亮叶杨桐叶中酚类物质的抗氧化和抗HepG2细胞增殖作用

研究春秋两个季节亮叶杨桐叶中酚类物质体外抗氧化活性及对Hep G2细胞的抗增殖作用。采用福林酚法、硼氢化钠/四氯苯醌比色法、超氧自由基吸收能力(ORAC)、超氧自由基清除能力(PSC)、细胞抗氧化法(CAA)和亚甲基蓝染色法分析游离态/结合态多酚含量、游离态/结合态黄酮含量、游离态/结合态提取物胞外抗氧化能力、游离态提取物胞内抗氧化能力和游离态提取物对Hep G2细胞的抗增殖作用。秋季亮叶杨桐叶中游离态酚、游离态黄酮含量高,分别是142.69±0.58 mg GAE/g DW和112.98±0.37 CE/g DW;游离态提取物超氧自由基吸收能力强、超氧自由基清除能力强和细胞抗氧化能力强,分别是1723.08±109.27μmol TE/g DW、24.07±1.98μM VCE/g DW和900.84±2.68μmol QE/100 g;游离态提取物对Hep G2细胞的抗增殖作用强,EC50值为4.30 mg/m L。亮叶杨桐叶富含酚类物质,特别是秋季亮叶杨桐叶是一种新型的天然抗氧化剂的原料,可进一步开发。     

四种豆类中多酚、类黄酮含量及抗氧化活性研究

对豇豆、红小豆、绿豆和蚕豆4种豆类中游离态和结合态的多酚及类黄酮的含量进行测定,并比较了其体外抗氧化活性。数据表明,4种不同豆类的游离态多酚和结合态多酚含量范围分别为1.35～1.75 mg/g和8.63～10.11 mg/g;游离态类黄酮和结合态类黄酮含量范围分别为1.58～2.07 mg/g和3.92～5.08 mg/g;其中结合态多酚含量是游离态多酚的5倍以上,结合态类黄酮含量是游离态的2倍以上。4种豆类游离态和结合态提取物均具有良好的抗氧化活性,其中游离态提取物对DPPH自由基的清除能力明显高于结合态,而结合态对FRAP、ABTS、O2-自由基的清除能力明显高于游离态。豆类中含有丰富的酚类、类黄酮等物质,并且主要以结合态形式存在,具有较强的抗氧化活性。     

4种豆类中多酚、类黄酮含量及抗氧化活性研究

对豇豆、红小豆、绿豆和蚕豆4种豆类中游离态和结合态的多酚及类黄酮的含量进行测定,并比较了其体外抗氧化活性。数据表明,4种不同豆类的游离态多酚和结合态多酚含量范围分别为1.35~1.75mg/g和8.63~10.11 mg/g;游离态类黄酮和结合态类黄酮含量范围分别为1.58~2.07 mg/g和3.92~5.08mg/g;其中结合态多酚含量是游离态多酚的5倍以上,结合态类黄酮含量是游离态的2倍以上。4种豆类游离态和结合态提取物均具有良好的抗氧化活性,其中游离态提取物对DPPH自由基的清除能力明显高于结合态,而结合态对FRAP、ABTS、O_(2-)自由基的清除能力明显高于游离态。豆类中含有丰富的酚类、类黄酮等物质,并且主要以结合态形式存在,具有较强的抗氧化活性。     

干燥方式对柠檬片中游离态、结合态多酚及抗氧化特性的影响

采用冷冻干燥(FD)、热风干燥(AD)、红外干燥(IRD)及真空干燥(VD)对柠檬片进行干制,利用分光光度法测定游离态、结合态多酚含量及抗氧化能力(清除ABTS·+能力、铁离子还原能力和清除DPPH·能力),并采用超高效液相色谱对酚类物质进行定性和定量分析。结果表明,4种干制柠檬片结合态多酚含量、清除ABTS·+能力、铁还原能力均分别高于游离态多酚的相应含量及能力,而其游离态多酚清除DPPH·能力均低于结合态多酚。4种干制柠檬中主要酚类物质为类黄酮,其含量显著高于酚酸含量;柠檬中游离态多酚主要为橙皮苷、圣草枸橼苷和芦丁,三者含量占游离态多酚总量的91.18%～94.92%;结合态多酚主要为原儿茶酸、柚皮苷和橙皮苷,三者含量占结合态多酚总量的81.83%～83.64%。热处理对柠檬中酚类物质呈现不同影响。与FD处理相比,热处理导致柠檬中总酚、总酚酸与结合态多酚含量下降,游离态酚酸总量、生物利用多酚含量及其生物利用度上升;而结合态类黄酮总量上升,游离态类黄酮总量下降。其中3种热处理干燥方式中,AD处理组酚酸与类黄酮总量均为最高,分别为325.77 mg/100 g DW和2 317.57 mg/100 g DW。     

