雨生红球藻粉虾青素的提取及稳定性研究

以雨生红球藻粉为原料,采用有机溶剂法提取虾青素并对虾青素提取液稳定性进行研究。用响应面法优化提取工艺,采用Box-Behnken设计方法研究提取温度、提取时间、料液比及其交互作用对虾青素提取量的影响。试验结果表明:最佳提取条件为:提取温度51℃,提取时间42 min,料液比1∶640 g/m L,在此条件下提取率达92.04%。虾青素的性质不稳定,易分解,在贮存过程中受到多种因素的影响。当温度低于40℃时,虾青素提取液比较稳定;在太阳光及紫外光照射下,虾青素破坏严重;Zn~(2+),Cu~(2+),Fe~(2+),Mg~(2+),Na+和Ca~(2+)对虾青素提取液都有较大影响;而抗氧化剂VC,Na_2SO_3对虾青素有破坏作用,BHT对其稳定性保护作用效果不显著。在避光条件下冷藏保存并减少与金属离子的接触,可以减缓虾青素的降解。     

克氏原螯虾虾壳中虾青素酯酶解工艺的研究

以克氏原螯虾虾壳为原料,脂肪酶为催化剂,水解虾青素酯制备游离虾青素,探讨了脂肪酶添加量、酶解温度、溶液pH及酶解时间对虾青素酯水解效果的影响。通过单因素和正交试验确定酶解最优条件为脂肪酶添加量10%、酶解温度50℃、溶液pH 5.5、酶解时间5 h,在此条件下虾青素提取量达到87.58μg/g;各因素对虾青素提取量的影响依次为:酶解时间脂肪酶添加量溶液pH酶解温度。     

虾壳虾青素的提取及其稳定性研究

目的 以虾头、虾壳为原料, 研究有机溶剂提取虾青素的条件及其稳定性。方法 采用有机溶剂提取法, 单因素实验的基础上优化虾青素提取工艺, 并用分光光度法进行含量测定, 从保存条件、光照、温度、酸度、金属离子等方面对虾壳虾青素稳定性的影响进行了研究。结果 通过数据分析得出提取虾青素的最佳条件为: 用生虾乙酸乙酯为提取溶剂, 25℃下pH 4.0的提取溶液以1:15的用量比提取2 h得到较高的提取率, 在这个条件下虾青素的产量为34.43 μg/g。光照、温度、酸度都能影响到虾壳虾青素的稳定性, 其中光照对其影响最为显著。结论 对于虾壳虾青素提取液, 在高温下不稳定; 对室外光不稳定, 对室内光较稳定; 在弱碱性环境中较稳定; 加入Fe2 、Fe3 、Cu2 、Zn2 、Ca2 、Mg2 、Na 金属离子硫酸盐溶液中, 对色素均有一定的破坏作用, 以Fe2 最为不稳定。     

雨生红球藻中虾青素的提取及稳定性研究

目的:以雨生红球藻粉为原料,研究破壁方法、有机溶剂提取虾青素的工艺条件及虾青素油中虾青素的稳定性和破壁藻粉储存条件。方法:采用机械破壁和有机溶剂提取法,在单因素实验的基础上优化细胞破壁和虾青素提取工艺,并用分光光度法进行含量测定;从温度、光照、氧气、保存条件方面对虾青素稳定性的影响进行研究。结果:通过数据分析得出高压均质最佳条件为:50MPa、3遍,破壁率为94%,提取含量为36.4μg/mg,手动匀浆处理量为0.05g,匀浆10min,可使破壁率达100%;提取虾青素的最佳条件为:采用二氯甲烷溶剂,料液比为1∶20,在20℃水浴条件下,提取3遍,每遍1h;温度、光照、氧气都能影响到虾青素的稳定性,其中氧气对其影响最为显著,雨生红球藻粉的最佳储存条件是铝箔袋真空冷藏。     

