黑果腺肋花楸黄酮提取工艺优化及体外抗氧化研究

应用黑果腺肋花楸作为原料,采用响应面法优化黑果腺肋花楸黄酮提取工艺,并利用V_C做对照试验,对其还原力及以及·OH、O_2~-·、DPPH自由基清除力进行研究。结果表明,最佳工艺参数为乙醇浓度77.67%、提取时间81 min、料液比1∶20(g/m L),在此条件下,黑果腺肋花楸黄酮得率5.14%。影响黑果腺肋花楸黄酮得率因素由大到小依次为乙醇浓度提取时间料液比。最佳工艺参数提取的黑果腺肋花楸黄酮对·OH、O_2~-·、DPPH自由基的IC_(50)分别为3.27、3.96、3.79 mg/m L,最大清除率达29.58%、70.23%、61.41%,并且其还原能力强,能够说明其体外抗氧化活性较强。     

牦牛乳及其制品中苯甲酸来源分析及影响因素研究

该文以鳞尾木为试材,在单因素试验基础上应用响应面分析法对鳞尾木总黄酮的提取工艺进行优化并研究其体外抗氧化活性,另对广西四个地区内鳞尾木总黄酮含量进行测定比较。试验结果表明:最佳提取条件为超声波功率(330 W),超声频率(35 kHz),乙醇浓度(80%),料液比(1∶41.8 g/mL),提取温度(64.6℃),提取时间(50.7 min),此条件下总黄酮得率为2.83%。此外鳞尾木总黄酮对·OH、O_2~-·、DPPH·均能够起到清除作用,当黄酮浓度为1 mg/mL时,对·OH、O_2~-·和DPPH·的最大清除率分别为13.27%、30.98%、38.68%,具有较好的还原能力,广西玉良的鳞尾木总黄酮含量及抗氧化活性要优于其他3个地区。     

响应面优化紫果西番莲多糖提取工艺及抗氧化活性研究

以紫果西番莲为研究对象,采用单因素试验和响应面分析法优化紫果西番莲果肉多糖的提取工艺,考察液料比、超声时间、超声功率和超声温度对其多糖提取量的影响;以清除DPPH自由基和·OH能力评价紫果西番莲果肉多糖的抗氧化活性。结果表明:紫果西番莲果肉多糖最佳提取工艺为:液料比5 mL/g、超声时间20 min、超声功率330 W和超声温度70℃,测得紫果西番莲多糖的提取量为98.82 mg/g;紫果西番莲果肉多糖有一定的DPPH自由基和·OH的清除能力,其清除DPPH自由基、·OH的半抑制浓度(IC50)分别为66.97μg/mL和0.23 mg/mL。     

超声辅助提取蓝靛果果实多糖的优化及清除自由基活性研究

该文在单因素试验的基础上,利用响应面法优化超声波辅助蓝靛果多糖提取工艺。统计分析结果表明影响蓝靛果多糖提取率大小因素依次为:提取时间超声功率液料比。最佳提取条件为:时间41 min,液料比为41∶1(mL/g),超声功率310 W。在此条件下,多糖得率为(8.31±0.23)%。清除自由基试验结果表明,蓝靛果多糖对DPPH·、O_2~-·均有一定的清除作用,最大清除率分别为(53.92±0.88)%和(67.79±1.01)%,半抑制率浓度IC_(50)分别为5.40 mg/mL和0.28 mg/mL。     

黄芥籽粕黄酮提取及其抗氧化活性

以黄酮得率为考察指标,通过单因素实验结合响应面分析的方法,优化了黄芥籽粕中黄酮超声辅助提取工艺,并采用清除DPPH·和·OH法测定其抗氧化活性。结果显示:黄芥籽粕黄酮超声辅助提取最佳工艺条件为:乙醇体积分数71%,料液比(g/mL)1∶16,超声功率280 W、提取温度30℃,提取时间41 min。在此工艺条件下,黄芥籽粕黄酮得率为10.042 mg/g,与理论预测值10.134 mg/g的相对误差为0.91%。黄芥籽粕黄酮与BHT清除DPPH·的IC_(50)分别为3.80、6.21μg/mL;清除·OH的IC_(50)分别为2.18、5.87μg/mL。表明响应面法优化的黄芥籽粕黄酮超声辅助提取工艺稳定可行,黄芥籽粕黄酮具有强的抗氧化活性。     

