木瓜蛋白酶水解克氏原螯虾虾壳提取虾青素的研究

研究以克氏原螯虾壳为原料,利用木瓜蛋白酶对其水解提取虾青素,通过单因素试验和中心点实验设计试验优化最佳酶解工艺条件。结果表明,酶解最适条件为:酶解温度48.5℃、pH值5.8、酶活力为2 522U/g、水解时间63min、配液与底物固比2∶1(g∶mL),每克湿虾壳含总类胡萝卜素115.76μg,比用酸处理法提取量提高13.82%。高效液相检测其虾青素质量浓度达到13.06g/dL,显著提高了萃取物中虾青素浓度,为虾的废弃物的综合利用提供了新的途径。     

二甲亚砜法破壁条件对法夫酵母虾青素提取效果的影响

为了评价二甲亚砜(DMSO)法破壁在法夫酵母虾青素提取中的应用价值,研究了提取溶剂、DMSO用量、破壁温度、料液比、浸提时间、浸提次数6个条件因子对破壁后法夫酵母虾青素提取的影响,并对破壁条件进行了优化。实验结果表明:丙酮为最理想的提取溶剂;各主要因素破壁温度、料液比和浸提时间对虾青素的提取量影响依次减小,单因素及正交实验得到法夫酵母中虾青素提取的最佳条件为:以丙酮为提取溶剂、DMSO用量1∶1.5、浸提2次、破壁温度45℃、料液比1∶20(w/v)、浸提时间40 min,优化后虾青素的提取量为4.42 mg/g。     

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。     

小龙虾下脚料中虾青素和甲壳素提取工艺研究

我国每年会产生大量的虾头、虾壳、虾尾等富含虾青素和甲壳素等高经济价值成分的下脚料。以小龙虾下脚料为原料进行虾青素和甲壳素的连续提取,首先对原料进行去蛋白质处理,然后采用乙酸乙酯浸提法提取虾青素,最后采用HCl/NaOH浸提法从剩余固体中提取甲壳素。通过单因素及响应面优化试验,确定最佳虾青素提取工艺条件：料液比1∶19（g/mL）、浸提时间120 min、浸提温度34℃,此条件下虾青素提取量为67.40 μg/g;最佳甲壳素提取工艺条件：HCl溶液浓度1 mol/L、HCl溶液浸泡时间20 min、NaOH溶液浓度1 mol/L、NaOH溶液浸泡时间6.5 min,此条件下甲壳素提取率为24.13%。     

超声辅助酶法水解虾头蛋白工艺优化

为提取虾头蛋白制备虾味调味品,提高虾头副产物的附加值,优化虾头酶解工艺。并探讨虾头酶解液在模拟鱼翅加工中的利用。通过超声波辅助木瓜蛋白酶法提取虾头蛋白,探讨超声功率、超声时间、粒径、酶解温度、pH值、料液比、酶添加量、酶解时间对虾头蛋白水解度的影响,通过响应面试验法优化提取工艺。通过向模拟鱼翅胶液中添加不同含量虾头酶解液的水溶液,探讨酶解液含量对模拟鱼翅感官的影响。超声波辅助酶法提取虾头蛋白的最佳提取条件为:按料液比1∶10(g/mL),酶添加量8 000 U/g,粒径0.2 mm~0.3 mm的虾头中添加木瓜蛋白酶,调节pH值至7.5,在超声功率120 W条件下处理20 min后,60℃下酶解时间3 h,此条件下虾头蛋白的水解率可达65.25%(以虾头蛋白质量计)。添加80%虾头酶解液制备的模拟鱼翅已具备较优的感官特性。     

丰年虫卵中类胡萝卜素的提取工艺研究

采用木瓜蛋白酶破壁与有机溶剂浸提相结合的方法从丰年虫卵中提取类胡萝卜素。通过单因素实验和正交实验,考察酶解pH、酶解温度、酶用量、酶解时间及浸提溶剂用量等因素对提取效果的影响。结果表明,利用酶解与有机溶剂浸提法提取丰年虫卵类胡萝卜素的最佳工艺条件为:调节木瓜蛋白酶pH至6,酶用量为375U/g,在60℃下酶解25min,再采用30mL/g的丙酮浸提。在此条件下,丰年虫卵中类胡萝卜素的提取率为0.03mg/g。     

酶法提取怀菊花总黄酮工艺研究

用正交实验确定酶法提取怀菊花总黄酮的最佳提取工艺条件为:料液比为1∶ 10,酶解温度45 ℃,pH=6.2,纤维素酶用量0.25 g/L,果胶酶用量0.3 g/L,酶解时间150 min,浸提时间60 min,浸提液体积40 mL.在此条件下怀菊花总黄酮的得率可达6.83%.     

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。     

响应面法优化南极磷虾壳中虾青素提取条件的研究

以南极磷虾壳为原料,采用响应面法研究虾青素的最优提取条件,为南极磷虾的加工利用提供依据。以虾青素提取率为指标,在单因素实验基础上确定实验因素及其水平,并设计三因素三水平响应面实验,研究料液比、提取温度和提取时间对提取率的影响。结果显示,最佳工艺条件是料液比为1：5（g／mL）、提取温度为30℃、提取时间为7h,提取级数为2级,此实验范围内虾青素的提取率达到最大值131．56μg／g。     

酶法提取浒苔多糖工艺优化的研究

以浒苔为原料,研究浒苔多糖的热水浸提-木瓜蛋白酶联合提取工艺.在单因素试验的基础上采用正交试验设计,对浒苔多糖的提取条件进行优化.结果表明,提取温度80 ℃,提取时间4 h,料液比1∶50 g/mL,提取2次的条件下,热水浸提效果最佳.木瓜蛋白酶用量8%,酶解温度60 ℃, 酶解时间2 h,料液pH 5.5的条件下,酶解效果最佳.浒苔多糖得率为27.75%,粗多糖纯度为50.03%.     

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