微波预处理-超声波提取山茱萸多糖及稳定性研究

以汉中山茱萸为原料,通过单因素及正交试验确定微波预处理-超声波提取山茱萸多糖的最佳工艺为:提取时间80 min,提取温度60℃,料液比1∶14(g/mL),醇沉浓度65%,多糖提取率达到16.83%。多糖提取物的稳定性实验结果表明,山茱萸中多糖在K+、Ca2+、Na+、Fe3+、Cu2+、柠檬酸钠、VC及氧化还原剂中稳定性较差,在Al3+、苯甲酸钠、酸性溶液中稳定性较好。     

白扁豆多糖的超声波辅助提取及其稳定性研究

采用超声波辅助提取,研究提取温度、时间、料液比及提取次数对白扁豆多糖提取率的影响,并对多糖在不同温度、pH和常见的氧化剂、还原剂、食品添加剂、金属离子等条件下的稳定性进行探讨.实验结果表明,白扁豆多糖的最佳提取条件为:超声提取温度60℃、提取时间30min、料液比1∶30 (g∶ mL)、提取次数2次.白扁豆糖在低温、还原剂、VC及pH=5～7的溶液中稳定性较好,在氧化剂、苯甲酸钠、柠檬酸和K+、Na+、Ca2+、Al3+等金属离子溶液中的稳定性相对较差.     

白及多糖的提取工艺及其生物活性研究

研究白及的微波预处理-超声波提取工艺优化及其生物活性。以白及胶得率和多糖得率的总评归一值为考察指标,采用正交试验设计优选白及的微波预处理-超声波提取工艺条件,并研究白及多糖的稳定性和清除亚硝酸盐活性。最佳工艺条件为:微波时间90 s、解析剂比4∶1(mL/g)、料液比1∶25(g/mL)、超声波功率100 W、提取时间20 min,此时白及胶得率为12.343%,白及多糖得率为7.081%,且对比研究表明,微波预处理-超声波提取法优于单独超声提取法;稳定性试验表明:白及多糖在还原剂、柠檬酸及中性溶液中的稳定性较好,而在Ca~(2+)、Al~(3+)、Na~+、Fe~(3+)、山梨酸钾、过酸性或过碱性溶液中的稳定性较差;亚硝酸清除研究表明:白及多糖具有一定的清除亚硝酸盐活性,在试验范围内,亚硝酸盐的清除率可达48.3%,可作为天然的亚硝酸盐清除剂。微波预处理-超声波提取法具有省时高效等特点,白及多糖稳定性和亚硝酸盐清除活性研究可为白及多糖的综合利用提供参考依据。     

兰州百合鳞茎多糖超声波辅助提取工艺优化及稳定性研究

以兰州百合废弃鳞茎为原料,通过正交试验对超声波辅助提取兰州百合多糖的工艺进行优化,并考察了兰州百合多糖的稳定性。结果表明:超声波辅助提取兰州百合多糖的最佳工艺条件为料液比1:20(g/mL),超声时间60min,超声温度60℃,超声功率250W,该条件下兰州百合多糖提取率为18.44%。多糖提取物抗氧化性较差,易被H_2O_2氧化,但具有良好的抗还原性。     

超声波提取玛咖多糖的工艺研究

研究了超声波、热水和微波方法提取玛咖多糖的效果和液料比、温度、时间、功率等因素对提取玛咖多糖的影响,通过正交实验得出了超声波提取的最佳工艺条件。结果表明,不同提取方法对玛咖多糖的提取效果为超声波>微波>热水;超声波提取的影响因素顺序为温度>功率>时间,其最佳提取条件为料液比1:20、时间20min、温度50℃、功率200W,此条件下玛咖多糖的提取率为74.4%。     

超声波辅助提取芝麻叶多糖工艺研究

采用加热回流提取法和超声波辅助提取法对芝麻叶多糖进行了提取。确定影响芝麻叶多糖得率的主次因素顺序为料液比、提取时间、提取温度。芝麻叶多糖回流提取工艺条件为:提取温度90℃,提取时间120 min,料水比1∶20(g/m L)。在该条件下芝麻叶多糖的提取率为5.89%。而超声波辅助提取最佳条件是超声波功率600 W条件下处理时间30 min,在此条件下芝麻叶多糖提取率可达到7.56%。     

红雪茶色素提取工艺及稳定性研究

确定红雪茶色素的最佳提取工艺,并对其稳定性进行研究。以浸提法对红雪茶色素进行提取,在单因素试验的基础,通过对提取剂、料液比、提取温度、提取时间4因素进行L9(34)正交试验得到最佳提取条件,并对红雪茶色素在不同温度、pH、金属离子、氧化还原剂和食品添加剂等条件下的稳定性进行研究。结果表明红雪茶色素的最佳提取条件为提取剂1.5%的盐酸乙醇溶液、料液比1∶10(g/mL)、在60℃水浴中浸提30 min;该色素在低温、中性、弱酸、弱碱条件下稳定性较好,金属离子Ca2+,K+,Cu2+,Mg2+及还原性物质对红雪茶色素稳定性影响较小,但温度大于60℃,强酸,强碱,Zn2+,Na+,Fe2+,Fe3+,氧化性物质,苯甲酸钠等溶液中稳定性较差。     

超声波辅助提取紫薯多糖工艺优化的研究

为了研究超声波辅助提取紫薯多糖的最佳工艺,在超声波频率60Hz下,考察超声波功率、提取温度、提取时间、液料比等4个单因素对紫薯多糖得率影响的基础上,采用响应面分析法对紫薯多糖的超声波辅助提取工艺进行优化。结果表明,紫薯多糖超声波辅助提取的最佳工艺条件为:超声波功率270W、提取温度44℃、提取时间84min、液料比46:1(m L/g),在此条件下,多糖得率为8.45%~8.75%,与理论预测值一致。与传统热水浸提法、超高压辅助提取法相比,采用超声波法的紫薯多糖得率分别提高了341.03%和46.01%。这表明,超声波辅助提取工艺可以有效地提取紫薯多糖。     

超声波辅助提取板栗多糖的工艺研究

应用超声波辅助水提醇沉的方法对板栗多糖的提取工艺进行研究。通过单因素试验和正交试验研究了料液比、超声波功率、超声波处理时间、提取温度、提取时间等因素对板栗多糖提取效果的影响,结果表明,各因素影响作用大小的顺序依次为:提取温度超声波处理时间超声波功率料液比提取时间。超声波辅助提取板栗多糖的最佳工艺条件为:料液比1∶25(g/mL),超声波功率200W,超声波处理时间24min,提取温度80℃,提取时间2.5h,在此条件下板栗多糖的得率为14.20%。     

超声波辅助提取西洋参多糖及功能饮料的制备

采用超声波辅助提取西洋参多糖,确定西洋参多糖提取的最佳工艺条件。并以西洋参粗多糖为主要原料,添加菊花,枸杞,白砂糖,蜂蜜等辅料,生产西洋参多糖功能饮料,对饮料色泽、气味、滋味进行感官评价,确定西洋参多糖功能饮料的最佳配方。结果表明:(1)西洋参多糖最佳提取工艺为:超声功率200 W,超声时间15 min,料液比1∶30(g/mL),浸提温度80℃,浸提时间2 h。(2)西洋参多糖功能饮料的最佳配方为(按100 mL计):西洋参多糖提取液的添加量为4 mL,枸杞提取液添加量为25 mL,菊花添提取液加量为15 mL,蜂蜜添加量为2 g,白糖添加量为2 g。     

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