石榴皮游离与结合态多酚的组成和抗氧化性研究

目的:研究石榴皮游离与结合态多酚含量、组成和抗氧化性的异同,为其提取和利用提供依据。方法:将3个石榴品种的成熟果实分别制成4类皮粉,采用超声提取法和碱液溶出法制取各皮粉的游离态和结合态多酚,采用3种方法测定其酚类组成和含量,采用4种方法评价其抗氧化能力。结果:4类皮粉的游离态多酚、类黄酮和单宁含量分别为107.55~157.60mg GAE/g DW、24.24~44.54mgQUE/gDW和143.03~231.44mgTAE/gDW,结合态多酚、类黄酮和单宁含量分别为7.35~30.89mgGAE/g DW、2.25~11.56mgQUE/gDW和9.01~18.86mgTAE/g DW。全皮、外层皮、内层皮和皮渣粉的多酚含量差异显著(p0.05),其中皮渣游离态多酚含量最低而结合态多酚含量最高,各品种的同类皮粉的多酚含量有显著差别(p0.05)。同一皮粉的游离态和结合态多酚的抗氧化能力彼此相近,其大小与多酚和单宁含量均显著相关(p0.01)。结论:提取石榴皮多酚的材料可根据原料的实际状况而选全皮、内层皮或皮渣,提取游离酚可获取材料中大部分多酚。结合态多酚的抗氧化能力与游离态多酚相似但含量低。     

不同品种肉桂中酚类物质抗氧化和抑制糖消化酶活性比较研究

为研究肉桂中酚类物质体外抗氧化活性和抑制糖消化酶活性,以台湾土肉桂、清化肉桂、云野肉桂和西江肉桂4个品种肉桂为研究对象,分析其游离态和结合态多酚含量、游离态和结合态黄酮含量以及游离态和结合态多酚粗提物抗氧化能力和体外抑制糖消化酶活性,并对肉桂游离态和结合态多酚、游离态和结合态黄酮含量与其体外抑制糖消化酶活性进行相关性分析。通过UHPLC-MS/MS法对4个品种肉桂游离态酚类化合物进行分析。研究结果表明:4个品种肉桂中总多酚和总黄酮含量分别为58.99～71.62mg/g和46.49～58.05mg/g,游离态多酚和黄酮含量明显高于结合态多酚和黄酮含量;品种对肉桂的抗氧化活性和糖消化酶抑制活性影响显著,其中台湾土肉桂的抗氧化活性和糖消化酶抑制活性都显著高于其他3个品种(P＜0.05);游离态和结合态多酚含量、游离态和结合态黄酮含量与α-葡萄糖苷酶、α-淀粉酶和蔗糖酶的IC₅₀之间具有显著的负相关性(P＜0.05)。进一步通过UHPLC-MS/MS发现,原花青素类、槲皮素-3-O-葡萄糖苷和芦丁可能是肉桂抑制糖消化酶的主要活性物质。对不同品种肉桂生物活性差异的研究能够为肉桂的品种筛选、精深加工和高效利用提供理论参考。     

核桃多酚与蛋白质的作用方式及其抗氧化活性

以核桃为研究对象,将核桃碱提蛋白和酸提蛋白经溶剂作用后超滤,通过破坏核桃多酚-蛋白复合体间的作用力得到不同结合态多酚,测定多酚含量及其抗氧化活性,以期探究核桃酚类物质与核桃蛋白化学键结合机制。研究结果表明,在pH3.5和pH11条件下,游离态多酚含量分别为6.46、6.27 mg/g,占总酚含量的25.15%、29.77%,非共价结合态多酚含量分别为11.31、7.74 mg/g,占总酚含量的44.02%、36.75%,共价结合态含量7.92、7.05 mg/g,占总酚含量的30.83%、33.48%。由此可知,非共价结合为核桃多酚与核桃蛋白质的主要结合方式。在pH3.5和pH11条件下,游离态多酚对DPPH自由基的清除率分别为82.34%、43.68%,Fe2+螯合率分别为71.88%、49.96%,还原力吸光度值分别为1.157、0.857,脂质抗过氧化能力分别为47.71%、32.69%。在5种不同结合态多酚中,游离态多酚的抗氧化活性显著高于其他结合态多酚(p<0.05)。     

