芸苔属蔬菜硫代葡萄糖苷含量

对芸苔属中白菜类、芥菜类和甘蓝类蔬菜的硫代葡萄糖苷 (简称硫苷 )组成与含量进行了评价。结果表明 ,散叶甘蓝硫苷总含量最高 ,其次是包包青菜、包心芥菜、芥蓝 ,小白菜的含量最低。不同的品种硫苷的类型和含量不同。白菜类中 ,小白菜主要的硫苷为 3-丁烯基和 1 -甲氧基 - 3-吲哚基甲基硫苷 ,菜心中为 3-丁烯基和 2 -羟基 - 3-丁烯基硫苷 ,苔菜中为1 -甲氧基 - 3-吲哚基甲基和 4-戊烯基硫苷。在芥菜类中 ,发现了两种不同硫苷类型 ,烯丙基硫苷是包包青菜、包心芥菜主要的硫苷 ,约占总含量的 90 % ;而在小叶芥中 3-丁烯基为主要的硫苷 ,占总含量的大约 70 %。甘蓝类中羽衣甘蓝主要含有3-吲哚基甲基硫苷和 3-甲基硫氧丙基硫苷。 4-甲基硫氧丁基硫苷的含量以芥蓝中最高 ,此外 3-丁烯基硫苷的含量也比较高。在散叶甘蓝中 ,2 -羟基 - 3-丁烯基硫苷是主要的组成 ,约占总含量的 43% ,烯丙基硫苷和 3-吲哚甲基硫苷占总含量的2 0 %左右 ,芥蓝中萝卜硫素前体 4-甲基硫氧丁基硫苷的含量可达 1 2 4 .1 μmol/ 1 0 0 g FW,是很有抗癌价值的十字花科蔬菜。     

甘蓝不同部位及加工对硫代葡萄糖苷组分和含量的影响

采用高效液相色谱法对甘蓝内叶、外叶、漂烫及真空干燥后的硫苷含量进行了成分鉴定及组分分析.结果表明,甘蓝内叶与外叶的组分相同,通过HPLC-ESI-MS共鉴定出5种脂肪族硫苷(3-甲基硫氧丙基GS,2-羟基-3-丁烯基GS,2-丙烯基GS,3-丁烯基GS,4-戊烯基GS)和1种吲哚族硫苷(3-吲哚基甲基GS),甘蓝中主要硫苷成分为2-羟基-3-丁烯基GS,2-丙烯基GS,3-吲哚基甲基GS及3-甲基硫氧丙基GS,内叶和外叶中硫苷含量分别为1 972 μg/g干重和1 941 μg/g干重,漂烫和真空干燥后硫苷的保存率分别为87.7％和37.4％.     

热烫对4种芸薹属蔬菜硫代葡萄糖苷及其吲哚族降解产物的影响

研究了热烫对甘蓝、娃娃菜、小白菜和瓢儿菜4种芸薹属蔬菜硫苷及其吲哚族硫苷降解产物的影响。结果表明,4种蔬菜硫苷含量明显不同,鲜甘蓝中总硫苷含量最高(89.73μmol/g干重),鲜瓢儿菜总硫苷含量最低(34.94μmol/g干重)。新鲜蔬菜在90℃下分别用水热烫处理20、40、60 s后,各蔬菜的硫苷含量均显著降低,热烫60 s,总硫苷物质损失71%~73%。新鲜蔬菜总吲哚族硫苷降解产物含量相近,90℃热烫20~60 s能显著提高其吲哚族硫苷降解产物含量。结果表明,热烫60 s能使4种芸薹属蔬菜的吲哚族硫苷降解产物含量增加1~5倍,有利于提高其抗肿瘤、抑菌等生理活性,可作为蔬菜烹饪预处理的手段之一。     

番荔枝单体Bullatacin调节Th1/Th2平衡对小鼠H22肝癌的抑制作用研究

目的研究番荔枝单体Bullatacin对C57BL/6J小鼠接种H22肝癌细胞形成移植瘤的作用及其影响。方法将雌雄各半C57BL/6J小鼠分为空白对照组、模型组、Bullatacin干预组和顺铂对照组,每组10只,每只接种H22细胞数量1×106。Bullatacin浓度100μg·m L^-1,每次0.1 m L腹腔注射,每天1次,连续3天,14天后取材。结果 Bullatacin可抑制移植瘤的生长,其疗效优于顺铂组（P<0.05）。免疫组化结果显示Bullatacin可抑制移植瘤Ki67的表达。C57BL/6J小鼠空白对照组淋巴细胞表达白介素-4（IL-4）的阳性率为（17.3±0.35）%,而在形成移植瘤后为（24.2±0.32）%,Bullatacin干预后为（12.7±0.35）%,顺铂对照组为（11.2±0.33）%。C57BL/6J小鼠空白对照组淋巴细胞γ-干扰素（IFN-γ）的阳性率为（13.4±0.34）%,而在形成移植瘤后为（5.6±0.33）%,顺铂对照组为（6.2±0.35）%,Bullatacin干预后为（14.3±0.33）%。通过淋巴细胞分析表明,移植瘤使Th1/Th2漂移,而Bullatacin可使Th1/Th2向正常转化,顺铂则无此作用。C57BL/6J小鼠的血清IFN-γ含量为（132.2±6.7）pg·m L^-1,接种H22后为（98.9±6.8）pg·m L^-1,使用顺铂后为（77.5±7.0）pg·m L^-1,而在Bullatacin干预后达到（161.5±6.5）pg·m L^-1。C57BL/6J小鼠的血清IL-4为（6.20±1.0）pg·m L^-1,接种H22形成移植瘤后显著升高,达到（16.25±1.1）pg·m L^-1,顺铂干预后为（3.70±1.1）pg·m L^-1,使用Bullatacin干预后为（6.51±1.2）pg·m L^-1,空白组、模型组和Bullatacin干预之间的差异具有统计学意义（P<0.05）。结论番荔枝单体Bullatacin可以有效缩小H22肝癌细胞形成的移植瘤,促进Th1/Th2恢复至平衡状态。     

