反胶束提取小麦胚芽蛋白的工艺研究

以副产品小麦胚芽为原料,用反胶束法研究了小麦胚芽蛋白的提取条件,包括前萃和后萃。前萃由琥珀酸二(2-乙基己基)酯璜酸钠(AOT)-异辛烷-氯化钾缓冲溶液组成的反胶束体系从小麦胚芽中提取蛋白;后萃先回收异辛烷,少量KCl的缓冲溶液溶解剩余的固形物,最后用丙酮沉淀得小麦胚芽蛋白。通过单因素实验,考查了AOT浓度、萃取时间、加入小麦胚芽粉量、温度、KCl浓度、缓冲溶液pH、W/O对小麦胚芽蛋白前萃率的影响以及KCI浓度、缓冲液pH、缓冲液加入量对小麦胚芽蛋白后萃率的影响。     

酶解辅助反胶束法萃取小麦胚芽蛋白前萃工艺的优化

采用由AOT(琥珀酸二(2-乙基己基)酯磺酸钠)-异辛烷-KC l缓冲液组成的反胶束体系,联合酶解技术提取脱脂小麦胚芽蛋白。探讨了反应时间、缓冲液pH、酶加量3个因素对蛋白前萃率的影响,并用响应面优化前萃工艺条件。经响应面分析得到稳定点为鞍点,采用岭嵴分析进一步优化得到最佳小麦胚芽蛋白前萃工艺条件为:反应温度40℃,反应时间1 h,缓冲液pH 9.22,酶加量0.153 AU/g。在此最佳工艺条件下,蛋白前萃率达到76.99%。     

含酶反胶束体系后萃花生蛋白工艺优化研究

该文研究了含酶反胶束体系后萃花生蛋白的过程,通过考察体系pH、KCl浓度、温度和振荡时间等因素,对花生蛋白后萃率进行研究,并采用JMP10.0软件进行定制实验设计,以花生蛋白的后萃率为响应值,建立数学模型,确定花生蛋白后萃过程的最佳工艺条件:缓冲液的pH为8.06,KCl浓度为1.53 mol/L,温度为40℃,萃取时间为120 min,在此条件下进行试验获得最佳后萃率为(78.43±0.87)%。     

酶法辅助反胶束前萃取核桃蛋白的研究

在传统利用反胶束萃取核桃粕中的蛋白质的基础上,添加辅助酶萃取,此方法综合了反胶束与酶法技术的双重特征及优势。试验通过在反胶束体系中添加酶,并调节体系单因素含水量(W0)、缓冲液p H、萃取温度、萃取时间条件下测定反胶束对蛋白前萃率的影响,通过主要因素的正交试验,优化提取参数,在酶添加量为4%、p H10、萃取温度55℃、反胶束含水量W0为18、萃取时间为100 min条件下,蛋白前萃率为83.29%。SDS-PAGE电泳图像直观地呈现出酶法辅助反胶束萃取得到的核桃蛋白亚基条带及含量都普遍较单纯反胶束萃取蛋白的高。     

反胶束法提取红芸豆蛋白的前萃工艺优化

采用二-（2-乙基已基）琥珀酸酯磺酸钠（AOT）-异辛烷-氯化钾组成的反胶束体系萃取红芸豆蛋白（RKBP）。采用电导法考察AOT浓度对AOT-异辛烷-水反胶束体系含水量和临界增溶水量的影响,确定反胶束体系稳定的AOT浓度范围。采用单因素实验分别研究了AOT浓度、缓冲液pH、KCI浓度和萃取时间等因素对RKBP前萃率的影响,通过正交实验优化前萃条件。结果表明,不同AOT浓度对应的反胶束体系的临界含水量值（Wc）基本一致,反胶束体系能够增溶的水的体积随AOT浓度的增加而明显增大,反胶束体系稳定的AOT浓度上限值为2mol／L。正交优化获得反胶束法萃取RKBP的最佳前萃条件为：AOT浓度1．25mol／L,缓冲溶液pH7．5,KCl浓度0．05mol／L,萃取时间90min。在该最优工艺条件下,RKBP前萃率达到43．57％。     

反胶束法提取花生蛋白后萃工艺的优化

以琥珀酸二(2-乙基己基)酯磺酸钠(AOT)-异辛烷-氯化钾缓冲溶液为前萃体系,对从前萃体系中提取花生蛋白的后萃工艺条件进行了研究。考察了后萃时间、后萃温度、缓冲液pH、KCl浓度对花生蛋白后萃率的影响,并在单因素试验基础上,通过正交试验确定后萃最佳工艺条件为:后萃时间50 min,后萃温度40℃,缓冲液pH9.0,KCl浓度1.0 mol/L。在此最佳工艺条件下,花生蛋白后萃率达到86.49%。     