紫色百香果果皮多酚存在形式及抗氧化活性

以紫色百香果果皮为材料,采用两项溶剂萃取的方法提取分离百香果果皮的游离态、酯化态及结合态多酚,测定其多酚含量和体外抗氧化活性,并采用电喷雾电离质谱（electrospray ionization mass spectrometry,ESI-MS）对3种形式多酚进行成分分析。结果表明,百香果果皮中游离酚含量最多,为0.641 3 mg GAE/g DW;酯化酚次之,为0.529 0 mg GAE/g DW;结合酚最少,为0.153 3 mg GAE/g DW;游离酚、酯化酚和结合酚的DPPH自由基清除率分别为43.1%、39.5%、24.8%;铁离子还原能力（ferric ion reducing antioxidant powder,FRAP）值分别为 140、117、86 mmol/L,羟基自由基清除率分别为24.0%、22.9%、18.3%。不同存在形式百香果果皮多酚的抗氧化能力大小表现为游离酚＞酯化酚＞结合酚;百香果果皮中3种形式多酚在种类和组分上存在着很大的差异。     

鲜食玉米酚类化合物含量及体外功能活性研究

选择‘天紫23’‘西星黄糯6号’和‘京科糯2000’3个不同颜色的代表性品种，探讨鲜食玉米籽粒在鲜食期和完熟期多酚类化合物及体外功能活性的差异。结果表明，鲜食玉米籽粒中的酚酸类物质大多以结合态形式存在，黄酮和花色苷类物质则主要以游离态形式存在，且鲜食期的多酚含量均高于完熟期。鲜食期多酚提取物的羟基自由基清除率、DPPH自由基清除率和总还原能力均显著(P<0.05)高于完熟期，且多数游离酚表现出高于结合酚的抗氧化活性。3个品种鲜食期游离态和结合态酚类物质的α-淀粉酶抑制率分别是完熟期的1.3～1.5倍和1.4～1.8倍，对α-葡萄糖苷酶的抑制率则分别为1.1～1.5倍和1.5～8.1倍。鲜食玉米多酚提取物对胆酸钠的结合能力最高，游离酚和结合酚分别在172.99～219.92μmol/100 mg DW和362.48～417.16μmol/100 mg DW,3个品种鲜食期的胆酸盐结合能力均高于完熟期，结合态多酚表现了更强的胆酸盐结合能力。     

不同酿酒高粱酚类物质含量测定及抗氧化活性比较

以6种酿酒高粱籽粒为研究对象,分别比较其游离态与结合态总酚、总黄酮、酚酸物质种类及含量,并对其抗氧化活性进行 分析。 结果表明,不同酿酒高粱品种游离态总酚、总黄酮;结合态总酚、总黄酮含量分别在135.47～274.38 mgGAE/100 g、94.60～ 148.31 mg/100 g;618.27～1 383.17 mgGAE/100 g、123.06～434.84 mg/100 g。 酿酒高粱籽粒中游离态酚酸以阿魏酸、丁香酸与没食 子酸为主,平均含量分别为611.19 μg/g、380.66 μg/g、359.34 μg/g;结合态酚酸以阿魏酸、丁香酸为主,平均含量为1 608.33 μg/g、 376.78 μg/g。 酿酒高粱籽粒中游离态与结合态总酚ABTS抗氧化能力值分别占总ABTS能力值14.6%与85.4%;酿酒高粱籽粒中游离 态与结合态总酚FRAP抗氧化能力值占总FRAP能力值14.3%与85.7%。 酿酒高粱籽粒具有丰富的酚类物质,良好的抗氧化活性,且品 种间有显著性的差异（P＜0.05）。     

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