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1.
从天然食用紫卷心菜中提取紫红色素,并对提取溶剂、温度、时间及次数等工艺条件进了研究,研究结果表明该色素的溶解性、热稳定性、光稳定性在酸中的性质及在5×10-5mo1·L-1金属离子溶液中的稳定性是好的,氧化剂或还原剂对其有一定影响,产率0.5%,是值得开发的天然食用色素.  相似文献   

2.
以葡萄糖母液为原料,分别对采用氨水,碱和铵盐为催化剂生产食用焦糖色素进行了研究,研究结果表明,以氨水为催化剂,产率高达75%,反应速度快,以碱作为催化剂,产率为70%,产品质量好。  相似文献   

3.
大孔吸附树脂浓缩火龙果色素的研究   总被引:9,自引:0,他引:9  
探讨了吸附和洗脱火龙果色素的方法和条件.该色素在535nm处有最大吸收峰.S 8型大孔吸附树脂对火龙果色素具有较好的吸附能力.乙醇浓度对树脂上色素的解吸有影响,当浓度为40%时解吸效果最好.考察了不同进样速度下树脂柱的泄漏和不同的酸浓度对洗脱峰的影响,结果选择1.5mL/min的进样速度及0.2%HCl 40%乙醇溶液为洗脱剂.经吸附-洗脱循环,色素液浓缩17倍以上,回收率达93.4%,且色素浓缩液具有较好的稳定性.  相似文献   

4.
以葡萄糖母液为原料,分别对采用氨水、碱和铵盐为催化剂生产食用焦糖色素进行了研究.研究结果表明,以氨水为催化剂,产率高达75%,反应速度快,以碱作为催化剂,产率为70%,产品质量好.  相似文献   

5.
采用正交试验对伊犁红星苹果色素的最佳提取条件进行了研究,并探讨该色素的稳定性.结果表明:伊犁红苹果色素的最佳提取工艺为:料液比为1:30,乙醇浓度为90%,浸提时间3h,提取温40℃条件下色素产率最高;该色素耐高温性、耐光性好,在常用食品添加剂等条件下有较好的稳定性,可作为天然植物色素在食品、饮料等行业中使用.  相似文献   

6.
以黑枣果实为原料,用80%乙醇—H2O常温下浸泡24h,重复1次。浸泡液经浓缩、蒸干得色素胶质,再用丙酮溶解、浓缩、干燥、得黄色素粉末。该色素属水溶性色素,对光、热均稳定,氧化剂和还原剂可使吸光度减小,对Fe3+,Al3+,Zn2+等无作用。蔗糖可使色素吸光度数值有所下降,苯甲酸钠对色素的吸光度基本无影响,NaCl则具有增色作用。黑枣黄色素在460nm处有一吸收峰,在pH>7和pH<7条件下吸收光谱有较大差异  相似文献   

7.
以微孔淀粉对胭脂红色素的吸附量的大小为依据,选定制备微孔淀粉的工艺条件.实验结果表明,用酶法制备微孔淀粉的优化工艺条件是反应温度为45℃,pH值为4.0,反应时间为16h,酶用量为0.6%.在此条件下所制得的微孔淀粉对胭脂红色素的吸附量为5mg/g.  相似文献   

8.
运用RAPIDASE(R) INTENSE果胶酶以提高蓝莓果的出汁率,提高蓝莓色素的得率.通过正交试验确定了乙醇浸提法提取蓝莓色素的最佳提取条件:70%的乙醇溶液为提取剂,提取温度为30 ℃,提取时间为2 h,料液比为1:10.在此条件下,色素得率为4.8%.  相似文献   

9.
液体发酵野油菜黄单胞菌,生产大量菌液,通过离心、浓缩获得野油菜黄单胞菌色素干品,进行热、光照、酸碱度对色素稳定性的影响试验。结果表明,野油菜黄单胞菌黄色素在高温、长时间光照、强酸碱度条件下,性状稳定,吸收波长稳定在330 nm。  相似文献   

10.
通过对甘谷辣椒红色素进行提取,确定了其中的4种成分,研究了色素提取的最佳条件及色素的稳定性.结果表明:该色素含有辣椒红色素、辣椒玉红素、β-胡萝卜素、辣椒碱、二氢辣椒碱5种主要成分.色素在480 nm有最大吸收峰,该色素水溶性较差,油溶性较好,在pH值4~10时色调不变,具有良好的热稳定性.温度为90℃时,色素稳定.良好的耐酸碱性,耐光性较差,连续光照48 h,色素残存率为45%,1 mg/L Na+,Ca2+、Al3+溶液对色素最大吸收峰无明显影响,1 mg/L Cu2+,Fe2+溶液使色素最大吸收峰偏移.  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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