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1.
微波辅助提取米糠多糖的工艺   总被引:3,自引:0,他引:3  
以脱脂挤压米糠为原料,采用微波辅助法提取米糠多糖,并与传统热水浸提方法进行比较,通过考察料液比、微波辐射时间以及微波功率三个因素,设计正交试验,得出微波辅助提取米糠多糖的优化工艺条件为:料液比1:10,微波辐射时间为2min,微波炉功率400W.传统热水浸提米糠多糖提取率为2.02%,纯度为68.53%,微波辅助提取多糖的提取率为2.76%,纯度为72.47%.与传统热水浸提方法相比较,微波辅助法的米糠多糖提取率和纯度分别提高了36.6%和5.7%.微波辅助法提取可以显著提高米糠多糖的提取效率,但对其理化性质并无影响.  相似文献   

2.
微波法水提取沙棘叶中黄酮的研究   总被引:3,自引:0,他引:3  
以水为介质,对沙棘叶进行微波处理提取黄酮,其提取效果与常规水浸提法比较表明,微波提取效率大大提高.微波水提取黄酮的最佳工艺条件为:微波功率360W,提取时间3min,沙棘叶粉与水的质量比为1:30,提取率为1.21%.  相似文献   

3.
桑叶多糖的提取工艺研究   总被引:4,自引:0,他引:4  
研究了水浸提法提取桑叶多糖的工艺条件,比较了超声法、酶法和微波法等不同的前处理方法对桑叶多糖提取效率的影响.结果表明:(1)水浸提法提取桑叶多糖的较优方案为:温度80℃、时间1h、料液比1:40,桑叶多糖的得率约为11.50%.(2)超声法辅助提取桑叶多糖的较优方案为:超声功率300W,超声处理10min,之后水浸提多糖的得率为12.25%.(3)纤维素酶为桑叶多糖的最佳酶提取剂,其酶解的较优方案为:酶用量为桑叶量的1.5%,酶解时间2h,酶解温度50℃,酶处理后水提多糖得率为12.49%.(4)微波辐射时间以8min为宜,微波法辅助提取多糖得率为11.68%.(5)比较4种处理方法提取桑叶多糖的得率,依次为:酶辅助法〉超声辅助法〉微波辅助法〉水浸提法,综合考虑成本、工作效率等因素,以超声法前处理、水浸提桑叶多糖得率较高.  相似文献   

4.
微波技术提取油菜花粉多糖工艺的研究   总被引:2,自引:0,他引:2  
以超临界CO2萃取脂肪酸后的油菜花粉为原料,研究微波技术提取油菜花粉多糖的工艺.本文考察了浸提固液比、微波强度、微波处理时间对多糖提取率的影响,并用正交法设计得出最佳工艺条件:浸提固液比为1:30,微波强度高档,微波处理时间10min.  相似文献   

5.
樊素芳  徐翠莲  王彩霞  赵士举 《河南科学》2009,27(11):1373-1376
以红枣为原料,对微波辅助法提取红枣多糖的工艺条件参数进行了研究,通过正交试验确定了红枣多糖的最佳提取工艺条件:料液比(g:mL)=1:20,温度80℃,微波提取时间1h,红枣多糖提取率最高可达3.1%.同时,将提取出来的红枣粗多糖用2%的盐酸水解后,直接与氨基酸进行美拉德反应,制备出棕色的具有芝麻酱香味的反应型香料物质.研究了反应温度、反应时间、pH值以及氨基酸和多糖的质量比等条件对制备出来的香味物质的影响,得出其最佳反应条件为:反应温度110℃,pH值8.5,反应时间2.5h,多糖与氨基酸的质量比=1:2.在该条件下制备出来的香味物质产量高、香气浓郁.  相似文献   

6.
以茶果冬青为原料,经微波破壁,水作溶剂回流提取黄酮类化合物,并用2SI-106A型大孔吸附树脂分离纯化,研究了含水量、微波处理时间、处理次数及溶剂种类等因素对提取率的影响.结果表明,实验的最佳条件为:含水量20%,微波处理3次,每次30S,料液比1:6和1:4各回流提取1h;经2SI-106A型大孔吸附树脂吸附,50%乙醇洗脱,提取率为96.3%,精制后产品收率为4.38%,总黄酮含量25.7%.  相似文献   

7.
以葡萄籽为材料,采用单因素和正交实验优化葡萄籽黄酮和多糖的微波辅助分步提取工艺。结果表明:黄酮提取的最佳条件:70%乙醇,料液比1:10(g/m L),微波功率100 W处理60 s,黄酮得率为57.73 mg/g;将提取黄酮后自然晾干的葡萄籽渣按料液比1:25(g/m L)加入水,微波功率150 W处理40 s,多糖得率为52.47 mg/g。优化后的微波辅助分步提取葡萄籽黄酮和多糖的方法,操作简单、快速、高效,提高了葡萄籽的附加值。  相似文献   

8.
运用微波技术提取莱菔子总黄酮和多糖,用比色法测定总黄酮和多糖含量。结果表明:莱菔子中总黄酮含量为0.60%,平均回收率为100.3%,RSD=1.04%(n=5)。多糖含量为12.73%,平均回收率为101.54%.RSD:0.46%(n=5)。运用微波技术从莱菔子中联合提取总黄酮和多糖,其反应速度加快,提取效率提高。  相似文献   

9.
微波辅助提取黄芪多糖的工艺研究   总被引:31,自引:1,他引:30  
以水为提取剂,研究了微波辅助提取黄芪多糖的工艺,得到了微波辅助提取黄芪多糖的最佳工艺条件:液料质量比为12:1;用饱和石灰水调节pH=9;微波功率300W时提取2次,每次提取10min.提取液真空浓缩后,加入乙醇使多糖沉淀,过滤,沉淀用乙醇洗涤多次,真空干燥后即得黄芪粗多糖,产率为14.6%,纯度为88.1%.与直接加热提取法相比,微波辅助提取能缩短提取时间,降低提取剂用量,并能提高黄芪多糖产率。  相似文献   

10.
采用正交试验方法,确立了微波法提取水杉黄酮的提取工艺条件。结果表明,最优提取条件为乙醇浓度80%,提取时间5min,固液比1:20g/mL,此时黄酮得率为1.601%  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  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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