鲜切紫甘蓝中花青苷和硫代葡萄糖苷在贮藏过程中的变化

采用高效液相色谱和液相色谱-质谱联用技术,对紫甘蓝（Brassica oleracea L. ssp. capitata f. rubra）中花青苷、硫代葡萄糖苷（简称硫苷）成分和含量进行鉴定和分析,并对低温（8±1）℃条件下经鲜切处理的紫甘蓝中花青苷和硫苷在货架期内（7 d）的变化情况进行研究。结果表明：紫甘蓝中存在11 种不同矢车菊花青苷,矢车菊-3-阿魏酰-槐糖苷-5-葡萄糖苷作为紫甘蓝中最主要的花青苷,在贮藏过程中的损失量占总花青苷损失量的55.51%,其占总量比例也在贮藏7 d后由35.12%下降至30.60%;紫甘蓝中存在10 种硫苷（由6 种脂肪族硫苷、3 种吲哚族硫苷和1 种芳香族硫苷组成）,以4-戊烯基硫苷和3-丁烯基硫苷为主,贮藏7 d后,二者损失率均为7%左右,损失量相加却达总花青苷损失量的50.07%,而所占比例相加也由71.68%上升到74.33%。     

磷钾肥对云南旱作马铃薯产量和养分吸收的影响--测试文章

在云南省曲靖地区的低肥力和中高肥力试验地分别开展旱作马铃薯的田间小区试验,研究磷钾施用量对马铃薯生物量、养分利用、产量和经济效益的影响。结果表明：相同施肥量的条件下,中高肥力试验地的东山组马铃薯产量远高于低肥力的越州组,产量相差10 305.00～20 140.20 kg·hm^-2;越州组NP2K3(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 405 kg·hm^-2)处理产量产值最高,NP2K1(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 135 kg·hm^-2)处理净收益最高; 东山组NP2K2(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 270 kg·hm^-2)处理产量、产值及净收益均是最高; 两组试验的马铃薯干重变化趋势相似,NP2K2处理的干重积累量较多,无钾无磷处理干重积累少;马铃薯体内累积K最多,其次为N,最后为P, NPK养分吸收积累的高峰期在马铃薯块茎膨大期到淀粉积累期; 东山组的马铃薯PK利用效率明显高于越州组。NP1K2(N,150 kg·hm^-2; P₂O₅,45 kg·hm^-2; K₂O, 270 kg·hm^-2)处理的P肥利用率和P素农学效率较高,P肥利用率和P素农学效率都有随施P量增加而降低的趋势。NP2K1处理的K肥利用率和K素农学效率最高,K肥利用率和K素农学效率均有随施K量增加而降低的趋势。     

府谷县耕地糜子种植适宜性研究--测试文章

为了更合理地开发和利用当地有限的耕地资源,维护和提高耕地生产力,采用府谷县2011年“测土配方施肥”项目数据,基于GIS技术平台,综合利用地统计学、特尔斐法、综合评价法等方法,结合“3414”田间肥效试验结果,建立府谷县糜子种植适宜性评价体系。结果表明：对糜子种植而言,府谷县土壤有机质含量偏低（＜10 g·kg^-1）,碱解氮含量中等（25～40 mg·kg^-1）,有效磷含量偏低（5～10 mg·kg^-1）,速效钾含量中等（70～100 mg·kg^-1）。研究区耕地糜子种植适宜性水平分异大,高度适宜的耕地面积占总耕地面积的11.20%,适宜占28.99%,二者多沿河流阶地分布;勉强适宜占54.62%,遍布黄土丘陵区;不适宜占5.19%,呈点缀状分布于中部黄土丘陵区。增施碱解氮和有效磷,提高土壤有机质含量,保持土壤速效钾含量,同时注意改善土壤结构,提高土壤抗旱保肥和供肥能力,进一步提高糜子种植适宜性水平。     

