沙田柚皮中柚皮苷和果胶综合提取工艺研究

本研究利用柚皮苷、果胶性质的差异,探索了沙田柚皮中柚皮苷、果胶综合提取工艺。即先以沙田柚皮粉为原料,采用乙醇法提取沙田柚皮中柚皮苷,起到脱色、除杂的目的,且柚皮中原有的可溶性果胶损失少。再以脱柚皮苷后的沙田柚皮粉为原料,采用酒石酸法提取果胶。酒石酸可高效地催化沙田柚皮中的原果胶发生水解转化为可溶性果胶,此外酒石酸具有螯合钙、镁等金属离子作用,有利于果胶溶出,提高果胶的提取率。研究结果为,以沙田柚皮粉为原料,乙醇法提取柚皮苷的优化工艺为:固液比为1∶10,乙醇浓度为70%,提取温度为40℃,提取时间为60min。以脱柚皮苷的沙田柚皮粉为原料,酒石酸法提取果胶的优化工艺为:提取液pH为1.5,固液比为1∶20,提取温度为95℃,提取时间为2h。     

超声波辅助酸法提取柚皮果胶生产工艺的研究

以柚皮为原料,研究了料液比、超声功率、超声温度、超声时间对柚皮果胶提取得率的影响,在单因素试验的基础上通过正交试验设计优化柚皮果胶的提取工艺条件。结果表明,柚皮果胶提取的最佳工艺条件:料液比1 g∶15 m L,超声功率150 W,超声温度为80℃,超声时间为40 min。采用优化工艺提取果胶,产品总得率达22.76%。     

响应面优化提取血柚皮果胶的工艺研究

采用响应面法优化了血柚皮果胶的提取工艺,在单因素实验基础上,选取柠檬酸浓度、提取温度、液料比和提取时间为自变量,果胶得率为响应值,根据Box-Behnken实验设计方法,对提取血柚皮果胶的关键因素参数进行了优化,建立了血柚皮果胶得率的数学模型。结果表明:四个因素对血柚皮果胶得率的影响大小依次为提取温度柠檬酸浓度液料比提取时间;血柚皮果胶提取的最佳工艺参数为:柠檬酸浓度1.5%,提取温度82℃、液料比32∶1m L/g、提取时间99min。在此条件下,血柚皮果胶得率达18.85%,与预测值仅相差0.32%,验证了数学模型的有效性。     

超声波辅助提取柚皮中的果胶

我国柚子资源丰富,除果肉供食用外,柚皮常作为废弃物丢弃。柚皮中含有黄酮、果胶、香精油、膳食纤维素等多种活性成分。本文以柚皮为原料,在超声波辅助下,采用酸提醇沉法从柚皮中提取果胶。以果胶得率为指标,分别考察了超声波处理时间、超声波功率、液料比及提取温度等因素对果胶得率的影响。在单因素试验的基础上,进行正交实验设计,对柚皮果胶提取工艺进行优化。结果表明,超声波辅助提取柚皮果胶的最佳工艺条件为:超声波功率400W,超声波处理时间20min,料液比1∶25,提取温度85℃。该条件下,柚皮果胶平均得率为20.9%,比传统的酸提取法提高了43.1%。利用超声波辅助提取柚皮果胶,时间短、得率高,具有很好的实际应用价值,可为柚子资源的综合开发利用提供参考。     

螯合剂协同微波法提取枇杷皮果胶的工艺研究

以六偏磷酸钠为萃取剂,采用微波提取枇杷皮果胶,通过单因素试验和正交法优选,确定了枇杷皮果胶提取的最优工艺条件。结果表明:加入0.3%含量的六偏磷酸钠螯合剂辅助微波法提取果胶的最佳工艺参数为:料液比为1∶15(g/m L)、p H值为1、微波功率为600 W、微波时间为3 min,果胶产率达7.75%。     

超临界萃取柚皮精油的研究

本研究以柚皮精油的最大提取率为目标,研究了超临界CO2萃取柚皮精油的提取工艺,分析了萃取压力、萃取温度、萃取时间对柚皮精油提取率的影响,并通过正交试验得到了最佳的提取条件：萃取压力为30MPa,萃取温度为40℃,萃取时间为3h。在此条件下柚皮精油的萃取得率为1.72%。对超临界萃取柚皮精油进行物理化学分析和GC-MS分析表明,超临界萃取柚皮精油工艺稳定可靠,具有极高的应用价值。     

响应面分析法优化超声波辅助提取柚皮果胶工艺的研究

在超声条件下,研究无机酸种类、p H、超声时间、液料比、提取温度、超声功率等因素对柚皮果胶提取率的影响,通过响应面设计确定最优的超声波辅助提取柚皮果胶工艺参数。结果表明:在选用盐酸作为水解酸时,最佳工艺参数为p H为2.5,液料比为1∶40(g/m L),超声波处理时间为55 min,提取温度为60℃,超声功率为320 W,实测柚皮果胶得率为24.02%。     

柚皮果胶提取工艺研究进展

主要综述了酸水解法、超声波提取法、微波提取法、亚临界水萃取和酶提取法对柚皮果胶提取工艺的研究进展，为研发新型、环保、健康的果胶提取工艺提供理论依据。     

柚子果皮的综合利用

利用正交实验法地色素的提取，果胶的提取和果胶的沉淀进行了试验，得出了最佳工艺条件。最后得到了柚皮精油，柚皮黄色素和果胶三种产品。     

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％.     

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