超声波提取克氏原螯虾壳中虾青素

以克氏原螯虾壳为原料,采用超声波辅助方法提取虾青素,探讨了提取剂种类、超声作用时间、超声波功率、料液比等因素对虾青素提取效果的影响。应用Box-Behnken中心组合实验和响应面分析法确定了克氏原螯虾壳中虾青素提取最佳条件为超声作用时间29.4 min、超声波功率163 W、料液比为1:18.2(g:mL),此条件下虾青素含量为62.52μg/g。     

结合型虾青素酶法水解工艺的研究

利用木瓜蛋白酶将克氏原螯虾虾壳中的结合型虾青素水解,获取游离虾青素。以虾青素提取量为评价指标,考察了蛋白酶添加量、酶解温度、溶液pH值及酶解时间等因素对水解效果的影响。通过单因素和正交试验确定了酶解工艺的最佳条件为:木瓜蛋白酶添加量10%、酶解温度45℃、溶液p H值5.5、酶解时间5 h,在此条件下,虾青素的提取量为97.26μg/g;各因素对虾青素提取量的影响依次为溶液pH值酶解温度酶解时间木瓜蛋白酶添加量。     

雨生红球藻培养及虾青素累积条件探讨

探讨了雨生红球藻(Haematoccuspluvialis)712株的适宜培养条件及藻体诱导累积虾青素的培养基条件。重点研究了温度、pH和光照条件对雨生红球藻营养生长的影响,以及NaNO3、Fe2+盐和乙酸钠浓度对雨生红球藻诱导累积虾青素含量的影响。结果表明:24℃、1000～1500lx连续光照、pH8.0左右的生长条件适合雨生红球藻游动细胞增殖,使平均生长速率达到0.252/d。通过正交试验表明:缺氮培养基对于雨生红球藻细胞累积虾青素最为有利,虾青素含量达到6.72μg/mL,而FeSO4和乙酸钠浓度对虾青素的累积无显著性影响。     

南极磷虾虾壳中虾青素稳定性的研究

为了研究南极磷虾虾壳中虾青素的稳定性,以提取液中总类胡萝卜素含量为指标,测定了其在光照、温度、酸碱、金属离子等不同条件下的保留率。结果表明,虾青素在光照条件下很不稳定,尤其在阳光直射时降解迅速;随着温度的升高,虾青素损失加快,当温度在60～90℃范围时,褪色加剧;碱浓度较低时虾青素比较稳定,过高的酸浓度或碱浓度都会引起虾青素的损失;钠、钾、镁、钙、锌和铝离子对虾青素基本没有影响,而铜、亚铁离子和铁离子有明显的破坏作用,其中铁离子对虾青素的影响最大。     

大孔树脂分离纯化南极磷虾壳中的虾青素

研究AB-8大孔吸附树脂对虾青素的静态、动态吸附效果。结果表明,AB-8树脂对虾青素的最大吸附量为476.2 μg/g干树脂,乙酸乙酯对虾青素的解吸率为98.7%;动态吸附条件为虾青素上样质量浓度2 μg/mL、上样流速4 BV/h。此条件下,皂化液中虾青素的回收率为78.9%,纯度为92.4%。     

南极磷虾粉中虾青素的提取

为优化南极磷虾粉中虾青素的提取方法,在单因素实验基础上,选取提取温度、料液比、提取时间为自变量,虾青素含量为响应值,采用中心组合(Box-Behnken)实验设计方法,研究各自变量及其交互作用对虾青素含量的影响。利用Design-Expert软件,建立了虾青素含量与提取过程中各因素的二次多项式模型,并通过响应面优化法确定虾青素提取方法的最佳条件:提取温度51.41℃、料液比63.13∶1(mL∶g)、提取时间61.15 min,此条件下虾青素含量达到最大为179.00 mg/kg。经过实验验证,南极磷虾粉中虾青素含量可达到179.21 mg/kg。     

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