超声辅助提取菠萝蜜果皮黄酮工艺优化及体外抗氧化活性研究

采用超声波辅助溶剂法提取菠萝蜜果皮中的黄酮,研究了不同的提取溶剂、提取方式和提取工艺因素(溶剂浓度、料液比、提取时间)对黄酮提取率的影响,采用响应面实验设计和多元二次回归分析优化提取工艺。结果表明,超声辅助溶剂法提取菠萝蜜果皮黄酮的最佳工艺为丙酮浓度61%,料液比1∶25,提取时间24 min,提取温度45℃,超声功率300 W。在此条件下进行验证实验,黄酮提取率为6.92%。且该提取条件下得到的黄酮具有良好的抗氧化能力,与VC溶液和BHT溶液相比,其DPPH、羟自由基清除率IC50值分别为:粗提液VC溶液,粗提液BHT溶液,还原能力大小为:粗提液VC溶液。     

柚皮黄酮的超声辅助提取及其抗氧化性研究

以70%乙醇为提取溶剂,采用超声辅助提取技术从柚皮中提取黄酮类化合物,利用二次旋转组合设计方法探讨柚皮黄酮的最佳提取工艺,建立了黄酮提取率与超声功率、超声时间和料液比之间的数学模型;通过化学方法考查了柚皮黄酮清除超氧阴离子自由基、DPPH自由基以及羟自由基的能力.结果表明:黄酮提取率与各因素之间的关系可以表示为Y=0.5087+0.0311X1-0.0253X2-0.0289X3+0.0498X21-0.0238X1X3+0.0395X22+0.022X2X3+0.023323,由此式得出柚皮黄酮的最佳提取条件为:超声功率1250W、超声时间10min、料液比1:30(g/m1).经实验验证,柚皮黄酮的提取率可达0.734%,模型拟合度良好.抗氧化实验结果表明,柚皮黄酮具有较强的清除超氧自由基和DPPH自由基的能力,其EC50(半抑制浓度)相应为0.0906、0.0161mg/ml,分别是VC的1.9倍和3.3倍;柚皮黄酮清除羟自由基的能力较弱,其EC50为0.5649mg/ml,为VC的15.5倍.     

玫瑰黄酮的提取及其清除DPPH自由基活性研究

采用正交试验研究玫瑰黄酮的最佳提取条件,同时以VC和VE为对照,评价玫瑰黄酮清除1,1-二苯基苦基苯肼(DPPH自由基)的能力。结果表明玫瑰黄酮最佳的提取条件为:乙醇体积分数60%、液料比15:1、浸提温度40℃、提取时间1.5h,此时玫瑰黄酮提取率为40.87%、DPPH自由基清除率为88.28%。玫瑰黄酮对DPPH自由基有明显的清除作用,其对DPPH自由基的清除能力小于VC大于VE。玫瑰黄酮、VC和VE清除DPPH自由基的半数抑制浓度IC50分别为12.50、7.00mg/L和13.95mg/L。     

响应面法优化提取无花果干果中多酚和总黄酮物质及其抗氧化活性

利用响应面法优化无花果干果中多酚和黄酮物质的提取工艺,并分析其体外抗氧化活性。在单因素实验基础上,根据Box-Behnken试验设计对提取条件(乙醇体积分数、超声温度、超声时间、料液比)进行分析与优化,从而考察其对多酚及黄酮提取量的影响并进一步研究无花果干果提取物的抗氧化活性。结果显示,最佳工艺参数为:乙醇体积分数60%,超声温度51℃,超声时间52 min,料液比1∶45(g/m L)。在此工艺条件下,多酚的提取量为(2.72±0.37)mg/g,总黄酮的提取量为(20.89±0.57)mg/g。与VC进行抗氧化活性比较发现,在多酚质量浓度(2.50 mg/g)相同条件下,无花果干果中多酚提取物的还原能力、清除羟自由基率(最高为95.54%)以及清除DPPH自由基率(最高为66.73%)均高于VC,清除超氧阴离子自由基率(最高为35.15%)低于VC。在黄酮质量浓度(10.60 mg/g)相同条件下,无花果干总果黄酮提取物各抗氧化指标均低于VC。另外,人工模拟胃肠液处理对无花果干果提取物抗氧化活性的影响实验发现,经人工胃液处理后,提取液的还原能力和羟自由基清除能力明显著升高,而DPPH自由基和超氧阴离子自由基清除能力明显降低,经人工肠液处理后,相应的还原能力和超氧阴离子自由基清除能力明显升高,而DPPH和羟自由基清除能力明显下降。     

