核桃壳色素提取工艺及其应用性能表征

采用超声辅助提取核桃壳色素,在单因素试验的基础上,运用响应面法优化工艺条件。通过测定色素溶液对金属离子稳定性、DPPH自由基清除能力、还原力来进行色素性能表征。单因素试验确定乙醇浓度、提取时间、提取温度为主要影响因素。利用响应面法结合实际操作,确定最优工艺条件：乙醇浓度47%、提取温度51℃、提取时间55 min,最优条件下色素产率为 1.65%。对所提取的色素进行性能表征,结果表明：Mg2+、Na+、Al3+、Zn2+、Ca2+、K+对色素溶液无影响,Fe3+、Cu2+可使色素溶液沉淀。色素实际浓度为12.5 μg/mL时对DPPH自由基清除率可达73%,其有一定还原能力但与抗坏血酸相比较弱。     

紫甘薯色素提取工艺条件的优化

以紫甘薯为试材,采用响应面实验设计的方法研究其色素最优提取工艺条件。结果表明:最优紫甘薯色素提取条件为提取温度77.79℃,提取时间20.76min和液料比37.25(mL/g)。验证实验结果表明:实测值与预测值相一致,在最优的紫甘薯色素提取工艺条件下,色素色价达到最大值205.81U/mL。     

紫甘薯色素水提工艺参数的研究

采用水溶液提取紫甘薯色素.选择pH值、料液比、浸提时间和浸提温度作为单因素进行梯度试验,确定其条件范围,通过正交试验确定紫甘薯色素提取的最佳工艺条件:pH值3(HCl)、料液比1∶2(g/mL)、浸提时间2h、温度25℃,共提取3次,紫甘薯色素提取率可达94.85％.     

超声辅助提取野菊花黄色素及其稳定性研究

用体积分数95%的乙醇对野菊花的黄色素进行超声提取,在不同超声频率、提取温度、料水比、提取时间等条件下对野菊花黄色素的提取工艺进行研究,并对色素在不同温度、光照、pH值、氧化剂、还原剂、食品添加剂以及一些金属离子条件下的稳定性进行研究。结果表明,该色素适宜提取工艺为:超声频率45 kHz,提取温度为60℃,料水比为1∶50(g∶mL),提取时间为50 min。野菊花黄色素的耐光性差,耐热性较好,在酸性、还原剂、苯甲酸钠中的稳性较差,在碱性、氧化剂、Vc、柠檬酸、葡萄糖溶液中稳定性较高,色素对多数金属离子溶液的稳定性较高,K+、Fe3+、Al3+对色素有一定的减色作用。     

紫甘薯花色苷的提取及稳定性研究

采用酸化水法提取紫甘薯中的花色苷,通过单因素试验研究了提取溶剂、温度、时间和料液比对紫甘薯花色苷提取量的影响,并对紫甘薯花色苷提取液在不同温度、pH、Na2SO3、糖类和光照条件下的稳定性进行了研究。研究结果表明,紫甘薯花色苷的最佳提取条件为:0.5%的盐酸水溶液作提取溶剂、温度60℃、料液比1∶20(g/mL)、时间1 h,在此条件下提取1次时花色苷含量达43.890 1 mg/100 g(鲜重)。紫甘薯花色苷不耐高温,在光照和蔗糖、麦芽糖、葡萄糖、果糖等条件下稳定性较高,但在Na2SO3及碱性条件下不稳定。     

蓝莓色素的超声提取工艺及稳定性

在单因素试验基础上,采用中心组合设计方法优化蓝莓色素的超声提取工艺,并分析色素的稳定性。结果表明：蓝莓色素超声提取工艺的最佳条件为乙醇体积分数45%、料液比(g/mL)1:13、超声温度55℃、pH4.5、超声功率450W、超声时间50min。在此条件下,蓝莓色素提取率为274.36U/g。蓝莓色素耐热,在K+、Na+、Mg2+ 等金属离子以及山梨酸钾等食品添加剂条件下稳定性较高,而在Zn2+、Fe2+、Fe3+、Ca2+ 及碱性环境条件下不稳定。     

水提紫甘薯色素废渣总黄酮提取工艺研究

目的研究水提紫甘薯色素废渣总黄酮的提取工艺,旨在为紫甘薯废渣的综合开发利用提供理论基础和参考依据。方法采用溶液浸提法、超声波辅助法、微波萃取法对水提紫甘薯色素废渣中的总黄酮进行提取研究,通过单因素实验和正交实验确定最佳提取方法及工艺条件。结果水提紫甘薯色素废渣总黄酮最佳提取方法为微波萃取法,其最佳提取工艺:乙醇体积分数70%,提取时间4 min,微波功率708 W,料液比1:40。在此条件下累计6次提取结果得水提紫甘薯色素废渣中总黄酮含量为3.83 g±0.03 g/100 g。最佳提取次数为2次。结论水提紫甘薯色素废渣黄酮类物质含量较高,具有较大的开发利用价值。     

天然食用色素紫甘薯花青素的稳定性研究

采用乙醇浸提法提取紫甘薯花青素,考察了紫甘薯花青素的稳定性。紫甘薯花青素是水溶性色素,具有较强的耐热性,避光保存花青素的稳定性最好。食品防腐剂对紫甘薯花青素的稳定性无明显影响;葡萄糖、蔗糖对花青素有一定的护色作用;VC对紫甘薯花青素影响较明显;H2O2,Cu2+和Fe2+对紫甘薯花青素的稳定性影响较大,其中Cu2+,Fe2+会使花青素溶液变浑浊。     

紫甘薯色素稳定性的探究

对不同条件下紫甘薯色素的稳定性进行探究,研究温度、光照、p H值、金属离子、H2O2、食品添加剂、食盐、蔗糖对紫甘薯色素稳定性的影响规律。结果表明:常温或冷冻、酸性环境、适量的Na Cl、蔗糖以及部分金属离子的存在对紫甘薯色素稳定有保护作用;强氧化剂、高温会使色素稳定性变差;光照对色素稳定性的影响不大;苯甲酸有一定的护色作用,没食子酸丙酯对紫甘薯稳定性影响不大。     

紫甘薯色素稳定性的探究

对不同条件下紫甘薯色素的稳定性进行探究,研究温度、光照、p H值、金属离子、H2O2、食品添加剂、食盐、蔗糖对紫甘薯色素稳定性的影响规律。结果表明:常温或冷冻、酸性环境、适量的Na Cl、蔗糖以及部分金属离子的存在对紫甘薯色素稳定有保护作用;强氧化剂、高温会使色素稳定性变差;光照对色素稳定性的影响不大;苯甲酸有一定的护色作用,没食子酸丙酯对紫甘薯稳定性影响不大。     

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