响应曲面法优化茶皂素提纯工艺研究

本文主要以有机溶剂法浸提油茶籽外壳粉得到的粗提液作为原料,应用絮凝-沉淀法提纯皂素。在单因素试验的基础上,利用Mintab15.0软件得到回归方程的预测模型并进行响应面分析,确定利用絮凝-沉淀法提纯皂素的最优工艺条件。絮凝试验:加入16%的壳聚糖溶液和皂素损失率为28.46%,杂质损失量为1.39%;沉淀试验:氧化钙加入量1.78%、沉淀温度32.75℃和沉淀时间3.01h,沉淀率为98.99%;释放试验:释放温度52.2℃、释放时间3.17h和碳酸氢铵加入量4.09%,释放率为3.61%。最后,在最优提纯工艺条件下测得纯度为60.4%。     

絮凝-沉淀法制备油茶皂素工艺研究

以水酶法制取油茶籽油后的水相为原料,采用絮凝-沉淀法提取其中的油茶皂素.单因素实验得出适宜的絮凝条件为:1％的壳聚糖溶液加入量为水相体积的16％,此时油茶皂素的损失率为22.24％.应用正交实验确定沉淀-转化的最佳工艺为:在絮凝离心分离后的水溶液中,加入质量3％的氧化钙,在20℃下沉淀6h,离心后,加入转化剂碳酸氢铵(加入量为2.5倍的氧化钙量),40℃下释放0.5h,最终得到纯度为80.25％的油茶皂素.此法在提高产品纯度的同时,浓缩了油茶皂素水溶液,降低了能耗.     

复合酶法提取薯蓣皂素的研究

该文探索了复合酶法提取薯蓣皂素的新工艺.考察了反应时间、加酶量、反应温度、pH值、搅拌转速等因素对提取薯蓣皂素产率的影响.通过正交试验设计对薯蓣皂素提取率影响较大的4个因素:反应时间、反应温度、pH值、搅拌转速进行优化,得到复合酶法提取薯蓣皂素的最优工艺条件为50℃,pH值为5,搅拌转速25r/min,反应时间30h.在此条件下,薯蓣皂素的提取率为4.88％.     

油茶饼粕茶皂素与多糖综合提取工艺

以油茶脱脂饼粕为原料,对其茶皂素和多糖的综合提取工艺进行研究。采用有机溶剂浸提法先提取茶皂素,再提取多糖,并分别采用单因素试验和正交试验探讨其最佳工艺条件。结果表明,提取油茶饼粕皂素的最佳工艺条件为乙醇浓度80%、料液比1:9(g/mL)、提取时间4 h、提取温度90℃,在此条件下茶皂素提取率为8.98%;提取油茶饼粕多糖的最佳工艺条件为提取温度70℃、料液比1:30(g/mL)、提取时间4 h,在此条件下多糖提取率为5.88%。     

用壳聚糖除杂从油茶籽工艺水中提取油茶皂素的研究

以油茶皂素的提取率作为响应值,用响应面法对既能充分发挥壳聚糖凝聚油茶籽工艺水中杂质,又不影响油茶皂素提取的工艺条件进行优化。在考虑壳聚糖浓度及添加量、反应时间及温度、搅拌速度等因素对油茶皂素提取率影响的基础上,筛选出主要影响因素即壳聚糖添加量、反应时间、反应温度进行正交试验,通过响应面分析,得出3种因素的相互作用及最佳提取条件。结果表明,在壳聚糖浓度为0.05%,搅拌速度为10 r/min,壳聚糖添加量为17.8 m L,反应温度为50.1℃,反应时间为16.6 min的优化条件下,油茶皂素提取率为84.97%。     

茶籽中茶皂素的提取工艺研究

探讨了茶皂素提取的工艺条件,实验结果表明,乙醇浓度、温度、时间、料液比对茶籽仁中茶皂素的提取有显著的影响;确定茶皂素的最佳提取工艺为:90%～95%乙醇溶液为浸提液,料液比为1∶10～12,浸提时间为2h,浸提温度为80～90℃,用丙酮作沉淀剂。     

茶籽中茶皂素的提取工艺研究

探讨了茶皂素提取的工艺条件,实验结果表明,乙醇浓度、温度、时间、料液比对茶籽仁中茶皂素的提取有显著的影响;确定茶皂素的最佳提取工艺为:90%～95%乙醇溶液为浸提液,料液比为1∶10～12,浸提时间为2h,浸提温度为80～90℃,用丙酮作沉淀剂。      

有机相中麦芽糊精疏水改性工艺的研究

以麦芽糊精为原料,对有机相中麦芽糊精疏水改性的最佳工艺进行研究.结果表明,当麦芽糊精的质量浓度为30%、溶剂为95%的乙醇、辛烯基琥珀酸酐的用量为糊精干基的6%时,加碱量对酯化反应的影响最大,各因素的重要性依次为:加碱量、反应温度、反应时间.高取代度辛烯基琥珀酸淀粉酯的最佳工艺条件为:反应温度33℃,反应时间3.0h,...     

水相酶解极性有机溶剂提取茶籽油工艺的研究

研究了不同条件下的水相酶解极性有机溶剂提取茶籽油工艺。采用乙醇为浸提剂同时提取油茶籽仁中的油脂和茶皂素,通过正交实验优化了提取工艺,结果表明,V_(乙醇)∶V_水=1∶2.5,料液比=1∶4,反应温度55℃,反应时间1.5 h。在此条件下,茶籽油的单次提油率58.91%,3次总提油率为99.82%,同时总粗茶皂素得率39.48%。该方法简单高效地得到了高品质的茶籽油,并且同时获得附加值高的副产物茶皂素,具有很高的实用价值。     

磷脂酶A1催化水解大豆浓缩磷脂的研究

研究了反应温度、加酶量、底物比(水/磷脂,mL/g)、反应时间对磷脂酶A1水解大豆浓缩磷脂的影响.采用正交设计方法,确定了各因素影响的显著性顺序为:底物比>反应温度>反应时间>加酶量;磷脂酶A1水解大豆浓缩磷脂的最佳工艺条件为:反应温度40℃,加酶量600μL,底物比12,反应时间10h.最佳工艺条件下产物酸值达129.6mgKOH/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