mit einem Maximalgehalt von 1,56 mg/kg auf. Die höchsten ZEA-Werte wurden in Proben ermittelt, die gleichzeitig einen hohen DON-Gehalt aufwiesen. Die Konzentrationen von NIV und T-2 Toxin waren vergleichsweise niedrig. 30% der Proben hatten NIV-Gehalte zwischen 0,04 mg/kg und 0,29 mg/kg und 38% enthielten T-2 Toxin zwischen 0,005 mg/kg und 0,06 mg/kg. In den Futterweizenproben konnte DON als einziges Toxin mit einem Gehalt von durchschnittlich 0,19 mg/kg und maximal 0,75 mg/kg festgestellt werden. Die Weizenmehle, die im October 1987 gezogen wurden, wiesen maximal 0,58 mg/kg DON auf. Die Gehalte lagen damit medriger als die der Mehlproben vom Juni 1988, die maximal 3,24 mg/kg und durchschnittlich 0,26 mg/kg DON enthielten. Dieser Sachverhalt könnte auf Anteile von nicht kontaminiertem Weizen der Ernte 86 an den im October gezogenen Mehlproben zurückgeführt werden. Die Toxingehalte der Vollkornmehle waren nicht höher als die der Weizenmehle der Type 550. Die höchsten Durchschnittsgehalte von DON wurden in Mittel- und Unterfranken festgestellt.

     

Evaluation the quality characteristics of wheat flour and shelf-life of fresh noodles as affected by ozone treatment

In this study, the effects of ozone treatment on the microorganism mortality in wheat flour and shelf-life of fresh noodles were investigated, as well as the physicochemical properties of wheat flour and textural qualities of cooked noodles. Results showed that the total plate count (TPC) can be largely reduced in wheat flour exposed to ozone gas for 30 min and 60 min. Whiteness of flour and noodle sheet, dough stability, and peak viscosity of wheat starch were all increased by ozone treatment. Free cysteine content in wheat flour was shown to decrease significantly (P < 0.05) as the treatment time increased and remarkable protein aggregates were observed in both reduced and non-reduced SDS–PAGE patterns. In addition, ozone treated noodles were generally higher in firmness, springiness, and chewiness, while lower in adhesiveness. Microbial growth and darkening rate of fresh noodles made from ozone treated flour were delayed significantly.     

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil

ABSTRACT

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R² = 0.99). A negative matrix effect (?28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2–105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.