黑曲霉发酵法辅助提取芒萁黄酮及其抗氧化研究

该试验旨在确定黑曲霉发酵法辅助提取芒萁黄酮的最佳提取工艺,并探讨其抗氧化性。采用黑曲霉发酵法制备混合酶液的方法,通过单因素试验、正交试验确定提取芒萁黄酮的最佳条件,并通过测定芒萁黄酮对羟基自由基、DPPH的清除作用和还原力的分析,对其抗氧化活性进行研究。结果表明,黑曲霉发酵法制备复合酶液,提取芒萁黄酮的最佳条件为加酶量2.5mL,pH 5.0,于70℃下酶解2h;黑曲霉产复合酶辅助提取率最高,由不加酶的6.66%提高到11.67%,芒萁黄酮提取物有良好的清除羟基自由基的能力。     

甘蔗叶黄酮分离纯化工艺及生理活性研究

实验以甘蔗叶为原料,研究黄酮类化合物分离纯化工艺,并研究甘蔗叶黄酮对羟自由基(·OH)、超氧自由基(O2-·)和亚硝酸盐(NO2-)的清除能力。结果表明,利用超声波辅助提取,甘蔗叶黄酮最佳提取工艺为乙醇浓度80%,提取温度60℃,超声提取时间60min,料液比1∶40,超声波功率为104W,该工艺制备得到的甘蔗叶黄酮提取量为22.13mg/g。甘蔗叶黄酮粗提物对自由基和亚硝酸盐均具有较强的清除作用。采用AB-8大孔树脂进行纯化,纯化条件为上样浓度1.9mg/mL,上样流速1mL/min,流量为3BV的70%乙醇洗脱。     

微波-纤维素酶联合提取芒萁黄酮及抗氧化研究

目的:研究微波-纤维素酶联合提取芒萁总黄酮的最佳工艺条件。方法:利用微波消解仪辅助提取,主要研究微波处理时间、微波功率、微波压强、料液比等单因素对芒萁中的总黄酮提取得率的影响;采用纤维素酶提取,主要研究纤维素酶浓度、酶解时间、pH、酶解温度对提取芒萁黄酮提取效果的影响。在单因素实验基础上,通过三元二次旋转设计实验,确定最佳提取条件。结果:以60~80目的芒萁叶干粉为原料,水为提取剂,料液比为1:30,用微波消解仪(微波工作压强0.3MPa,微波功率682W)处理92s后,采用纤维素酶处理,用0.10%的纤维素酶,于59℃酶解2h,提取效果最好。在最佳条件下,黄酮的提取率为11.35%;该提取物对羟基自由基、超氧自由基都有一定的清除作用。结论:芒萁中的黄酮含量高,原料易得,有很高的开发利用价值。     

蜂蛹黄酮的提取及体外抗氧化作用的研究

研究了利用超声波技术对蜂蛹黄酮的辅助提取工艺及提取物的体外抗氧化作用.结果表明,超声波辅助提取蜂蛹黄酮时间短、效果好.最佳提取工艺条件为:提取溶剂为甲醇,超声波强度34W/cm2,超声波处理时间20min,料液比1:15.黄酮的一次提取量为43.85mg/100g.蜂蛹黄酮对碱性邻苯三酚自氧化产生的超氧阴离子、Fenton反应产生的羟基自由基和Fe2 诱发卵黄低密度脂蛋白(LDL)多不饱和脂肪酸(PUFA)过氧化产生的烷氧基(LO·)和烷过氧基(LOO·)均有明显的抑制作用,且均呈现一定的量效关系.     

响应面法优化葡萄籽黄酮提取条件及其抗氧化性研究

采用响应面分析法优化微波-超声波联合提取野生葡萄籽中黄酮的条件。利用Box-Behnken组合设计研究了料液比、乙醇浓度、超声波处理时间、微波处理时间4个因素对黄酮提取率的影响。结果表明:乙醇浓度和微波处理时间对响应值影响极显著(p<0.001)。在采用微波功率(中火)、超声功率100 W、35℃条件下,葡萄籽黄酮的最佳提取工艺条件为料液比1︰40、乙醇浓度73%、超声波处理时间20 min、微波处理95 s。在此条件下葡萄籽黄酮提取率达2.86 mg/g。进一步对葡萄籽黄酮的抗氧化性进行测定,结果表明:葡萄籽中黄酮类化合物对羟基自由基(·OH)的清除能力比维生素C高约9倍;还原能力也大于维生素C。     

