昆仑雪菊多糖抗氧化及对α-淀粉酶和α-葡萄糖苷酶的抑制

为了研究新疆昆仑雪菊水溶性多糖的体外抗氧化活性以及对α-淀粉酶、α-葡萄糖苷酶的抑制作用.通过采用水提醇沉得到昆仑雪菊多糖.通过昆仑雪菊多糖对超氧阴离子自由基、DPPH自由基、OH自由基、ABTS自由基清除作用及对α-淀粉酶、α-葡萄糖苷酶抑制作用研究结果表明,昆仑雪菊多糖清除DPPH自由基、超氧阴离子自由基、OH自由基、ABTS自由基的半抑制浓度（IC50）分别是0.939 4 mg/mL、1.172 2 mg/mL、0.595 9 mg/mL、0.8164 mg/mL,但都没有阳性对照BHT清除效果好,而昆仑雪菊多糖对α-淀粉酶、α-葡萄糖苷酶的抑制效果要好于阳性对照.     

水果酵素体外抗氧化及抑制α-淀粉酶和α-葡萄糖苷酶活性的研究

为明确水果酵素在自然发酵过程中体外抗氧化活性和对α-淀粉酶、α-葡萄糖苷酶的抑制作用,以DPPH自由基清除能力和ABTS自由基清除能力为指标,研究酵素的抗氧化活性;以可溶性淀粉和4-硝基苯基-α-D-吡喃葡萄糖苷(PNPG)为底物测定酵素对α-淀粉酶和α-葡萄糖苷酶的抑制作用。试验结果表明,酵素在发酵结束后DPPH自由基清除率和ABTS自由基清除率分别达到87.19%和100.00%;对α-淀粉酶和α-葡萄糖苷酶的抑制率分别达到99.57%和81.67%。酵素对DPPH自由基、ABTS自由基的清除作用和对α-淀粉酶、α-葡萄糖苷酶的抑制作用明显,表明具有较好的抗氧化活性和降血糖潜力。     

余甘子多糖体外降血糖及抗氧化活性研究

为测定余甘子多糖降血糖及抗氧化活性,采用体外化学模型研究余甘子多糖对α-淀粉酶、α-葡萄糖苷酶抑制活性及对羟自由基(·OH)、超氧自由基(O_2~-·)、1,1-二苯-2-苦肼自由基(DPPH·)的清除作用。结果表明,余甘子多糖对两种酶具有剂量依赖性抑制活性,其最大抑制率均高于阿卡波糖;自由基清除测定表明余甘子多糖清除率总体上弱于维生素C,但高浓度时对DPPH·的清除作用与维生素C相当。余甘子多糖具有一定的降血糖和抗氧化活性,有很好的开发价值。     

白茅根多糖抗氧化活性及抑制α-葡萄糖苷酶活性研究

研究了白茅根多糖的抗氧化活性和对α-葡萄糖苷酶的抑制活性,以总还原能力、ABTS自由基清除率、羟基自由基清除率3项指标来评价白茅根多糖的抗氧化活性,并与VC进行比较,采用体外α-葡萄糖苷酶抑制模型,测定白茅根多糖对α-葡萄糖苷酶的抑制作用。结果表明,白茅根多糖的还原能力低于VC,对ABTS自由基有较好的清除作用,IC50为0.029 8 mg/mL,对羟基自由基有清除作用,IC50为1.1 mg/mL。白茅根多糖对α-葡萄糖苷酶的抑制作用较低。     

芫荽水提物的体外抗氧化活性和抑制α-葡萄糖苷酶作用的研究

研究芫荽籽水提物和成熟芫荽茎叶水提物的体外抗氧化活性和抑制α-葡萄糖苷酶的作用效果。实验测定了提取物中的总黄酮含量,以体外清除羟自由基、DPPH自由基和还原能力的效果来评价两种水提物的抗氧化能力以及对α-葡萄糖苷酶的抑制效果,从而评价其体外降血糖活性,确定了酶的抑制作用类型。结果显示:成熟芫荽茎叶水提物的总黄酮含量要高于芫荽籽水提物,两种水提物的体外抗氧化能力和α-葡萄糖苷酶的抑制效果均呈现出浓度依赖性,且前者总体抗氧化能力和酶抑制效果更优。     

蛹虫草多糖的酶法修饰及其抗氧化活性

为了提高蛹虫草多糖的抗氧化活性,采用α-淀粉酶对蛹虫草多糖进行酶法修饰。以DPPH自由基清除率为响应值,运用响应面分析法对α-淀粉酶修饰蛹虫草多糖的工艺进行优化,研究酶修饰后蛹虫草多糖清除DPPH自由基、螯合Fe2+和还原力等抗氧化活性,并对其三螺旋体结构进行分析。结果表明:对修饰多糖抗氧化活性的影响因素从大到小依次为:加酶量、酶解温度、酶解pH值;α-淀粉酶修饰蛹虫草多糖的最优工艺条件为:酶解温度48.5℃、酶解pH 5.8、加酶量259.5U/g,在此条件下,酶修饰后蛹虫草多糖对DPPH自由基的清除率预测值为81.4%,验证值为(81.6±1.6)%,结果重现性好,可用于实际预测。抗氧化实验表明,α-淀粉酶法修饰后,蛹虫草多糖清除DPPH自由基和螯合Fe2+的EC50值分别为:0.0247、1.0120mg/mL,分别比酶法修饰前提高了55.1%和39.8%;同时,蛹虫草多糖的还原力也得到了显著提高(P<0.05)。三螺旋体结构分析表明,蛹虫草多糖经α-淀粉酶修饰后,其三螺旋体结构有轻微破坏,但仍然保持三螺旋体结构。     