食用鼠曲草黄酮的提取及体外抗氧化性研究

对食用鼠曲草总黄酮的提取工艺和抗氧化活性进行了研究。采用微波辅助提取法,提取了鼠曲草中的黄酮类化合物。测定了鼠曲草黄酮的体外抗氧化活性,并与常见的抗氧化剂VC进行了比较。结果表明:微波功率500 W时,微波提取的最佳工艺为乙醇体积分数50%、料液比1∶60(g:mL)、温度60℃、时间6 min,在此条件下黄酮最高得率为4.63%。鼠曲草黄酮在总抗氧化能力、清除超氧阴离子自由基的能力、清除DPPH自由基的能力方面略低于抗氧化剂VC,但在清除羟自由基的能力和抑制Fe2+诱发卵黄脂蛋白过氧化的能力上鼠曲草黄酮强于VC。     

香椿叶总黄酮的超声波辅助提取及其清除DPPH自由基能力的研究

研究运用超声波辅助提取香椿叶中总黄酮的工艺条件和提取物清除DPPH自由基的能力。在单因素试验的基础上，用正交试验法对香椿叶的超声波辅助提取工艺进行优选，选用L16（4^5）进行正交试验；以黄酮提取量为主，提取物以黄酮计的清除DPPH的IC50值为次参考指标；考察乙醇浓度、固液比、超声提取时间、提取温度、提取次数对香椿叶总黄酮提取量的影响。最佳工艺条件为：25g原料，以料液比1：10加入70％的乙醇溶液，50℃下每次超声提取60min，提取4次。在此条件下，每克香椿叶可提取总黄酮22．2134mg，提取物以黄酮计的清除DPPH的IC50值为19．1327。     

“黑美人”土豆黄酮提取及抗氧化活性

对黑美人土豆黄酮提取工艺及抗氧化性进行了研究。结果表明,影响黑美人土豆黄酮提取率的主要因素为温度、料液比和乙醇体积分数;最优工艺条件为提取温度78℃、乙醇体积分数62%,料液比1:35(g/mL)。在此工艺条件下,最大响应值(1.04%)和实验测定值(1.03%)相符合,说明响应面法优化黑美人土豆黄酮是可行和有效的。黑美人土豆黄酮提取物与VC、芦丁相比较清除DPPH自由基能力大于芦丁小于VC;黄酮质量浓度在不高于20μg/mL时清除ABTS自由基的能力和抗氧化力大于VC,但始终大于同质量浓度的芦丁,结果显示黑美人土豆黄酮提取物具有显著的抗氧化活性,可以作为潜在的抗氧化剂或功能性食品资源。     

草果总黄酮的提取及DPPH自由基清除活性研究

采用超声波辅助法提取草果总黄酮,通过单因素试验和正交试验优化草果黄酮的最佳提取条件,同时以VC为对照,评价草果黄酮清除1,1-二苯基-2-苦基肼(1,1-Diphenyl-2-picryl-hydrazyl,DPPH)自由基的能力。结果表明草果黄酮的最佳提取条件为:乙醇体积分数60%、料液比1∶50(g/mL)、提取温度40℃、超声功率为160 W,提取时间60 min,此时草果黄酮提取量是24.2 mg/g。草果黄酮有较强的DPPH自由基清除力,且草果黄酮抗氧化性高于VC,其IC50分别为:IC50草果黄酮12.89 mg/L,IC50VC为6.94 mg/L,草果黄酮的DPPH自由基清除率为80.5%。     

苦荞黄酮的提取分离及抗氧化活性研究

采用正交试验研究苦荞黄酮提取过程中的浸提时间、乙醇浓度、料液比、浸提温度,得到最佳的提取条件为:提取时间5h、乙醇浓度70%、料液比1:15、浸提温度70℃。利用最佳提取条件对苦荞粉进行了苦荞黄酮的提取分离,并进行了纯化、成分分析,得到了含量高达72.32%的高纯度苦荞黄酮。以VC、芦丁为对照,研究苦荞黄酮、荞籽醇提物、荞壳醇提物在不同浓度,不同pH值下对DPPH·的清除能力。结果表明,苦荞黄酮的清除DPPH·的能力仅次于VC,大于芦丁和荞籽醇提物,远大于荞壳醇提物,清除DPPH·的能力随着浓度的增大而升高,在pH2～8范围内,随着pH值的增大清除DPPH·的能力先降低后增大,在pH7时最低。     

大米草黄酮的提取工艺及清除羟自由基作用的研究

通过单因素实验及正交实验对大米草黄酮提取工艺条件进行探讨.结果表明,大米草黄酮提取的最佳工艺条件是料液比 1:10、温度 80℃、乙醇浓度 70%、提取时间 3 h、提取3次,此条件下黄酮的提取率为 0.478%.此外.还研究了对羟自由基的清除作用,发现大米草提取物对羟自由基清除能力低于抗坏血酸.略高于芦丁.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

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 latest scientific