火龙果果实甜菜苷类色素组成与分布

目的：明确火龙果果实中甜菜苷类色素（BLs）组分构成及其部位归属。方法：采用超高效液相色谱飞行时间质谱法对3类火龙果果实\[红皮红肉型（RR）、红皮白肉型（RW）和黄皮白肉型（YW）\]的果肉部位和果皮部位甜菜苷类色素（BLs）进行筛查和结构确证。结果：3类火龙果果实中共鉴定出甜菜苷、丙二酰甜菜苷和梨果仙人掌黄质等19种组分,RR火龙果的果皮部位鉴定的BLs组分最多（14种）,其次是RR果肉部位（12种）及RW果皮部位（9种）。结论：RR火龙果果实BLs组分最为丰富,RW次之,YW最少;BLs主要分布在红色果肉和红色果皮部位,在白色果肉和黄色果皮部位则较少。果肉、果皮部位检测出BLs组分分别为12,16种。     

纤维素酶协同超声波辅助乙醇提取红肉火龙果色素工艺的优化

分别以火龙果果皮、果肉冻干样品为原料,采用响应面法优化纤维素酶协同超声波辅助乙醇提取火龙果果皮、果肉色素工艺。火龙果果皮色素的最佳提取工艺为超声时间24min、超声温度39℃、超声功率325 W、乙醇浓度23%,得率为(81.661 3±0.762 0)mg/100g;火龙果果肉色素的最佳提取工艺条件为超声时间34min、超声温度41℃、超声功率315 W、乙醇浓度23%,得率为(278.660 4±1.084 2)mg/100g。     

红肉火龙果中两种甜菜苷色素稳定性研究

探索红肉火龙果色素稳定性的影响因素,进而确定火龙果色素的最佳储存条件。以红肉火龙果果肉为原料,采用高效液相检测红肉火龙果中5-O-β-葡萄糖-甜菜苷和5-O-β-葡萄糖-异甜菜苷色素含量,研究温度、pH、光照、氮气对其稳定性影响。5-O-β-葡萄糖-甜菜苷和5-O-β-葡萄糖-异甜菜苷色素的热稳定性差,温度越高越不利于色素稳定;pH在4~6时色素最稳定;光照和氧气都可降低色素的稳定性;充氮气有利于色素的稳定性。火龙果饮料等制品的储藏过程中应注意冷藏避光、适宜pH下密封储存,可适量填充氮气。     

火龙果果皮中甜菜红素的提取、鉴定及金属离子对其稳定性的影响

目的:为火龙果源甜菜红素在食品加工中的应用提供理论支持。方法:首先以红肉火龙果果皮为原料，探究浸提液、料液比、浸提液pH值、温度和时间对甜菜红素得率的影响，以优化其提取条件，进而采用UPLC-MS分析纯化后提取物中甜菜红素的含量和结构，最后评价金属离子Cu2+和Fe2+对其稳定性的影响。结果:火龙果果皮中甜菜红素最优提取条件为:采用蒸馏水提取，料液比1∶5，pH 5，温度30 ℃，提取60 min。所得提取物中甜菜红素的含量为95.2 mg/g，含有6种甜菜红素单体，其中，丙二酰甜菜苷和甜菜苷为两种主要单体，分别占46.5%和34.4%。CuSO4和FeCl2干扰甜菜红素的稳定性，即使0.05 mg/mL CuSO4也会造成甜菜红素溶液颜色改变和特征吸光值降低；当FeCl2超过0.10 mg/mL时，甜菜红素溶液的颜色变化趋势加快。结论:红肉火龙果果皮可作为甜菜红素的良好来源，提取工艺简单可行。金属离子Cu2+和Fe2+不利于甜菜红素的稳定性，在加工贮藏过程中应避免与铜制、铁制器具接触。     

两种火龙果果皮红色素提取工艺优化及其抗氧化活性

以红肉红皮(RP)和白肉红皮(WP)火龙果果皮为原料,采用超声波辅助乙醇浸提法提取火龙果果皮红色素,并对其粗提物进行鉴定,通过单因素与正交试验优化提取工艺,同时测定两种果皮红色素提纯物质的总还原能力和自由基抗氧化活性。结果表明,经光谱法和HPLC-MS/MS联用法双重检测,火龙果果皮红色素为甜菜红素。WP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:40 (g/mL)、超声时间25 min、超声温度40 ℃,色素最大得率为0.856%。RP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:30 (g/mL)、超声时间15 min、超声温度30 ℃,色素最大得率为0.915%。RP以其纯化工艺流程获得的提纯物产量是WP的1.232倍。在一定浓度范围内,WP和RP火龙果果皮甜菜红素都有较强的总还原能力,但略低于V_C,清除DPPH·自由基、羟自由基(·OH)的IC₅₀分别为1.15和0.95 mg/mL、5.95和4.57 mg/mL,两者对亚硝酸根(NO₂-)最大清除率分别为22.90%和25.10%,红肉火龙果果皮甜菜红素的综合抗氧化能力优于白肉红皮品种。     