康定灵芝功效成分分析及体外抗氧化、降血糖活性评价

本文采用药典方法和高效液相色谱法分析了康定灵芝多糖、三萜及灵芝酸A、灵芝酸C1、灵芝酸F的含量。通过对DPPH、ABTS+自由基清除能力和总抗氧化能力的考察以及对α-淀粉酶和α-葡萄糖苷酶活性的抑制效果评价了其体外抗氧化和降血糖活性。结果显示,康定灵芝多糖和三萜含量分别为1.15%和1.50%,灵芝酸A、灵芝酸C1和灵芝酸F含量分别为0.052%、0.020%和0.064%。体外抗氧化和降血糖活性评价结果表明康定灵芝多糖提取物对DPPH和ABTS⁺自由基清除的IC₅₀值分别为0.75 mg/mL和1.24 mg/mL,对α-淀粉酶和α-葡萄糖苷酶抑制的IC₅₀值分别为1.45 mg/mL和1.97 mg/mL。三萜提取物对DPPH和ABTS⁺自由基清除的IC₅₀值分别为0.65 mg/mL和1.06 mg/mL,对α-淀粉酶和α-葡萄糖苷酶抑制的IC₅₀值分别为1.44 mg/mL和1.09 mg/mL。本文研究结果表明康定灵芝功效成分含量高,同时具有良好...     

不同蕨菜制品醇提物体外抗氧化及降血糖活性研究

目的:比较研究不同蕨菜制品醇提取物的体外抗氧化和降血糖活性。方法:分别采用Folin-Ciocalteu法、NaNO₂ -Al（NO₃）₃法测定总酚和总黄酮含量;通过DPPH法、ABTS法、普鲁士蓝法、α-葡萄糖苷酶和α-淀粉酶的抑制活性评价体外抗氧化、降血糖活性;Pearson法分析成分含量与活性的相关性。结果:不同蕨菜醇提物的总酚和总黄酮含量、抗氧化活性、α-葡萄糖苷酶和α-淀粉酶抑制活性差异显著。其中鲜品醇提取物的总酚、总黄酮含量最高,分别可达（593±3.45）mg GA/g、（156.75±1.28）mg RT/g,且鲜品醇提取物铁离子还原能力、ABTS自由基清除能力、DPPH自由基清除能力最强;湿品醇提取物对α-葡萄糖苷酶、α-淀粉酶的抑制作用最强。不同蕨菜醇提取物总酚、总黄酮的含量与其抗氧化活性均呈极显著正相关关系（P<0.01）,与降血糖活性均呈显著正相关关系（P<0.05）。结论:蕨菜鲜品抗氧化活性较强,湿品降血糖活性较强,可能活性成分为多酚类和黄酮类成分。     

攀枝花黑松露多糖的抗氧化和降血糖活性

多糖作为松露的重要成分之一,具有抗氧化,抗肿瘤和降血糖等多种生物活性。然而,多糖活性与其结构密切相关,但关于攀枝花黑松露中多糖组分的相关结构及其生物活性的研究鲜有报道。该研究采用水提法和Sephadex G-200分离纯化黑松露多糖,并对其结构及体外抗氧化、降血糖活性进行了初步分析。结果表明黑松露多糖的分子质量为1.29×104 u,主要由甘露糖、葡萄糖、鼠李糖和半乳糖组成,其摩尔比为2.89:1.81:0.34:0.50。红外光谱分析表明该组分是含有α-糖苷键的吡喃型多糖。体外抗氧化实验表明,该多糖对DPPH自由基和羟自由基均具有一定的清除作用,但对DPPH自由基表现出更好的清除能力,其IC50值为1.02 mg/mL,同时随多糖质量浓度的增加其抗氧化活性也随之升高。另外,在体外降血糖实验方面,该多糖能显著抑制α-葡萄糖苷酶和α-淀粉酶的活性,其IC50值分别为1.99 mg/mL、3.30 mg/mL。该研究结果可为深度开发黑松露多糖提供理论依据。     

黑木耳多糖体外和体内降血糖功能

目的:探讨黑木耳多糖体内和体外降血糖功能。方法:通过建立体外α-葡萄糖苷酶抑制剂微孔筛选模型,研究黑木耳多糖不同提取物及黑木耳酸性多糖不同醇沉片段对α-葡萄糖苷酶的体外抑制作用。以四氧嘧啶诱导建立糖尿病小鼠模型,通过黑木耳酸性多糖的治疗,比较治疗前后小鼠体质量及空腹血糖值的变化、测定治疗后小鼠体内糖代谢关键酶——己糖激酶和琥珀酸脱氢酶的活性,研究黑木耳酸性多糖对四氧嘧啶致糖尿病小鼠的降血糖作用。结果:体外降血糖效果表明,黑木耳多糖有抑制α-葡萄糖苷酶的作用,3种不同的黑木耳多糖样品中,黑木耳酸性多糖抑制α-葡萄糖苷酶的活性最强,黑木耳中性多糖次之,黑木耳碱性多糖最弱。黑木耳酸性多糖不同醇沉片段中,80%醇沉片段抑制α-葡萄糖苷酶的活性最强。体内降血糖效果表明,黑木耳酸性多糖80%醇沉片段可减缓糖尿病小鼠体质量的负增长,缓解己糖激酶、琥珀酸脱氢酶活性的降低。本实验结果表明,黑木耳酸性多糖具有明显的降血糖作用。     

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.