没食子酸和芦丁对鱼皮明胶凝胶的溶胀性及水的状态的影响

研究没食子酸和芦丁对鱼皮凝胶的溶胀性及水的状态的影响。结果表明,没食子酸和芦丁均可使凝胶的平衡溶胀率降低,以芦丁的影响较显著。在凝胶溶胀初期,未交联凝胶和没食子酸添加量20mg/g凝胶以及芦丁添加量为6和8mg/g凝胶均表现非Fick扩散过程,而30mg/g没食子酸交联的凝胶表现Fick扩散过程。同时发现,无论是未交联凝胶还是多酚交联凝胶,在溶胀过程中均是凝胶高分子链的松弛过程为速控步骤。通过差示扫描量热法(DSC)对多酚交联凝胶中水的状态分析发现,没食子酸和芦丁对凝胶的平衡水分含量没有明显影响,但可改变凝胶中可冻结水和非冻结结合水的分布。20和30mg/g的没食子酸使凝胶中非冻结结合水含量降低,而6和8mg/g的芦丁却使凝胶中非冻结结合水含量升高。     

亚麻籽双液相萃取中醇相组分体外抗氧化活性研究

采用体外实验方法对亚麻籽双液相萃取中乙醇相的氯仿、正丁醇和水三种提取物进行抗氧化活性研究。结果表明:乙醇相三个萃取组分中,以正丁醇提取物抗亚油酸氧化能力最强,比BHT略弱。氯仿提取物次之,强于VC,水提取物最弱。在对[DPPH·]自由基的清除能力上,正丁醇提取物最强,IC50为3.1μg/ml,比芦丁(IC50=3.38μg/ml)强。水提取物略弱于BHT,氯仿提取物最弱;正丁醇提取物对[·OH]自由基的清除能力最强,IC50为18.15μg/ml,比芦丁(IC50=7.96μg/ml)弱。氯仿提取物次之,水提取物最弱;正丁醇提取物螯合Fe2+的能力最强,氯仿提取物次之,而水提取物最弱。     

苦荞发芽期不同部位的活性成分含量变化

苦荞发芽后,将其分为芽及去除芽后的籽粒两部分,在发芽期间,对芽和籽粒中的总黄酮、芦丁、槲皮素及D-CI含量变化进行研究。发芽第二天开始,随着发芽时间延长,芽粉中总黄酮、芦丁、D-CI含量呈下降趋势,槲皮素含量缓慢上升;发芽第二天,芽粉中D-CI含量高达18.38 mg/g,未萌动的苦荞全粉中D-CI含量为0.32 mg/g。随发芽时间延长,全粉中总黄酮、芦丁含量呈先上升后下降趋势,在发芽萌动第七天总黄酮含量达到最大值,为27.92 mg/g,第六天芦丁含量达到最大,为23.13 mg/g;槲皮素含量变化呈上升趋势,在发芽中后期含量上升迅速,发芽第八天其含量为6.85 mg/g;D-CI含量变化呈缓慢上升趋势,第一天其含量为1.07 mg/g,第六天其含量为1.51 mg/g。芽粉中总黄酮、芦丁、D-CI在发芽初期含量较高;全粉中D-CI的合成也主要发生在发芽初期,芦丁、槲皮素的合成主要在发芽中后期。     

热处理对苦荞麦粉总抗氧化能力的影响

采用分光光度计法和抗氧化能量指数法对来自重庆市城口县的苦荞麦粉中总黄酮含量和抗氧化能力进行了分析。样品加热(100℃,20min,样品:水=1:2,w/v)前后,总黄酮含量为83.52mg芦丁当量/100g干重和67.38mg芦丁当量/100g干重,ORAC值为76.45μmol TE/g干重和63.93μmol TE╱g干重,损失分别达到19.32％、16.38％,呈显著差异(P<0.05)。但热处理前后的苦荞麦粉都表现出良好的抗氧化性。     

红枣芦丁提取的最佳工艺研究

目的研究提取红枣中芦丁的最佳工艺。方法以红枣为原料,以乙醇为有机溶剂提取目标产物芦丁。在单因素试验的基础上,采用响应面法优化红枣中芦丁的提取工艺,建立该工艺的二次多项数学模型,研究乙醇体积分数、浸取温度、料液比、p H值4个因素及其交互作用对提取工艺的影响。结果最佳工艺条件为:乙醇体积分数74%,浸取温度72℃,料液比43 m L/g,p H值8,芦丁理论提取率达7.58 mg/g。结论在此工艺条件下,进行的3次平行实验验证,得到芦丁提取率平均值约为7.56 mg/g,符合误差要求,为开发和利用红枣中的芦丁提供了依据。     

