纺织品pH值测定用萃取介质的优化

在保障纺织品p H值测定结果较好重现性和再现性的同时,为解决纺织品p H值测定引起的含盐废水处理难度大的问题,本研究对萃取介质进行优化,采用易通过纳滤技术脱除盐分的Na2SO4、K2SO4等二价强酸强碱盐溶液,取代三级水和KCl溶液（0.1mol/L）,作为萃取介质进行纺织品p H值测定,并将测定结果与采用三级水或KCl溶液（0.1mol/L）为萃取介质的结果进行对比分析。结果显示,以浓度为0.067 mol/L的Na2SO4或K2SO4溶液为萃取介质,测定得到的纺织品p H值结果,与以KCl溶液（0.1mol/L）为萃取介质得到的测试结果相近,再现性和重现性也均优于以三级水为萃取介质得到的测试结果。     

萃取因素对pH值测定结果的影响

为了更好地实施GB／T7573,对比了新旧标准中差异,并对不同萃取液（三级水或0．1mol／L的KCl溶液）、不同pH值的三级水、振荡速率和振荡时间对纺织品pH值测试结果的影响进行了试验。试验结果表明：采用三级水和0．1mol／L的KCl溶液作为萃取液测得的pH值的差值较大,且对不同样品的影响不同;三级水本身的pH值会影响样品pH值的测试结果;而某些试样的pH值会随着振荡速率的增加而增大;萃取1h的试样pH值与萃取2h的试样的pH值存在一定的偏差。     

纺织品pH值测试方法探讨

将纺织品分成偏酸性、接近中性和偏碱性3大类,先以符合标准要求的水为萃取介质在国标、日标和美标下测试,然后在国标下采用0.1 mol/L的氯化钾(KCl)溶液为萃取介质进行测试,结果表明:国标测试值最小,日标略大,美标最大;且随着纺织品pH值增加,3个标准间的测试差值呈增大趋势;在国标下测试,偏酸性纺织品采用符合标准要求的水为萃取介质即可,接近中性和偏碱性纺织品应以KCl溶液为萃取介质,且氯化钾溶液作为萃取介质在测试耗时上有优势;在实际测试中还应注意标准和要求范围的差异所导致的检测不合格现象。     

不同pH值的萃取介质对纺织品pH值检测结果的影响

为了研究不同pH值的萃取介质(三级水和0.1mol/L的氯化钾水溶液)对纺织品pH值检测结果的影响,采用6种不同pH值的三级水及其0.1mol/L的氯化钾水溶液,对28个面料进行pH值测定.试验结果显示:萃取介质的pH值对纺织品pH值的测定结果存在着较大的影响,用pH值差值为1.9的三级水进行测试的结果差异在0.4～2...     

GB/T 7573—2009《纺织品水萃取液pH值的测定》新标准解读

介绍了新标准在技术内容上的调整,通过大量的试验数据分析了试验用水、萃取介质、萃取时间、样品调湿等因素对纺织品水萃取液pH值测定的影响。证明采用0.1mol/L的KCl溶液作为萃取介质,萃取时间(60±5)min,可以得到满意的数据。     

纺织品pH值检测的稳定性

介绍了影响纺织品pH值测定的几个因素,如萃取介质、萃取时间和振荡方式等,并分析了其对测试结果稳定性的影响。试验表明,以0.1 mol/L KCl为萃取介质,旋转式（或往复式）振荡萃取（60±5） min,可以快速稳定地测定出纺织品的pH值,提高了工作效率。     

萃取介质和萃取时间对纺织品pH值测定的影响

为了研究不同萃取液（三级水和0．1mol／L氯化钾溶液）、萃取时间和缓冲溶液调谐对纺织品pH值测定的影响,对14个样品进行了对比分析和讨论,试验结果表明：萃取介质和不同缓冲液调谐对pH值测定结果的影响较大,而萃取时间对pH值测定结果的影响相对较小。     

纺织品pH值测试的影响因素探讨

测试了pH计、萃取介质、取样部位、萃取液静置时间及振荡速率因素对纺织品pH值测试结果的影响。试验结果表明,除振荡速率外,pH计、萃取介质、取样部位及萃取液静置时间因素对pH值测试结果均有较大的影响。建议测试纺织品pH值时,选用实验室通用型号的pH计,以0.1mol/L氯化钾溶液作为萃取介质,并严格遵循取样规范,以确保测试结果的稳定性。     

尼龙涤纶类纺织品坯布pH值检测方法探讨

本文对GB/T7573-2009中规定的使用水及KCl萃取液作为萃取介质对尼龙涤纶类纺织品进行pH值测量,对不同类的纺织品pH值检测差异的因素进行探讨。结果表明:纺织品坯布上的浆料是导致纺织品在使用GB/T7573-2009方法时,不同介质萃取液pH值存在差异的主要因素。     

pH值测定中不同萃取介质的影响分析

分析了依据GB/T7573—2009进行pH值测定时,不同的萃取介质对测试结果的影响,提出了国标pH值测定存在的问题:未指定唯一萃取介质及其限量值,并根据国外标准的规定,提出解决方法,建议规定pH值测定采用氯化钾溶液为萃取介质,更能与国际标准接轨,减少资源浪费。     

