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1.
低聚原花青素对草莓色素的抗氧化活性研究   总被引:3,自引:2,他引:3  
草莓红色素属花色苷类化合物,在酸性条件下相对稳定,光、热对色素具有一定的降解作用.本文采用60%的乙醇溶液从葡萄籽中提取出天然抗氧化剂低聚原花青素,研究了它对草莓色素的抗氧化活性.结果表明,低聚原花青素能抑制草莓色素的氧化降解,具有明显的护色作用,同时还可起到防腐效果.  相似文献   

2.
对山西地区种植的3种葡萄(玫瑰香、维多利亚、巨峰)葡萄籽进行原花青素提取,并对所得原花青素进行抗氧化活性和稳定性的研究。结果表明,3种葡萄籽原花青素均具有一定的抗氧化效果,其中巨峰葡萄籽原花青素的自由基清除作用较好;避光、微偏酸环境和避免金属阳离子的螯合作用可有效提高葡萄籽原花青素的存放效果。  相似文献   

3.
采用Schaal耐热实验法,以过氧化值(POV)为指标,研究温度、时间对猕猴桃籽油自氧化过程的影响以及不同抗氧化剂对猕猴桃籽油抗氧化性能的影响.结果表明:温度、时间对猕猴桃籽油的自氧化过程有显著影响,温度的影响更明显;TBHQ对猕猴桃籽油具有良好的抗氧化效果,抗坏血酸和柠檬酸均对TBHQ与PG复配而成的复合抗氧化剂表现出较强的抗氧化协同增效作用,且抗坏血酸的抗氧化协同增效作用优于柠檬酸;添加0.015% TBHQ+0.005% PG+0.01%柠檬酸或0.015% TBHQ+0.005%PG+0.01%抗坏血酸复配而成的复合抗氧化剂,可使猕猴桃籽油在20℃条件下的预期贮藏时间从2个月延长至13~14个月.  相似文献   

4.
以原花青素微胶囊作为抗氧化剂,采用Schaal烘箱法对花生油进行抗氧化研究,并与合成抗氧化剂BHT、PG进行对照,同时考察了BHT、PG以及不同增效剂对原花青素微胶囊抗氧化效果的影响.结果表明,原花青素微胶囊最适添加量为0.04%;原花青素微胶囊与维生素C的增效作用最强;原花青素微胶囊与PG混合使用的效果优于与BHT混合使用的效果.并对花生油货架寿命进行了预测,可知添加抗氧化剂后,花生油的货架期均得到了不同程度的延长.  相似文献   

5.
为研究高粱红色素的体外抗氧化活性,测定了高粱红色素对1,1-二苯基-2-苦苯肼自由基(DPPH·)、超氧自由基(O2-·)和羟自由基(·OH)的清除能力,还原力,对Fe2+诱导的脂质过氧化反应和β-胡萝卜素/亚油酸自氧化体系的抑制作用.结果表明,高粱红色素对DPPH·有较好的清除能力,能很好地清除O2-·和·OH,对Fe2+诱导的脂质过氧化有一定的抑制作用,对β-胡萝卜素/亚油酸自氧化体系有明显的抑制作用,可见高粱红色素具有良好的抗氧化能力,除作为色素使用外,也可作为抗氧化剂使用.  相似文献   

6.
共选取5种黔产清热类中草药射干、头花蓼、板蓝根、龙胆草、栀子,测定了其水提取液和乙醇提取液对自由基.OH和DPPH.的清除能力,并采用IC50对其抗氧化能力进行评价。本实验还以烘箱试验来研究这些中草药抗菜籽油和猪油氧化的作用。结果表明,这5种清热类中草药对.OH和DPPH.均具有一定抗氧化作用,并且能很好地抑制菜籽油和猪油氧化。但龙胆草对猪油有一定的促氧化作用。  相似文献   

7.
目的 用超声波辅助法优化提取洛神花中花青素的提取工艺,并通过斑马鱼胚胎氧化应激模型进行抗氧化活性研究。方法 正交法进行提取工艺优化,斑马鱼胚胎进行氧化应激干预测试抗氧化水平。结果 洛神花花青素最佳提取工艺条件:提取温度30℃、超声功率300 W、料液比1∶40(g/mL)、超声时间90 min,此时得率为2.94 mg/g。体外抗氧化活性表明,5.8 mg/mL洛神花花青素对DPPH自由基清除率、ABTS自由基清除率和羟自由基清除率分别为83.15%、 63.32%和74.4%。通过斑马鱼胚胎氧化应激模型进行抗氧化活性研究发现,洛神花花青素能够有效保护由AAPH诱导的斑马鱼胚胎氧化损伤,11.6μg/mL剂量组的洛神花花青素极显著降低斑马鱼胚胎ROS的产生,抑制脂质过氧化物的生成和降低胚胎细胞死亡率,其作用效果与2.9μg/mL VC组相近。结论 超声辅助正交优化后的工艺能提高洛神花花青素得率,比单因素最高得率提高37%;良好的体内外抗氧化活性为进一步开发洛神花提供理论基础。  相似文献   

8.
杜仲黄酮的提取及抗氧化活性研究   总被引:11,自引:1,他引:10  
采用正交试验法研究了杜仲黄酮的最佳提取工艺条件,以猪油为底物,采用碘-硫代硫酸钠滴定法测定了杜仲黄酮对猪油的抗氧化活性及与有机酸的协同效应.结果表明:杜仲黄酮的最佳提取工艺条件为用质量分数为70%乙醇、料液比(g∶mL)为1∶10、80℃条件下提取3次、每次回流2 0h.杜仲黄酮对猪油具有明显的抗氧化活性,部分有机酸对其具有一定的增效作用,添加质量分数为0 30%杜仲黄酮可使猪油在20℃下的货架寿命由2 5个月延长至8 1个月.  相似文献   

9.
太子参提取物体外抗氧化活性研究   总被引:12,自引:0,他引:12  
通过清除自由基、抗脂质过氧化活力测定,对太子参提取物体外抗氧化活性进行研究.结果表明,太子参水提取物、醇提取物、皂甙粗提物清除DPPH的IC_(50)值分别为6.13、3.61和2.89 mg/L,清除羟自由基的活力分别为70.9、77.3和871.8 U/mg,清除超氧阴离子自由基的活力分别为0.55、1.93和7.71 U/mg.对亚油酸氧化的抑制率分别为0.5%、24.2%和26.9%,对H_2O_2诱导血细胞溶解的抑制率分别为22.4%、33.2%、45.6%.太子参提取物具有明显抗氧化活性,皂甙粗提物活性优于水提取物和醇提取物.  相似文献   

10.
栗壳提取物抗氧化活性研究   总被引:2,自引:0,他引:2  
以水为溶剂从栗壳中提取得到栗壳提取物CSE.以猪油和芝麻油作为底物,采用烘箱贮藏法测定油脂的POV值,研究CSE对油脂的抗氧化活性.以Fenton反应为产生·OH模型、邻苯三酚自氧化反应为产生O2-·模型,用紫外和可见分光光度法试验了CSE对模型中产生的·OH和O2-·的清除作用.结果表明:CSE具有一定的抗油脂氧化能力;CSE具有良好的清除·OH作用,且清除作用与浓度呈正相关性,EC50为80.3 mg·L-1;CSE对O2-·没有显著的清除作用.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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