萌发荞麦中芦丁和槲皮素含量变化的研究

研究分析荞麦萌发过程中芦丁和槲皮素含量的变化趋势,为荞麦萌动食品的开发提供了理论参考。以发芽时间为试验因素,采用反相液相色谱法对荞麦萌发前后的芦丁和槲皮素进行测定比较。结果表明(1)萌发有助于提高苦荞中芦丁和槲皮素的含量,有助于提高甜荞中芦丁的含量。苦荞萌发7 d后芦丁含量为19.33 mg/g远高于甜荞的0.66 mg/g。(2)苦荞萌发过程中芦丁含量呈先上升后下降再上升的趋势,萌发7 d后芦丁含量提高了66.64%。甜荞萌发7 d后,芦丁含量提高了75.13%。苦荞萌发7 d,槲皮素含量整体呈上升趋势,由8.93 mg/g上升至11.90 mg/g。甜荞萌发过程中未检测出槲皮素。荞麦萌动后提高了黄酮类成分,苦荞中的芦丁含量萌发前后均高于甜荞,选择苦荞作为荞麦萌动食品原料具有更好的营养价值。     

超声提取日本楤木叶片芦丁工艺优化

利用响应面曲线法优化超声提取日本楤木叶片中芦丁的工艺条件。在单因素实验的基础上,采用中心组合设计响应面实验,研究了乙醇浓度、提取时间及液料比对日本楤木叶中芦丁提取量的影响,并建立了二次回归方程,确定提取芦丁的最佳工艺组合条件:乙醇浓度为76%,超声时间为54min,液料比为57∶1m L/g;该条件下日本楤木叶片中芦丁提取含量理论值为2.222mg/g,实测值为2.187mg/g。     

HPLC法测定菊苣中芦丁、槲皮素和山柰酚含量

建立HPLC法同时测定维药菊苣茎、根、种子总黄酮提取液中芦丁、槲皮素和山柰酚含量的方法。用安捷伦HC-C_(18)柱(250 mm×4.6 mm, 5μm)色谱柱,流动相为0.1%乙腈(A)-磷酸(B)(50︰50, V/V),流速0.8 mL/min,检测波长365 nm,柱温30℃。结果表明,芦丁、槲皮素和山柰酚分别在2.0～20μg/mL (r~2=0.999 9), 0.5～40μg/m L (r~2=0.999 8)和0.5～60μg/m L (r~2=0.999 1)浓度范围内呈现良好线性关系,加标回收率(n=3)分别为97.7%(RSD=1.89%), 97.3%(RSD=1.01%)和102.6%(RSD=0.33%)。菊苣茎中芦丁含量为116.3×10~3μg/kg,槲皮素为122.4×10~3μg/kg,山柰酚为32.7×10~3μg/kg;菊苣根中存在芦丁,含量为82.0×10~3μg/kg;菊苣子中存在芦丁和槲皮素,芦丁含量为85.0×10~3μg/kg,槲皮素为45.3×10~3μg/kg。该方法简便、快速、有效、灵敏、准确,具有良好回收率,可作为该植物的定量分析方法,试验结果可为以后菊苣资源的开发利用提供依据。     

反相高效液相色谱法测定苦荞中的芦丁和槲皮素

目的:建立一种苦荞黄酮中芦丁和槲皮素含量的测定方法。方法:分别以芦丁和槲皮素为标品,采用KromasilC18反相柱(4.6mm×300mm,5μm),分别测定水解和未水解苦荞黄酮样品中芦丁和槲皮素的含量。结果:在流动相为0.4%磷酸-甲醇(体积比为40∶60)、检验波长358nm、进样速度1.0mL/min、柱温20℃条件下,测定的芦丁含量的线性范围为0.025～0.125g/L(r=0.9993),槲皮素含量的线性范围为0.008～0.256g/L(r=0.9995)。槲皮素的加样回收率99.9%,变异系数为1.50%(x,n=5);芦丁的加样回收率98.5%,变异系数为1.16%(x,n=5)。水解样中槲皮素含量为(194.7±4.22)mg/g,未水解样中槲皮素含量为(8.96±0.26)mg/g,芦丁含量为(83.84±3.29)mg/g,变异系数(x,n=3)分别为:2.17%、2.90%和3.92%。结论:该方法简便、快速、准确,可用于苦荞黄酮中芦丁和槲皮素的含量测定。     

龙眼壳总黄酮的HPLC图谱分析

采用HPLC法以芦丁标准品为对照品,对经超声-微波协同萃取,并且经过AB-8大孔径树脂柱层析纯化的龙眼壳总黄酮进行定性分析。色谱柱条件为:C18柱,流动相为甲醇-水(25∶75),波长254 nm,流速0.5 m L/min,柱温为室温,进样量为2 u L的条件下进行检测。结论:龙眼壳样品中总黄酮含量达23.43 mg/g,龙眼壳总黄酮的主要成分为芦丁,在龙眼壳总黄酮初步纯化样品中芦丁含量达到63.95%。     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press