超声波辅助溶剂法提取山茱萸黄酮工艺及体外抗氧化活性研究

以山茱萸为原料,采用超声波辅助溶剂法提取黄酮,以黄酮得率为指标,在单因素试验基础上,进行Box-Behnken试验,基于BP神经网络和遗传算法对提取工艺进行优化;通过测定山茱萸黄酮提取液还原力、清除DPPH·及·OH的能力,评价其体外抗氧化活性。结果表明,超声波辅助溶剂法提取山茱萸黄酮较优工艺为：超声功率390W,超声时间29min,乙醇浓度55%,料液比1∶25(g/mL)。在此条件下,山茱萸黄酮得率可达22.12mg/g。山茱萸黄酮具有较强的自由基清除能力及体外抗氧化活性。研究结果为山茱萸黄酮作为新型天然食品抗氧化剂在食品工业领域的应用提供了理论参考,为山茱萸资源的高值化利用提供了科学试验依据。     

芹菜渣水溶性膳食纤维的抗氧化活性研究

研究以微波辅助法提取的芹菜渣水溶性膳食纤维(SDF)为原料,研究其对·OH、O_2~-·和DPPH自由基3种自由基的清除作用、铁还原能力和对芝麻油的抗氧化效果。试验结果表明,芹菜渣SDF对·OH和O_2~-·、DPPH·均有一定的清除能力;SDF对羟自由基的清除效果最明显,对超氧阴离子自由基O_2~-·的清除能力较弱;在其质量浓度为6 mg/mL时对·OH和O_2~-·、DPPH·的清除率分别达到95.6%,15.6%和35.9%;芹菜渣SDF还具有一定的还原能力和对芝麻油较好的抗氧化作用。     

樟头红青皮总酚超声波提取工艺及其抗氧化性分析

采用超声波辅助提取樟头红青皮总酚,通过单因素试验,结合响应面法,确定了樟头红青皮总酚的最适提取工艺,并通过4个抗氧化体系(DPPH,ABTS~+,·OH,还原能力)来评价其抗氧化活性。结果表明:樟头红青皮总酚的最适提取工艺条件为乙醇浓度56.2%、料液比1:52、超声时间22.5 min、超声功率108.3 W、提取2次,此条件下总酚得率为25.04 mg/g。樟头红青皮总酚对DPPH、ABTS~+、·OH自由基的清除能力和还原能力低于Vc,差异极显著(P0.01);樟头红青皮总酚对DPPH、ABTS~+自由基的清除能力很强,半抑制浓度分别为1.160 mg/mL和1.477 mg/mL;在一定浓度范围内,樟头红青皮总酚浓度越高,其对·OH自由基的清除能力和还原能力越强。     

谷芽多糖的提取工艺及其抗氧化活性研究

优化超声法提取谷芽多糖,研究谷芽多糖的体外抗氧化活性。通过单因素试验和正交试验,研究料液比、超声功率、超声提取温度和超声作用时间对谷芽多糖提取效果的影响。分别采用紫外分光光度法和邻苯三酚自氧化法测定其清除DPPH·和O_2~-·的作用进行试验,根据试验结果评价其体外抗氧化活性。得出优化工艺条件为料液比1:35(g/mL,),提取温度70℃,超声功率180 W,作用时间20 min。谷芽多糖的得率为20.85%优选谷芽多糖的超声提取工艺,省时、高效、可靠、重现性好;体外抗氧化性试验显示谷芽多糖对DPPH·和O_2~-·具有较强的清除能力,且在一定范围内其抗氧化作用与浓度呈现良好的量效关系。     

阿魏菇多糖超声微波辅助提取及其抗氧化活性

以阿魏菇作为原料,水作为提取溶剂,通过响应面优化超声-微波协同辅助提取阿魏菇多糖工艺,并和传统水浴浸提法进行比较,采用清除DPPH·、·OH和O_2~-·模型对其体外抗氧化活性进行评价。结果表明:超声-微波辅助提取阿魏菇多糖的最佳的工艺条件为:料液比1∶50(g/m L),提取时间10 min,微波功率60 W。与传统水浴浸提法相比,超声-微波辅助提取缩短了提取时间,阿魏菇多糖的得率由2.23%增加到5.6%。超声-微波协同辅助提取对阿魏菇多糖的结构基本没有影响。阿魏菇多糖具有较强的清除DPPH·、·OH和O_2~-·的能力,并与质量浓度呈一定正相关关系,当阿魏菇多糖质量浓度达到5 mg/m L时,对DPPH·、·OH和O_2~-·的清除率分别达到67%、59%和63%,但弱于VC的抗氧化活性。     

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