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%。      

GB/T 7573-2009中萃取介质对纺织品pH值测定的影响

根据GB/T 7573-2009《纺织品水萃取液pH值的测定》,研究了采用去离子水与氯化钾作为萃取介质所测得的纺织品pH值是否存在差异,以及该差异对最终判定结果的影响。结果表明弱酸性、强碱性样品经两种不同萃取介质处理后pH值相差不大,中性及弱碱性样品经两种不同萃取液处理后pH值差异较明显。     

Interactions between soy protein isolate and xanthan in heat-induced gels: The effect of salt addition

The influence of xanthan and/or KCl addition on the properties of heat-induced soy protein isolate (SPI) gels at pH 3.0 was studied. Changes in protein solubility and subunit composition as well as in the mechanical properties, microstructure and water holding capacity of the gels were determined. The effect of KCl addition on each biopolymer solution was also investigated. The results indicated that SPI–xanthan gels prepared without KCl were mainly stabilized by non-covalent (H-bonding and hydrophobic) and SS bond interactions, whereas in gels containing KCl, electrostatic interactions were also involved in maintaining the gel structure. The β-7S subunit was probably the fraction electrostatically linked to the xanthan. The different values found for the mechanical properties after the addition of xanthan and/or KCl, were associated with the coarseness of the gel. Xanthan and KCl probably showed a synergistic effect on the Young modulus because KCl induced a conformation transition of the xanthan molecules.     

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%。     

Production of soy protein isolates with low phytic acid content by membrane technologies: Impact of the extraction and ultrafiltration/diafiltration conditions

The content of the antinutrient, phytic acid, of soy protein was analyzed during their extraction and purification by a series of ultrafiltration and diafiltration steps. The phosphorus content of the extracts was used as an indication of their phytic acid content and their ash content as an indication of their mineral content. The extraction of soy proteins was conducted by using a 2³ factorial experimental design, pH (7.5 or 9), solvent (0.06 M KCl or water), and temperature (25 °C or 50 °C). The most promising extraction conditions were 0.06 M KCl/pH 9.0/25 °C for the lowest phosphorus to protein ratio (12.2 ± 0.1 mg P/g protein) and H₂O/pH 9.0/50 °C for the combination of low phosphorus to protein ratio and the lowest ash content (13.9 ± 1.2 mg P/g protein, 9.6 ± 0.8% w/w ash content). After extraction, soy proteins were purified by sequential ultrafiltration (UF) with a volume concentration ratio (VCR) of 5 and diafiltration (DF) with volume diafiltration ratio (VD) of 4. Extracts were purified with no pH adjustment or with pH adjustment to 6.5 between the UF and the DF steps. The extraction conditions 0.06 M KCl/pH 9.0/25 °C and the purification conditions UF pH 9.0/DF pH 6.5 showed the lowest phosphorus to protein ratio (4.4 ± 0.3 mg P/g protein) and reduced membrane fouling when compared to extraction conditions with water.     

超声波辅助SDS反胶束前萃花生蛋白研究

采用SDS(十二烷基磺酸钠)/异辛烷―正辛醇反胶束体系萃取花生蛋白,并采用超声波辅助萃取,主要研究全脂花生粉加入量、缓冲溶液pH值、萃取时间、萃取温度、超声波功率、KCl浓度、SDS浓度、Wo对蛋白萃取率影响。设计正交实验优化萃取工艺,结果表明,最优前萃工艺条件为:花生粉加入量0.015 g/mL、缓冲溶液pH值9、萃取时间40 min、萃取温度35℃、超声波功率270 W、KCl浓度0.25 mol/L、SDS浓度0.07 g/mL、Wo为24;在此条件下,花生蛋白萃取率为89.62%±1.15%。     

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.     

超声波辅助反胶束提取菜籽蛋白后萃研究

探索一种超声波辅助反胶束法提取菜籽蛋白的后萃方法,即先回收异辛烷,然后用少量KCl 缓冲溶液溶解剩余固形物,再添加适量乙醇,最后利用菜籽蛋白进入水相而分离得到。运用Uniform Design(均匀设计)对各因素的最佳水平范围进行研究,通过SPSS 软件对回归方程的分析得最佳后萃率时各因素的最优组合为酒精2ml,钾离子浓度1.2mol/L,缓冲液25ml、pH9.5,在此工艺条件下,菜籽蛋白的后萃率为59.56%。     

双水相技术在萃取橙皮苷中的应用

研究双水相萃取橙皮苷的成相体系及影响萃取率的因素。通过试验研究选择丙酮与(NH4)2SO4-H2O 为双水相体系,研究盐用量、pH 值及粗提物的用量对萃取率的影响。结果表明：在90% 丙酮与(NH4)2SO4 溶液体积各为10ml 的情况下,(NH4)2SO4 用量4.0g、样品0.35g、pH4 的条件下,萃取效率最佳。经萃取,橘皮中的橙皮苷主要进入有机相中,萃取率为98.22%。通过薄层分析,在365nm 紫外灯下,上相溶液与标准品的斑点Rf 值接近,下相溶液检测不到橙皮苷。