秸秆还田下减量施氮对作物产量及养分吸收利用的影响--测试文章

秸秆还田条件下,采用多年田间定位试验研究了N肥减量施用对作物产量、养分吸收利用以及土壤表观N平衡的影响,旨在为关中小麦/玉米一年二熟轮作区合理施用N肥提供依据。结果表明：与常规施N处理(玉米季施氮187.5 kg·hm^-2,小麦季施氮150 kg·hm^-2)相比,2008—2011年三年中,15%减N、30%减N两个处理均未显著降低作物籽粒与秸秆产量;2010—2011年生长季中,15%减N处理降低了作物秸秆N、P、K周年总吸收量,增加了籽粒N、P、K周年总吸收量,其中籽粒P周年总吸收量增加达显著性水平;30%减N处理显著降低了籽粒N和秸秆N、K周年总吸收量,降幅分别为12.9%、41.9%、18.5%,在小麦收获后,30%减N处理的N素盈余量只有11.3 kg·hm^-2,有潜在缺N危险。综合考虑产量、养分吸收利用及土壤表观N平衡,在秸秆还田条件下,15%减N处理的施N量（即玉米季施氮159 kg·hm^-2,小麦季施氮127.5 kg·hm^-2）为本地区最佳N肥用量。     

气介式超声强化西兰花热风干燥过程中硫苷分解代谢途径相关物质的变化

为探究气介式超声对西兰花热风干燥过程中硫苷分解代谢的影响，本文研究了西兰花小花球在气介式超声联合热风干燥（20 kHz，60 ℃，125.2和180.1 W/dm2）过程中的干燥特性以及硫苷、萝卜硫素、抗坏血酸、Fe2+和酚酸含量以及黑芥子酶、体外抗氧化活性的变化规律。结果表明:相比于单独热风干燥，超声处理不仅可以加快干燥进程（125.2和180.1 W/dm2超声处理下干燥时间分别比单独热风干燥缩短11.1%和17.8%），同时，超声联合热风干燥过程中3-吲哚甲基硫苷含量增加且黑芥子酶活力增强。180.1 W/dm2气介式超声联合热风干燥终点样品中3-吲哚甲基硫苷、萝卜硫素含量和黑芥子酶活力分别比单独热风干燥终点的样品高出10.7%、26.0%和15.2%，Fe2+含量比单独热风干燥终点的样品低8.1%，表明超声处理减少了Fe2+对硫苷酶促降解的干扰，能够促进4-甲基硫氧丁基硫苷降解形成萝卜硫素，但超声处理对西兰花干燥过程中抗坏血酸含量、游离酚酸含量和体外抗氧化活性变化影响不明显。本研究表明气介式超声联合热风干燥既能加快西兰花干燥进程，又能促进4-甲基硫氧丁基硫苷的转化，并对生物活性成分具有一定的保护作用。     

粉葛愈伤组织不同极性提取物生物活性与功能成分分析

目的 为探究粉葛愈伤组织次生代谢产物的生物活性和功能成分。方法 采用系统溶剂法制备粉葛愈伤组织石油醚提取物(petroleum ether extract,PE)、乙酸乙酯提取物(ethyl acetate extract,EE)、甲醇提取物(methanol extract,ME)和水提取物(water extract,WE)等4种不同极性次生代谢产物,利用8株细菌、2个自由体系和1个细胞系测试四种提取物的抗菌、抗氧化和细胞毒活性,分析4种提取物中总黄酮、总酚、总多糖等主要功能成分含量与生物活性的相关性,并运用高效液相色谱法(high performance liquid chromatography,HPLC)检测其单体功能成分。结果 四种提取物的生物活性显著差异,其中EE对粪肠球菌、金黄色葡萄球菌、藤黄微球菌等革兰氏阳性菌作用突出,其最小抑菌浓度(minimum inhibitory concentration,MIC)为0.195~0.391 mg.mL_-1^,EE对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS)自由基清除能力均最佳,其半抑制浓度(half maximal inhibitory concentration,IC₅₀)分别为0.2795和0.0640 mg.mL_-1^,EE对人肺癌细胞A549(human lung cancer cell)的抑制能力较佳,其半最大效应浓度(concentration for 50% of maximal effect,EC₅₀)为260.9 μg.mL_-1^{。总黄酮和总酚在}EE中含量均最高,分别为(273.89±7.48)μg.mg_-1^和(261.00±14.94)μg.mg_-1^,总多糖在WE中含量最高,达到(402.25±13.49)μg.mg_-1^,相关性分析显示,总黄酮为重要的抗菌和抗氧化活性成分。异黄酮单体功能成分在四种提取物中组成和含量差异均较大,且主要集中在EE和ME,其中EE以大豆苷(30.3428±1.4251)μg.mg_-1^{和大豆苷元}(45.7235±2.0230)μg.mg_-1^为主,ME以大豆苷(60.0125±3.9250)μg.mg_-1^{和染料木苷}(20.5655±1.3025)μg.mg_-1^为主。结论 粉葛愈伤组织次生代谢产物具有较强的抗菌、抗氧化活性以及微弱的细胞毒活性,主要含有大豆苷、染料木苷和大豆苷元等功能成分,该结果为粉葛愈伤组织次生代谢产物在食品与制药领域的开发利用提供了一定的参考。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.