蛋白酶对反胶束体系前萃率规律影响的研究

主要研究利用4种蛋白酶在SDS/异辛烷/正辛醇反胶束体系萃取大豆蛋白的同时,对其酶解,考查酶加入量、缓冲溶液pH、W0、萃取温度、萃取时间,乙醇浓度等六因素对蛋白前萃率的影响规律,确定碱性蛋白酶萃取蛋白的最佳工艺条件是:W0值、缓冲溶液的pH、萃取时间、乙醇浓度、酶加入量、萃取温度,分别为16.1、7.5、30 min、0.4%、5%、45℃。为今后研究蛋白质分子空间结构和分子量大小与反胶束"水池"微观结构相互关系的规律奠定基础。     

反胶束法萃取玉米胚芽蛋白及其功能性研究

研究了AOT/异辛烷反胶束法萃取玉米胚芽蛋白及玉米胚芽蛋白的加工功能性。在实验中分别考察了纤维素酶加酶量、AOT浓度、KCl浓度、缓冲液pH值、W0对玉米胚芽蛋白前萃率的影响,以及萃取时间、KCl浓度、缓冲液pH值对后萃率的影响,确定了前萃的最佳技术条件:加酶量为4 000 IU/g玉米胚芽、AOT浓度为3 g/50 mL异辛烷、萃取pH 6、KCl浓度0.1 mol/L、W0为25;后萃的最佳技术条件为:KCl浓度为0.5 mol/L、萃取pH 10.5,萃取时间40 min;对玉米胚芽蛋白的部分加工功能性进行研究,结果表明其吸油性(2.9 mL/g)、乳化性(54.5%)、乳化稳定性(86.5%)以及泡沫稳定性(58.3%)都较好,但吸水性和起泡性相对较差,玉米胚芽蛋白不但营养效价高,而且具有较好的加工功能特性,在食品工业中具有应用潜力。     

反胶束法提取辣木籽蛋白工艺优化

以脱脂辣木籽粉为原料,利用反胶束法提取辣木籽蛋白并进行工艺优化。通过单因素实验和正交实验考察反胶束（AOT）质量浓度、提取温度、pH、料液比、水分活度（Wo）5个因素对提取辣木籽蛋白的反胶束前萃工艺的影响,再通过单因素实验和二次通用旋转实验考察提取温度、pH、KCl浓度、提取时间4个因素对提取辣木籽蛋白的超声波辅助反胶束后萃工艺的影响。结果表明：反胶束前萃最佳工艺条件为pH 9、料液比1∶ 50、AOT质量浓度0.08 g/mL、提取温度45 ℃、水分活度25,该条件下所得前萃辣木籽蛋白提取率为67.2%;超声波辅助反胶束后萃最佳工艺条件为提取时间45 min、提取温度45 ℃、pH 6.5、KCl浓度1.25 mol/L,在此条件下所得后萃辣木籽蛋白提取率为58.5%。     

二次通用旋转组合设计法优化AOT反胶束体系萃取大豆蛋白质的研究

表面活性剂浓度、pH、温度、W0、电解质浓度、乙醇浓度与时间是影响AOT反胶束萃取大豆蛋白质的主要因素,采用二次通用组合旋转对AOT反胶束前萃取大豆蛋白质的工艺进行了研究,建立前萃工艺回归方程,得出前萃工艺优化条件分别为:W014、AOT浓度0.08 g/mL、pH值7.0、KCl浓度0.05 mol/L、萃取时间30 min、萃取温度40 ℃、乙醇浓度0.5%.在此条件下,蛋白质含量为24.14%,蛋白前萃率为65.82%.     

Optimization of a novel backward extraction of defatted wheat germ protein from reverse micelles

In this work, a novel backward extraction procedure of defatted wheat germ protein (DWGP) from reverse micelles was explored. Isooctane was recovered by vaporization firstly. Then the remained residue was dissolved in a small amount of KCl solution. The recovery of DWGP was easily performed by the ternary liquid system (acetone: deionized water: isooctane = 15:5:1) precipitation, while most of sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT) remained in the ternary liquid system. In the end, the precipitation of DWGP was washed with 65% ethanol solution to further remove any residual AOT. The effects of KCl concentration, the amount of KCl solution and pH on the backward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum backward extraction was achieved by response surface methodology (RSM). When the operation ran under optimized conditions, the backward extraction efficiency of DWGP achieved 80% and the end protein product was completely free of AOT.Industrial relevanceThis experimental result confirmed that this novel backward extraction method had many advantages on the extraction of protein compared to the traditional backward extraction method (changing the conditions of pH and ionic strength in a fresh aqueous phase). This method increased the backward extraction efficiency of defatted wheat germ protein (DWGP) from 57% to 80%, saved the water resource and offered the possibility of precipitating nearly pure DWGP, completely free of surfactant. On the basis of these advantages, it appears that this novel backward extraction technique may have great potential for being scaled-up to a commercially extraction process of protein.     

