火龙果皮中果胶的提取及其结构研究

进行火龙果皮中果胶提取工艺研究,并对优选工艺下提取的果胶进行结构研究。实验结果得出果胶优选提取工艺为料液比1∶7,提取液pH为2.0,提取温度90℃,提取时间90min。在该提取工艺条件下果胶提取率为91.58%,果胶得率为2.34%,果胶提取较充分。果胶甲氧基含量为4.836%,酯化度为29.57%,属于低酯果胶;果胶重均分子量87166,数均分子量59137,为分子量相对较小的果胶。     

从柠檬皮中分离提取果胶的研究

本文探讨了酸水解法从柠檬皮中提取果胶的工艺,通过分析提取果胶的影响因素,并由正交实验法确定提取柠檬果胶的最佳工艺条件.     

豆腐柴叶果胶的提取与理化性质分析

为探究10月份豆腐柴叶果胶含量与品质,优化果胶提取工艺,提升豆腐柴开发利用效率。首先利用单因素实验比较酸提取法和超声波辅助提取法对果胶提取率的影响,再根据Box-Behnken实验设计原理,对酸法提取果胶工艺进行响应面优化,最后对两种提取工艺得到的果胶进行分离和理化性质比较。结果表明,酸提取法较好,最佳工艺条件为:料液比1∶30,提取温度88℃,提取时间2.2 h,溶液p H1.6,该条件下果胶提取率为10.57%。紫外光谱和红外光谱发现豆腐柴果胶结构与橘皮果胶结构一致。酸法果胶总半乳糖醛酸含量高于超声波辅助提取法,p H、酯化度与橘皮果胶相似,灰分、钙含量高于橘皮果胶,所有指标均达到了行业标准。      

超声波辅助提取火龙果皮中的果胶

探索不同提取条件对火龙果皮中果胶提取率的影响,以获得果胶的最佳提取条件和提取率。以干燥后的火龙果皮为原料,采用超声波辅助提取火龙果皮中的果胶,以果胶提取率作为测定指标,通过单因素实验和正交试验,确定提取果胶的最佳工艺。结果表明用超声波提取火龙果皮中果胶的最佳提取工艺为:料液比为1∶20、超声波功率为180W、提取时间为60min、提取温度为50℃。在最佳提取工艺下,果胶的提取率高达12.65%,为火龙果皮果胶的开发应用提供了理论依据。     

响应面法优化超声波辅助提取橘皮中果胶类化合物

通过正交实验结合响应面法对超声波辅助酸解提取橘皮中果胶类化合物的提取工艺进行研究,探讨果胶类化合物提取的最佳工艺条件.结果表明:超声波辅助酸水解提取可以提高橘皮果胶类化合物的得率.提取液pH、超声波频率和提取温度对最终的果胶类化合物得率影响较大,其中提取液pH影响最为显著.响应面法优化后果胶的最佳提取工艺条件为:pH1.0、超声波频率20.7kHz、提取温度73℃,此时果胶类化合物得率可达18.2%.     

柑橘皮果胶的改进提取工艺研究

以新鲜柑橘皮为原料,采用高速匀浆提取和对残渣进行酸水解再次提取的两步法提取工艺制备匀浆果胶和酸水解果胶产品。通过单因素试验和正交试验确定了匀浆提取和酸水解提取的最佳工艺参数并对果胶的脱色和分离方法进行了相关研究。实验结果表明,采用改进工艺提取后柑橘果胶产品总得率比普通一次性酸水解制备工艺明显提高;采用活性炭和聚酰胺为脱色剂进行果胶脱色可以有效提高脱色效果。     

芦荟中分离提取果胶的研究

本文探讨了用酸提醇沉淀法从芦荟中提取果胶的工艺条件,通过在不同提取条件下测定果胶的提取量,得出用酸提醇沉淀法从芦荟中提取果胶的最佳工艺条件.     

石榴皮色素的提取及果胶制取的工艺研究

目的研究提取石榴皮色素和果胶的工艺。方法用索氏提取法提取色素,酸提取乙醇沉淀法制取果胶。结果提取红色素的最佳工艺条件是:以50%乙醇为提取剂,料液比1∶4,提取温度80℃;残渣经过酸提取乙醇沉淀法制取果胶。结论工艺简单可行。     

乳酸提取柠檬皮果胶的工艺

以柠檬皮为原料,采用有机酸水解乙醇沉淀对柠檬果胶的提取工艺进行研究.通过单因素试验考察影响果胶提取的主要因素及最佳水平范围,通过正交试验确定了柠檬果胶的乳酸提取最佳工艺条件:以乳酸为提取剂,提取液pH2.0,提取温度95℃,提取时间2h,液固比30:1(mL/g).按此优选最佳工艺试验柠檬皮果胶平均收率23.8％.果胶纯度80.8％,酯化度72.7％.     

南瓜粉中果胶的提取工艺

从脱色后的南瓜粉中提取果胶 ,利用乙醇进行沉淀。就提取工艺参数对果胶的得率和胶凝度进行了研究。利用正交实验 ,确定了果胶提取的最优工艺条件     

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