黑花生衣中黄酮类物质的提取方法研究

研究超声波辅助提取黑花生衣中黄酮类化合物的工艺条件,探讨乙醇浓度、料液比、提取时间、提取温度、pH对提取效果的影响。确定影响黄酮提取效果的最主要因素是料液比,并得出黑花生衣中黄酮类化合物在超声波频率为50 kHz条件下提取的最佳工艺条件为:提取溶剂为60%乙醇,提取时间45 min,提取温度40℃,料液比1∶300(g/mL),pH2.5。在此基础上,通过测定黑花生衣提取液对活性自由基的清除作用,探讨其抗氧化活性。结果表明,黑花生衣中黄酮类化合物对羟基自由基(·OH)、和DPPH·自由基皆具有显著的清除作用,且其清除作用与浓度之间呈量效关系。     

超声波协同提取隐囊蕨黄酮物质及其抗氧化的研究

采用超声波协同提取隐囊蕨中黄酮物质,最佳提取条件为:在溶剂量(50%的乙醇)为80倍的情况下,超声波处理20min,在95℃下提取2h,黄酮得率为5.79%.隐囊蕨的黄酮提取液对羟自由基、超氧自由基有良好清除作用,并能有效阻断猪油的氧化.     

香菇总黄酮的超声波辅助提取及抗氧化性能研究

采用超声波辅助提取法提取香菇中的黄酮类化合物,通过单因素实验和正交实验设计对香菇总黄酮的提取工艺条件进行优化,并通过体外清除羟自由基(·OH)和超氧阴离子自由基(O_2~-·),评价香菇总黄酮的抗氧化性能。结果表明,乙醇体积分数对香菇总黄酮提取具有显著性影响,香菇总黄酮超声波辅助提取的最佳工艺条件是:乙醇体积分数60%,料液比1∶30(g∶m L),超声浸提温度65℃,浸提时间60min,黄酮提取率为0.802%±0.018%。香菇总黄酮对·OH和O_2~-·均具有一定的清除作用,其对·OH的清除作用强于同浓度的VC,对O_2~-·的清除作用略低于VC。     

藿香叶黄酮提取工艺优化及其体外抗氧化活性

对藿香叶黄酮提取工艺及体外抗氧化活性进行研究。应用微波辅助乙醇提取法提取保山藿香叶中的黄酮,并通过单因素实验和L₉(34)正交设计对提取工艺进行优化,并以抗坏血酸为对照,对其还原力及羟自由基(·OH)、1,1-二苯基-2-三硝基苯肼自由基(DPPH·)及2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+·)活性的清除能力进行探讨。结果表明:藿香叶黄酮提取的最佳条件为料液比1:60 g/mL,乙醇浓度60%,微波功率567 W,提取时间70 s,提取得率可达6.11%。此条件下得到的藿香叶黄酮提取物清除几种自由基的能力良好,尤其对ABTS+·清除能力最优,对·OH、DPPH·和ABTS+·IC₅₀分别为281.89、3.57、1.52 mg/L。     

陕西苦菜叶总黄酮的提取及抗氧化活性的测定

苦菜总黄酮的提取及抗氧化活性的研究可提高我国野生资源利用和活性成分的开发.以苦菜为原料,采用超声波辅助提取法对苦菜叶总黄酮的提取工艺进行优化,采用分光光度法测定提取物的还原力,对羟基自由基(·OH)、超氧阴离子(O2-·)、DPPH自由基(DPPH·)的清除作用进行研究.结果表明:超声波辅助提取的优化工艺参数为乙醇体积分数80％、提取温度70℃、料液比1∶35、超声时间40min,此条件下总黄酮的提取含量为64.62mg/g.苦菜叶黄酮对羟基自由基、超氧阴离子、DPPH自由基具有良好的清除能力,同时还具有较强的还原能力,活性大小与提取物的浓度呈明显的线性关系.     

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.     

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     

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     

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,     

Anti-mutagenic compounds from corn

In previous studies with aflatoxin-contaminated corn an uncharacteristic response for AFB₁ in the Salmonella/microsomal mutagenicity assay (Ames test) was observed and the presence of anti-aflatoxin factors in the corn was suggested. In the current study, corn was extracted and fractionated using thin layer chromatography (TLC) using different developing solvent systems and the Ames test was used to monitor for anti-mutagenic activity in the corn fractions. Both Salmonella tester strains TA98 and TA100 with metabolic activation (S9) were used. Several corn fractions, at different stages in the isolation and purification process, showed anti-mutagenic dose-responses when exposed to pure AFB₁. Corn extracts were non-toxic to the tester strains and TLC fractions that showed the best anti-mutagenic dose-responses were selected for further partial characterization analyses.