首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 609 毫秒
1.
采用蛋白酶、果胶酶、纤维素酶复合处理冬瓜多糖溶液,通过对复合酶的作用温度、作用pH值、作用时间进行单因素实验,对复合酶配比、复合酶的提取工艺进行正交试验,确定了复合酶法提取冬瓜多糖的最佳工艺条件:复合酶按纤维素酶1.5%,果胶酶1.5%,蛋白酶1.5%配比,酶作用温度40℃,酶作用pH值为5.0,酶作用时间为40 min,多糖提取率最高.  相似文献   

2.
研究了纤维素酶和果胶酶在假酸浆提取物制取黄酮苷元过程的酶解工艺.依次对纤维素酶、果胶酶及复合酶进行了去糖基化修饰研究.结果表明,复合酶去糖基化作用相较于两酶单独作用效果更佳,其最佳工艺条件为:pH值为假酸浆提取物的自然pH值,酶解温度为40℃,含酶量为纤维素酶和果胶酶各0.5%,酶解时间4 h,还原糖浓度显著提高.  相似文献   

3.
酶法提取金针菇多糖   总被引:11,自引:0,他引:11  
余冬生  王文高 《应用科技》2001,28(10):56-57,52
研究了金针菇多糖提取的最佳工艺条件。单因素实验确定了纤维素酶,菠萝蛋白酶提取的最佳工艺条件,在此基础上进行了复合酶正交实验的研究,结果得出最佳工艺条件是时间80min,温度50℃,pH值4.0,纤维素酶1.0%,菠萝蛋白酶1.0%,果胶酶1.0%。  相似文献   

4.
酶辅助提取对薯蓣皂甙产率的影响   总被引:1,自引:0,他引:1  
研究了酶对薯蓣皂甙提取率的影响,试验结果表明,采用复合酶(纤维素酶、果胶酶、α-淀粉酶)的效果要比单一酶的效果好.  相似文献   

5.
确定了复合酶(纤维素酶、果胶酶、中性蛋白酶)提取蕨麻多糖的最佳工艺,并对其体外抗氧化活性进行初步研究.在单因素试验的基础上,设计L9 (33)正交实验和L9(34)正交实验,分别得出复合酶的最佳配比和复合酶法提取蕨麻多糖的最佳提取工艺条件;采用清除·OH(羟基)自由基模型和O2-·(超氧阴离子)自由基模型评价了蕨麻多糖的抗氧化能力.结果表明:复合酶的最佳配比为:纤维素酶2.0%,木瓜蛋白酶1.0%,果胶酶2.0%;最佳工艺条件为∶料液比为1∶30、pH值为4.5,温度为45℃,酶解时间为60min,此时蕨麻多糖的提取率最大为8.12%,同时验证性实验也表明优化得到的提取工艺稳定可靠;蕨麻多糖对羟基自由基和超氧阴离子都具有较强的清除作用,并与浓度呈一定依赖关系,且对羟自由基的清除能力要比超氧阴离子自由基的清除能力强.  相似文献   

6.
以西藏林芝茶树老叶为材料,采用复合酶有机溶剂法提取茶叶中茶多酚.在单因素实验的基础上,应用响应曲面法进一步优化提工艺,得到最佳提取条件:纤维素酶用量6 mg,果胶酶用量8 mg,溶剂体积分数68%,料液质量浓度0.024 g/mL,提取温度56 ℃,提取时间129 min,pH=5.0,茶多酚提取率为15.61%.  相似文献   

7.
采用正交试验,以野菊花中黄酮得率为指标,对表面活性剂SDS强化超声波-复合酶法中影响黄酮提取效果的主要因素进行研究。结果表明:酶解最佳提取条件是纤维素酶和果胶酶添加配比为3∶1,添加量为0.04g,酶解温度为30℃,在此基础上提取黄酮得率为8.86%;在复合酶优化结果基础上,进一步进行表面活性剂SDS强化超声处理,SDS强化超声处理的最佳提取条件是料液比1∶50、超声波提取时间65min、SDS溶液质量浓度为0.5%,酶解时间为60min,黄酮得率为13.78%。与其他提取方法相比,SDS强化超声波-复合酶法节能高效。  相似文献   

8.
利用以纤维素酶为主体包含果胶酶的复合酶系处理花生水剂法制油过程中碾磨后的油料,能显著提高花生油收率及花生蛋白得率.经优化实验得出酶处理的最适参数为:加酶量0.3%.酶反应时间4h,pH6.4,温度49℃.  相似文献   

9.
本文研究了由碱性蛋白酶、淀粉酶、碱性纤维素酶复配而成的复合酶在合成洗衣粉中的应用.结果表明:洗衣粉中添加复合酶,大大提高了其去污力,可同时去除各种类型污垢;在适宜条件下,复合酶与洗衣粉中各成分配伍性良好,并具有较高的酶活稳定性.  相似文献   

10.
蔗渣是蔗糖加工废弃物,微生物利用蔗渣水解物作为碳源进行发酵可生产乙醇、乳酸等能源物质和化工原料,具有重要应用价值.采用微波加热结合酸碱处理工艺破坏蔗渣致密结构并去除木质素,比较4种商品纤维素酶对经预处理的蔗渣的酶解效果.最后针对蔗渣的复杂结构采用了复合酶酶解工艺.结果表明将蔗渣按1∶50固液比,在微波功率为280 w下加热,先于1%NaOH处理10 min,然后再于1%H2SO4处理5 min可有效破坏蔗渣的致密结构,去除部分木质素.采用的4种商品纤维素酶中,Yacult R-10纤维素酶酶解效果最好,最佳酶解条件为添加4 000 U/g预处理蔗渣,pH5.5,温度50℃,酶解时间12 h.采用复合酶组合(纤维素酶,果胶酶,木聚糖酶和半纤维素酶12∶2∶3∶5)酶解蔗渣得到酶解液总葡萄糖质量浓度为5.99 g/L.  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.
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   

18.
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   

19.
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   

20.
<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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号