脱脂麦胚中谷胱甘肽与麦胚蛋白提取

对脱脂麦胚中谷胱甘肽(GSH)和麦胚蛋白的提取进行研究。首先采用低pH 值条件从脱脂麦胚中提取谷胱甘肽,并采用超滤将该提取液中的谷胱甘肽与蛋白质进行分离。再对提取过GSH 后的麦胚残渣中的蛋白质进行碱提研究。最后合并超滤分离出的蛋白质与碱提蛋白质,采用等电点沉淀法对麦胚蛋白进行纯化制备。采用单因素试验结合正交试验分别对GSH 和麦胚蛋白的提取工艺进行优化,并最终确定GSH 最佳提取工艺为提取pH6.3、提取时间15min、固液比1:13(g/mL)、提取温度55℃,GSH 的得率和提取率分别为0.31% 和72.1%。麦胚蛋白的最佳提取工艺为提取pH10.5、提取温度65℃、固液比1:11、提取时间60min。提取蛋白质相对于碱提用沉淀的得率为39.2%,提取率为90.4%。相对于总麦胚得率为20.8%,提取率为58.8%。合并超滤截留液与碱提离心上清液,确定沉淀蛋白质最佳pH4.2,蛋白质沉淀率为97.5%,所得蛋白质含量达85.2%,相对于脱脂麦胚中总蛋白质提取率为81.1%。     

反胶束对植物蛋白的结构、物化特性、功能性和应用的影响研究进展

反胶束提取法是一种适用于生物大分子分离纯化的新技术,在植物蛋白提取方面具有广阔的应用前景。本文介绍了国内外反胶束法提取和纯化植物蛋白的研究进展,阐述了反胶束体系的定义以及其提取蛋白质的原理和特点,并比较和总结了反胶束法和传统方法制备的植物蛋白结构和物化性质的差异,讨论了反胶束萃取法对植物蛋白的结构、物化、功能性和应用的影响,提出了反胶束萃取技术应用到工业生产中面临的主要难题,并根据提取特点展望其应用前景。     

AOT反胶束体系萃取大豆蛋白质的研究

研究了AOT反胶束萃取大豆蛋白的工艺,针对影响AOT反胶束萃取大豆蛋白质的各种因素如反胶束直径、缓冲溶液pH值、离子强度、温度、萃取时间进行了研究,得出主要的影响因素为反胶束直径、缓冲溶液pH值和离子强度,并得到最佳的萃取条件为:反胶束直径为4.9nm,此时的Wo值为15.8;pH值为6.5;离子强度为0.1mol/L;萃取温度为45℃;萃取时间为20min。在此条件下蛋白质的萃取率为82.57%。     

Stabilization effect of zeolite on DHFR mRNA in a wheat germ cell-free protein synthesis system

The effects of zeolites and monocations on the protein synthesis in a cell-free system derived from wheat germ were investigated. M type of synthetic zeolite markedly enhanced the translation efficiency. Whereas this kind of stimulatory effect of zeolite in an Escherichia coli cell-free system resulted from a change in the salt compositions of the reaction solution with the addition of zeolite, the enhancement of protein synthesis in a wheat germ cell-free system was not due to the ion exchange reaction of zeolites. From the results of mRNA stability analysis, it was found that zeolite could stabilize the mRNA in a wheat germ cell-free protein synthesis system. The stabilization of mRNA by the simple addition of zeolites is useful for the enhancement of protein synthesis in a wheat germ cell-free system, since conventional methods to improve mRNA stability, such as the addition of nuclease inhibitor, have not been effective for a wheat germ cell-free system.     

Refolding of cytochrome c using reversed micelles

A novel protein refolding method using reversed micelles has been developed, which could replace the conventional dilution method using a buffer solution. The novel refolding method enables efficient refolding at a high protein concentration. In the present study, denatured bovine heart cytochrome c was directly solubilized in AOT reversed micelles using the solid-liquid extraction technique. Results reveal that addition of urea in small amounts facilitates solubilization of denatured protein into the reversed micellar phase. Reversed micelles containing a high concentration of denatured cytochrome c could be easily prepared by the novel solubilization method. The nanostructural environment formed by the surfactant molecules in organic media is considered to promote the renaturation of denatured proteins because the protein molecules are isolated from each other through the solubilization step. Although the recovery of entrapping proteins from the reversed micellar phase was known to be difficult in a conventional reversed micellar extraction operation, the addition of alcohol to the recovery phase improved the efficiency of back extraction. Therefore, we succeeded in recovering renatured cytochrome c from the reversed micelles. We demonstrated that the novel protein refolding method is very useful for the renaturation of denatured proteins.     

微波法辅助反胶束技术前萃取大豆蛋白工艺

以全脂大豆为研究对象,为提高反胶束前萃取大豆蛋白的效率,利用变频微波萃取仪,辅助反胶束技术前萃取大豆蛋白。研究单因素即提取温度、pH值、液料比与时间对大豆蛋白提取率的影响,通过主要因素的响应面试验,优化提取参数,且检测了参数之间相互作用关系。利用统计分析和优化,结果显示,微波对前萃取大豆蛋白影响的相对大小依次为提取时间＞温度＞pH值。结果表明：在提取温度43.3 ℃、pH 8、萃取时间23 min时,蛋白质前萃率达到最高水平,提取率80.61%。