小麦中呕吐毒素的分布规律及加工影响

采用自然污染不同程度呕吐毒素的小麦为材料,通过检测制粉工艺过程中不同产物如麸皮、细麸、皮粉、心粉中呕吐毒素含量,探索小麦不同部位呕吐毒素的含量分布及制粉工艺中去除DON的效果。结果表明:呕吐毒素在小麦中的污染程度从外到内逐步递减;经过小麦制粉加工工艺后,存留在面粉中的DON浓度仅为原来小麦中DON浓度的49.17%～77.68%,而粗麸及细麸中DON浓度为原来小麦中DON浓度的132.00%～185.96%。另外,小麦中呕吐毒素的含量跟赤霉病粒的含量不存在完全的一一对应的线性关系,赤霉病粒含量的多少不能完全反应小麦中呕吐毒素的含量。     

实验制粉去除小麦中脱氧雪腐镰刀菌烯醇(DON)的研究

采用自然污染脱氧雪腐镰刀菌烯醇(DON)毒素不同程度的9种小麦为材料,通过检测其经实验制粉工艺得到麸皮、细麸、不同出粉点面粉包括最后统粉的DON含量,探索小麦实验制粉工艺去除DON的效果。结果表明:经过小麦实验制粉工艺后,能够重新分配小麦中的DON毒素,存留在面粉中的DON总量仅为原来小麦的31.03%～50.39%,并主要分布在小麦的表皮中,在小麦胚乳中也呈从内到外逐渐升高。制得面粉统粉中DON含量减少23.67%～58.97%,心磨粉最高能减少70.51%。小麦籽粒DON含量与制得面粉中DON含量之间呈幂函数回归关系,回归方程为y=0.498x1.206(R2=0.991),随着DON污染程度越低,DON含量减少率越大。以上实验证明,小麦制粉工艺是一种有效的去除小麦中DON毒素的方法。     

商业小麦麸皮的营养与安全品质研究

收集不同地区,4个厂家的12种商业麦麸(粗麸、细麸)进行理化及安全特性的分析。结果表明不同麸皮间存在较大差异,同类小麦得到的粗麸与细麸间也存在差异。其中粗淀粉含量差异性(CV=23%)最大,粗蛋白和植酸含量差异性(CV=8%)最小。小麦麸皮氨基酸组成中谷氨酸平均含量最高为3.11%,半胱氨酸平均含量最低为0.03%。安全指标测定中呕吐毒素有4个样品超标,赭曲霉毒素有2个样品超标,其他毒素均未超标。重金属测定中仅镉含量有1个样品超标,其余均在限定范围内。细麸相比粗麸中灰分、总膳食纤维和呕吐毒素的含量更高。而粗脂肪、粗蛋白、粗淀粉、植酸和玉米赤霉烯酮的含量是细麸中的含量高于粗麸中的含量。这种规律与粗麸、细麸的主要组成是密切相关的。     

真菌毒素在赤霉病小麦研磨及其湿法加工中的分布研究

小麦赤霉病不仅会导致粮食减产,更会引起多种真菌毒素的高污染风险。将染病小麦进行实验室制粉并湿法分离统粉中的粗淀粉、谷朊粉,采用酶联免疫吸附测定法(Enzyme-Linked Immuno Sorbent Assay,ELISA)测定各系统的呕吐毒素(Deoxynivalenol,DON)、黄曲霉毒素B1(Aflatoxin B1,AFB1)、玉米赤霉烯酮(Zearalenone,ZEN)以及赭曲霉毒素A(Ochratoxin A,OTA)的含量,以探究赤霉病小麦在制粉及其湿法加工中四种常见真菌毒素的分布变化规律。结果显示:研磨制粉及湿法加工对真菌毒素的分布影响显著。制粉加工后,皮磨和心磨系统粉的DON、AFB1、ZEN和OTA含量比原粮显著降低,降低率分别为1.38~16.24%、20.47~71.77%及26.71~69.51%;湿法加工产物中,DON消减为相应统粉的4.88~12.11%,AFB1与OTA浓缩富集,富集率分别可达统粉的2.55、3.65倍,粗淀粉中ZEN消减为统粉的12.70~15.83%,谷朊粉则富集为统粉的4.11倍。研究表明,在工业生产中,可根据赤霉病小麦的感染类型及程度,适当选用研磨或湿法加工等合适的方法加工处理。     

