正交试验优化杏酱酶解液脱色工艺

以脱色率和酸损失率为指标,比较8种脱色剂对新疆杏酱酶解液的脱色效果,筛选出较好的脱色剂为粉末活性炭。通过单因素试验考察活性炭用量、温度、时间对脱色效果的影响,并通过正交试验对该条件进一步优化,得出最佳脱色工艺条件为活性炭用量1.2g/100mL、脱色温度70℃、脱色时间60min。在此条件下,杏酱酶解液脱色率为93.01%,酸损失率为5.89%。     

新鲜菊苣提取和纯化菊粉的工艺

研究比色法测定菊粉含量的方法,并采用正交设计优选了从新鲜菊苣根中热水浸提菊粉的提取工艺条件和脱蛋白以及脱色的最佳条件。实验结果表明,菊粉提取的最佳工艺条件为:料液比1∶1,浸泡时间40 min,加热浸提温度为100℃,加热浸提时间40 min,菊粉的提取率达14.74%;脱蛋白时菊液与活性炭的最佳比例为1∶1.5;提取液最佳脱色工艺条件为:脱色温度70℃,脱色时间50 min,活性碳用量为30 g/L,脱色率为74.36%。     

野生火棘果中果胶的提取及脱色研究

以野生火棘果渣为原料,采用酸水解法提取其中的果胶,通过正交试验得到最佳提取条件。试验结果表明,酸水解法提取野生火棘果果胶的最佳提取条件是:料液比1:9,提取温度90℃,提取时间60min,pH2,提取2次。在此条件下果胶产率为7.23%。采用活性炭作脱色剂,通过研究得到最佳脱色条件:活性炭用量1.0g/100mL,脱色时间15min,脱色温度65℃。     

响应面法优化海参多肽脱色工艺

为除去海参多肽中有色物质以利于生物活性肽的分离纯化,经酶解法制备海参多肽酶解液,以脱色率和多肽回收率为评价指标,考察不同脱色剂对海参多肽酶解液的脱色效果,从中筛选出XX型粉末活性炭。在单因素试验的基础上,利用响应面法对脱色条件进行优化。最佳脱色条件为:活性炭用量0.9 g/100 mL,时间32 min,温度50℃,pH 2.2,在此条件下,海参多肽液的脱色率达到(85.39±2.25)%,多肽回收率达到(88.57±1.86)%,与理论值无显著差异。     

响应面法优化拟微绿球藻藻油脱色工艺

以海洋微藻拟微绿球藻中提取的富含二十碳五烯酸的粗藻油为原料,探究脱色材料及脱色工艺对粗藻油脱色效果的影响。在单因素试验结果的基础上,以脱色剂用量、脱色温度、脱色时间为影响因素,以藻油脱色率和藻油回收率为响应值,应用Box-Behnken试验设计建立数学模型,进行响应面分析,优化脱色工艺条件。结果表明,活性炭对拟微绿球藻藻油的脱色效果最好,响应面优化的最佳脱色工艺条件为:活性炭用量3.8 g/100 mL、脱色温度68℃、脱色时间54 min。在此条件下,微藻藻油的脱色率达到98.05%,经3次解吸后,藻油总回收率达到81.45%。     

明胶酶解液脱色工艺研究

以粉末状活性炭为脱色剂,明胶复合酶解液在不同条件下进行了脱色研究.通过单因素试验和正交试验,确定最佳工艺条件为:活性炭用量为1.5%(w/w),pH为5.5,温度35℃,脱色时间为40 min,胶原蛋白酶解液脱色效果明显,脱色率为86.21%,肽损失率为6.12%.     

啤酒废酵母蛋白液的制取及其精制

啤酒废酵母自溶后的蛋白溶液经提纯、除杂、脱色等工艺可以得到一种以多肽为主要组分的蛋白水解液,试验结果表明,啤酒废酵母自溶的最佳条件为pH值6.0,温度45℃,NaC1用量4.0%,自溶时间60h,氨基酸态氮含量为405mg/100mL。除杂最佳条件是将酵母蛋白液pH值调至2.5,离心(3000r/min)5min,此时,核酸去除率为13.59%。脱色最佳工艺条件是将自溶蛋白液pH调至6.5,以2mL/min流速流经装有活性炭的离子柱(30 mm×300mm),脱色率达到69.57%。     

亚硝酸盐含量测定过程中的脱色条件优化

目的 研究并优化饲料中亚硝酸盐含量测定过程中的脱色材料与脱色条件。方法 以脱色率和亚硝酸盐加标回收率为考察指标, 比较粉末活性炭、颗粒活性炭、硅藻土3种脱色剂的脱色效果, 确定一种较好的脱色剂, 并通过单因素实验, 优化脱色剂的脱色条件。结果 粉末活性炭脱色效果优于其他2种脱色剂。其最佳工艺条件为: 脱色剂用量2 g, 超声波水浴温度50 ℃, 超声波水浴时间30 min, 在最佳工艺条件下, 饲料脱色率可达到49.0%, 亚硝酸盐回收率可达95.15%。结论 优化后的脱色条件解决了深色饲料影响亚硝酸盐测定显色的问题, 确保了检测结果的准确性。     

银杏花粉粗多糖脱色工艺研究

为优选银杏花粉粗多糖的脱色材料,以多糖保留率和脱色率为考察指标,通过比较聚酰胺、树脂、粉末活性炭和颗粒活性炭四种不同的脱色剂的脱色效果,选择一种较好的脱色剂进行单因素和正交试验。结果表明：颗粒活性炭优于其他3 种脱色剂,通过正交试验法研究脱色条件,颗粒活性炭脱色最佳工艺参数为脱色时间4h、脱色温度50℃、脱色剂用量0.15g/ml。     

龙须菜寡糖发酵液的脱色工艺优化

为提高龙须菜寡糖的纯度,采用糖用活性炭作为脱色剂对龙须菜发酵液的脱色条件进行了探索。首先通过单因素试验考察了脱色时间、温度、震荡转速、活性炭用量等条件对龙须菜发酵液脱色效果的影响。其次通过正交试验得出,糖用活性炭用量浓度为0.4 g/100 m L,脱色时间30 min,脱色温度25℃,震荡速200 r/min等条件下可获得脱色率85.57%,寡糖回收率92.68%。在脱色率较高的同时保证了寡糖的得率,取得了良好的脱色效果。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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