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1.
《河南科学》2016,(7):1097-1100
以桔梗多糖为研究对象,采用单因素及正交实验对微波辅助热水浸提桔梗多糖工艺进行了研究,分析了料液比、温度、提取时间、微波功率、粒度、微波时间等因素对多糖提取率的影响.实验结果表明传统热水提取法的最佳工艺条件:浸提温度80℃,提取时间240 min,粒度80目,料液比1∶20;微波辅助热水浸提桔梗多糖的最佳工艺条件:料液比1∶20,微波处理时间2 min,微波功率400 W,热水浸提温度80℃,粒度80目,热水浸提时间240 min.采取短时高频微波前处理利于多糖析出,再通过后续热水浸提,其多糖提取率为32.85%,高于传统热水浸提(16.59%)和微波提取(22.83%).  相似文献   

2.
采用正交试验法研究迎春花多糖的提取工艺,考察了浸提温度、浸提时间、浸提次数、液料比4个因素对迎春花多糖提取率的影响.确立了迎春花多糖最佳提取条件为:液料比40:1,浸提温度为70℃,回流提取3次,提取时间为每次40min.  相似文献   

3.
荔枝多糖的提取条件及含量测定   总被引:19,自引:1,他引:18  
采用料水比、浸提温度、浸提时间3因素3水平的正交试验法优化了荔枝多糖的提取条件,并用硫酸-苯酚法对荔枝多糖含量进行了测定.结果表明,荔枝多糖最佳提取条件为:料水比为1:9,浸提温度为100℃,浸提时间为4h;荔枝多糖换算因子为1.45,多糖平均质量分数为4.36%,多糖含量测定相对标准偏差(RSD)为1.57%.  相似文献   

4.
采用能有效保护抗病毒活性基团的直接水提法提取异枝麒麟菜活性硫酸多糖,通过正交试验研究了影响多糖得率的工艺参数:KCl质量分数、温度、时间、料液比;通过均匀试验研究了其中影响最大的因素的最佳水平.结果表明,温度和KCl质量分数为多糖得率的最大影响因素,其最佳水平分别为125℃和0.93%.结合实际情况,最佳提取工艺条件可为:浸提温度95~100℃、浸提时间6h、料液质量比1:90、KCl质量分数0.93%.  相似文献   

5.
考察了水提法提取满天星水溶性多糖的工艺条件和体外抗氧化活性.采用L9(3^4)正交试验方法,研究了料液比、浸提温度、浸提时间、提取次数对提取效率的影响.在选定的工艺条件下,料液比和提取温度对满天星水溶性多糖提取率的影响大于提取时间、提取次数的,料液比和提取温度为主要影响因素;最佳工艺条件为料液比1:20、提取温度80℃、提取时间1.5h、提取次数三次.在最佳工艺条件下测得满天星粗多糖提取率为1.83%.体外抗氧化活性试验表明,满天星水溶性多糖能有效地清除DP—PH自由基,当满天星多糖浓度在0.30mg/mL以上时,对DPPH自由基的清除率超过81%.  相似文献   

6.
葎草叶蛋白提取工艺的优化   总被引:9,自引:0,他引:9  
对配合使用酸法、碱法以及加热法提取葎草叶蛋白的工艺及工艺条件进行了初步的研究,以提高其蛋白质含量。分别进行了浸提剂pH值、料液比、打浆时间、浸提时间、汁液pH值和絮凝温度对蛋白质影响的单因素实验研究,结果表明,葎草叶蛋白的最佳提取工艺条件:常温下料液比1:5,打浆时间3min,浸提时间3min,浸提剂的pH值为6~8;葎草叶蛋白的分离条件为70℃时,沉淀分离得到叶绿体叶蛋白,调pH值为10时分离出细胞质叶蛋白Ⅰ,调pH值为2时分离出细胞质叶蛋白Ⅱ;葎草叶蛋白产品在60—80℃条件下干燥。采用此工艺提取葎草叶蛋白的得率为4.62%。  相似文献   

7.
超声波法从茶叶中提取苯多酚   总被引:15,自引:0,他引:15  
介绍以陈年绿茶为原料,用超声波法提取茶多酚,并以常温浸提做比较,分别改变提取剂的浓度、体积、酸度、提取时间及料液比对产品提取率的影响进行了探讨。结果表明超声波提取茶多酚的最佳工艺条件为:70%乙醇作浸提剂,pH值为1~2,当浸提时间40min及料液比为1:10。两次超声辐射浸提后提取率为89.29/6,该法与常规溶剂提取法相比,具有提取温度低,产品得率高,氧化损耗小等特点。  相似文献   

8.
微波强化提取大枣多糖的研究   总被引:4,自引:0,他引:4  
通过正交试验确定了微波法强化提取大枣多糖的实验条件,并与常规的水浴提取法作了比较。结果表明,工艺条件为浸泡时间60min、pH6.5,微波处理5min,多糖浸提率为5.26%。与传统溶剂提取法相比,采用溶剂浸泡与微波提取集成技术提取大枣中的多糖具有明显的提取效果。  相似文献   

9.
从柑桔皮中连续提取色素、果胶的工艺研究   总被引:4,自引:0,他引:4  
实验研究了以柑桔皮为原料,用乙醇浸提色素,酸水解乙醇沉淀法提取果胶方法。最佳条件:pH1.5,温度80℃,时间2h。果胶得率13.88%。  相似文献   

10.
葛根总黄酮提取工艺条件的研究   总被引:5,自引:0,他引:5  
通过正交试验,研究了影响葛根中黄酮类物质提取的4因素,即:乙醇浓度、温度、pH、浸提时间。结果表明:用pH为8,浓度在90%以上的乙醇溶液,在80℃下浸提2h,即可提得93%的葛根总黄酮物质。  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.
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   

14.
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   

15.
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   

16.
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   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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