氧脂素对赭曲霉孢子产生、赭曲霉毒素A合成及粮食受侵染程度的影响

为明确氧脂素羟基十八碳二烯酸（hydroxyoctadecaenoic acid,HODE）对不同密度赭曲霉的孢子产生和赭曲霉毒素A（ochratoxin A,OTA）合成的作用,测定不同密度赭曲霉培养过程中9S-HODE、13S-HODE和OTA的产量,添加9S-HODE和13S-HODE后孢子和OTA产量,最后测定不同密度赭曲霉对粮食的侵染程度。结果显示,低接种密度的赭曲霉9S-HODE/13S-HODE比值及OTA产量更高;添加9S-HODE抑制赭曲霉孢子形成、促进OTA合成,13S-HODE作用相反;孢子接种密度为103?个/mL和106?个/mL的赭曲霉侵染花生、大豆、玉米及小麦后,发芽率分别降低29%、21%、17%、14%和35%、29%、20%、22%。这表明群体密度影响赭曲霉9S-HODE、13S-HODE和OTA产量,9S-HODE和13S-HODE可能是赭曲霉群体感应信号分子,二者在调节赭曲霉孢子产生和OTA合成上作用相反,高群体密度赭曲霉对粮食的侵染能力更强,脂肪及蛋白含量高的粮食可能更易被赭曲霉侵染。     

雾化着水机在制粉工艺中的应用

现代制粉工艺中大都设计有磨前喷雾着水,它可使入磨小麦皮层水分显著增加,经短暂润麦后再入磨研磨。小麦皮层水分增加,韧性增强,抗剪切能力提高,从而减少研磨过程中麸皮的破碎,减少面粉中麸星含量,提高面粉质量。根据经验,使用磨前喷     

veA基因影响黑曲霉生长及赭曲霉毒素合成

为探究全局调控因子veA基因对黑曲霉生长发育及赭曲霉毒素合成的影响,采用农杆菌介导的同源重组方法,构建过表达veA基因的黑曲霉菌株,比较出发菌株（黑曲霉CICC 41702）与veA过表达菌株（OE：：veA）在形态发展和赭曲霉毒素合成方面的差异。结果表明：OE：：veA菌株中veA基因的表达量与出发菌株相比提高了299%。相比于出发菌株,OE：：veA突变株的生长速度与出发菌株基本一致,但菌丝枝节较少且枝节较短,菌丝整体疏散,有更多的分生孢子头;赭曲霉毒素 β（ochratoxin β,OTβ）、赭曲霉毒素 α（ochratoxin α,OTα）、赭曲霉毒素 B（ochratoxin B,OTB）以及赭曲霉毒素A（ochratoxin A,OTA）含量都有大幅度降低。在培养的5、6 d和7 d中,出发菌株的OTA含量呈上升趋势,OE：：veA突变株基本保持不变,与出发菌株相比,OE：：veA菌株OTA的含量相对减少46%、63.33%、和75.81%。     

高效液相色谱法测定猪肾脏中赭曲霉毒素A

建立高效液相色谱法测定猪肾脏中赭曲霉毒素A(OTA)的含量。采用免疫亲和柱净化,Zorbax SB-C18柱(4.6 mm×250 mm,5μm)为色谱柱,乙腈-2%乙酸为流动相,激发波长(λem)为332 nm,发射波长(λex)为460 nm。结果显示,赭曲霉毒素A在0.1 ng/mL~10 ng/mL范围内线性关系良好(R~2=0.999 9),平均加样回收率为77.3%~84.4%,平均相对标准偏差(RSD)为0.8%~1.3%。该方法简便、准确性好、灵敏度高,可用于猪肾脏中赭曲霉毒素含量的测定。     

葡萄赭曲霉毒素污染及其产毒素菌株的筛选方法研究进展

赭曲霉毒素A(ochratoxin,OTA)是由曲霉属和青霉属等真菌产生的一类真菌毒素,其毒性很强,分布广泛,对人类和动植物的健康有着巨大的影响。葡萄及其制品是食品中OTA的主要来源之一,从病害的葡萄表面筛选分离产生赭曲霉毒素的菌株是最常用的研究产毒素菌株的方法。由于产毒素菌株主要分布在葡萄果实的表面,葡萄组织受损后会极大提高赭曲霉素的污染程度,研究产毒菌株分布及产毒素能力对控制赭曲霉素污染及寻找一种有效地生物防治方法提供参考。本文综述了葡萄赭曲霉毒素的污染情况及其产毒素菌株的筛选方法,为控制葡萄及其产品中的OTA污染提供依据。     

高效液相色谱-串联质谱法检测茶叶中的 赭曲霉毒素A

目的建立高效液相色谱-串联质谱联用技术检测茶叶中赭曲霉毒素A(OTA)的方法。方法用甲醇-2%Na HCO3溶液(60:40,V:V)提取样品中的赭曲霉毒素A,采用免疫亲和柱对茶叶中的赭曲霉毒素A净化,使用甲醇-5 mmol/L乙酸铵(含0.1%乙酸)为流动相,检测赭曲霉毒素A,采用正离子模式。结果本方法中赭曲霉毒素A在0.5~10 ng/m L质量浓度范围内具有良好的线性关系(r=0.996),回收率在83.6%~92.5%之间,相对标准偏差在6.5%~9.1%之间,检出限为0.1μg/kg。结论该方法准确性好、灵敏度高,适用于茶叶样品的检测。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.