红心火龙果果肉中活性成分与其抗氧化能力的相关性研究

为探讨红心火龙果活性成分与抗氧化能力相关性,以8种红火龙果肉为材料,测定甜菜红素、总酚及黄酮含量,测定总抗氧化、清除DPPH·、ABTS+·、·OH及NO₂-·自由基能力,并进行相关性分析,HPLC和HPLC-MS分离鉴定甜菜红素组分,PLSR研究色素组分含量与抗氧化活性的相关性。结果表明:8个火龙果样品中甜菜红素、总酚和黄酮含量存在差异,"海南金都1号"火龙果甜菜红素和黄酮含量均最高,分别为76.77和9.00 mg/L,"广西大红龙"中总酚含量最高达53.01 mg/L。除·OH清除能力外,甜菜红素与其他4种抗氧化能力呈极显著正相关(r=0.936~0.955)。黄酮与抗氧化能力较显著相关(r=0.717~0.956),而总酚与抗氧化能力无显著相关性(P>0.05)。液质鉴定甜菜红素组分有Betanin、Isobetanin、Phyllocactin和Isophyllocactin,Betanin是抗氧化的重要成分,Phyllocactin其次,可能是Phyllocactin的丙二酰基与苯环邻位酚羟基产生分子内氢键,抑制酚羟基的氧化性。     

HPLC-MS法分离鉴定土人参色素组成

采用液质方法(HPLC-MS),将土人参色素不同组分分离,并对其进行结构鉴定.结果表明:土人参茎和果中色素均为甜菜苷类色素,从土人参茎中分离出五种甜菜苷色素,果中分离出六种,其中五种是二者均有,分别为甜菜苷5-O-β-葡萄糖、甜菜苷6-O-β-葡萄糖、异甜菜苷6-O-β-葡萄糖、2-脱羧基-甜菜苷-6-O-(6’-0-阿魏酰)-β-葡萄糖苷、5,6-二吲哚乙酸-5-O-β-葡萄糖苷.新甜菜苷5-O-β-葡萄糖苷仅存在于土人参果中,在茎中未发现.各组分在土人参茎和果中所占百分数均不同,使二者光谱特征等性质不同.     

红肉与白肉火龙果酚酸组成及其抗氧化活性

为研究火龙果果皮、果肉中的酚酸组成及抗氧化活性,以红肉火龙果和白肉火龙果为研究对象,采用高效液相色谱法(HPLC)测定其游离型酚酸(FPA)、可溶共价结合型酚酸(HPA)和束缚型酚酸(BPA)组分与含量,并测定其体外抗氧化活性,包括DPPH清除能力、还原能力和羟自由基抑制能力。结果表明:两种火龙果中酚酸含量顺序为:红肉果肉 > 白肉果肉 > 白肉果皮 > 红肉果皮。火龙果果肉中酚酸主要以HPA形式存在,果皮中酚酸的主要存在形式为BPA。没食子酸是红肉火龙果中的主要酚酸(1700.70 μg/g干重);原儿茶酸是白肉火龙果中主要酚酸(1877.50 μg/g干重)。红肉果皮的BPA对DPPH自由基清除能力最强(2206.37 mg/L),红肉果肉的HPA还原能力最强(A₇₀₀=0.82),白肉果皮的HPA对羟自由基抑制能力最强(77.50 U/mL)。酚酸含量与抗氧化活性的相关性分析表明:DPPH自由基清除能力和还原能力与酚酸的含量呈极显著(P<0.01)正相关,羟自由基抑制能力与酚酸含量无显著相关性。     

阴香果实花色苷提取工艺研究

阴香成熟果实果皮黑紫色,鲜果花色苷含量1.127%。提取阴香果实花色苷前先将果实煮沸、搅拌。阴香鲜果沸水内煮沸12min,果实裂口率为99%,经搅拌后果肉组织解体、果肉果核分离。阴香果实处理后的物料以70%乙醇溶液、pH3、料液比1∶2(w/v),以温度40℃、浸泡20min浸提花色苷,3次浸提花色苷提取率97.15%。     

火龙果不同部位发酵后活性成分含量和抗氧化活性

以红心火龙果和白心火龙果为原料,测定不同种类和部位火龙果(红心火龙果果肉,red flesh,RF;白心火龙果果肉,white flesh,WF;红心火龙果果皮,red peel,RP;白心火龙果果皮,white peel,WP)发酵液中总酚、总黄酮含量及抗氧化活性(总抗氧化能力、还原能力和羟自由基清除能力),考察酚类物质含量与抗氧化活性的相关性。结果表明:不同种类和部位火龙果发酵液中总酚、总黄酮含量及抗氧化活性存在显著性差异,且RP发酵液表现出最高的总酚(636.63 mg/L)、总黄酮含量(452.42 mg/L)及最强的总抗氧化能力(相当于V_C浓度169.32 mg/L)、还原能力(140.29 mg/L)和羟自由基清除能力(96.65%);总酚、总黄酮含量与总抗氧化能力、还原能力和羟自由基清除能力之间呈正相关,表明总酚类物质是火龙果中抗氧化成分。     

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