两种反胶束体系对大豆蛋白前萃的比较研究

主要研究了以SDS/异辛烷/正辛醇反胶束体系萃取大豆蛋白的前萃过程,并分析了各因素对蛋白前萃率的影响,与AOT/异辛烷反胶束体系萃取大豆蛋白进行比较,SDS/异辛烷/正辛醇反胶束体系提取大豆蛋白的前萃率高于AOT/异辛烷反胶束体系。SDS/异辛烷/正辛醇反胶束体系萃取低温脱溶豆粕中蛋白质的最佳前萃工艺条件为:SDS浓度0.08 g/mL,加料量0.1000 g,反胶束溶液中含水量18,萃取时间30 m in,萃取温度40℃,增溶水pH 7,KC l浓度0.1 mol/L。     

不同反胶束体系萃取大豆蛋白研究

利用AOT/异辛烷/KCl溶液,SDS/异辛烷―正辛醇/KCL溶液,CTAB/异辛烷―正辛醇/KCL溶液三种反胶束体系前萃取大豆蛋白质,针对影响大豆蛋白萃取率的各种因素如W0、缓冲溶液pH、萃取温度、萃取时间、离子强度进行了研究,得到了三种反胶束前萃取的最佳工艺:W0均取16;缓冲溶液pH分别为6.5、6.5、10;萃取温度分别为45、45、35℃;萃取时间均取30 min;离子强度均取0.05 mol/L。试验结果表明AOT和SDS反胶束最佳前萃取条件相同,CTAB反胶束最佳前萃条件中pH和萃取温度与以上两种体系不同,其它条件相同。     

反胶束溶液萃取大豆蛋白前萃工艺的研究

本文研究了AOT/异辛烷反胶束溶液萃取大豆蛋白的前萃机理和工艺,研究了pH、 W0、表面活性剂AOT的浓度、KCl的浓度、萃取时间和萃取温度对蛋白前萃取率的影响,得到了以AOT/异辛烷体系萃取低温脱脂豆粕中蛋白质的最佳前萃工艺条件。     

SDS/异辛烷(正辛醇)反胶束体系萃取植物蛋白的研究

利用十二烷基磺酸钠(SDs)/异辛烷(正辛醇)反胶束体系萃取植物蛋白.主要研究SDS/异辛烷(正辛醇)反胶束体系萃取棉籽粕和大豆蛋白的萃取,分析各种因素对蛋白萃取率的影响.主要讨论含水量Wo对萃取丰的影响及物料的性质对反胶束萃取植物蛋白的影响.并与AOT/异辛烷反胶束体系萃取棉籽粕和大豆蛋白的萃取率作了比 较.结果表明:SDS/异辛烷(正辛醇)反胶束体系萃取大豆时的萃取率较高.     

反胶束溶液萃取杏仁蛋白前萃工艺的研究

对AOT/异辛烷反胶束溶液萃取杏仁蛋白的前萃工艺进行了研究。试验以AOT/异辛烷为反胶束溶液体系,以蛋白质萃取率为指标,分别对溶液的pH值、W0值、萃取时间和萃取温度进行了单因素试验以及四因素三水平的正交试验,以确定杏仁蛋白前萃的最佳工艺。正交试验结果方差分析表明,在各因素中,W0值对蛋白质提取率影响达到显著水平,其他三因素未达到显著水平,确定的最佳工艺条件为:W0值为40,溶液pH值7.0,前萃温度25℃,前萃时间90 min。     

反胶束萃取大豆蛋白的功能性研究

主要研究了AOT/异辛烷反胶束溶液萃取的蛋白与碱溶酸沉法生产的大豆蛋白产品功能性的差异,并对这两种大豆蛋白进行了电泳分析,得出其组分的不同。     

物料与体系性质对反胶束前萃取蛋白的影响

研究了物料与体系性质对AOT/异辛烷反胶束体系前萃取蛋白的影响。考察了原料粒度、加入方式、预处理、加span - 6 0对萃取率的影响。按 10 0目大豆粉 0 4 g用 0 1mol/LKCl配成溶液直接加入 2 0mL 0 0 8g/mL的反胶束溶液 ,180r/min ,2h。此时蛋白一次萃取率在 4 9 0 %左右 ,经纤维素酶处理后萃取率为 5 8 6 %。反胶束萃取蛋白的过程很快能达到平衡。     

超声波辅助AOT反胶束体系后萃大豆蛋白的研究

研究超声波辅助反胶束体系(AOT/异辛烷)萃取大豆蛋白的后萃过程,并分析各因素对蛋白后萃率的影响,通过正交试验得到了AOT/异辛烷反胶束体系萃取全脂大豆粉中蛋白的最佳后萃工艺条件为:KCl浓度1.0 mol/L、pH值7.0、超声功率为270 W.在此条件下,蛋白质的后萃率为98.91%.     

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％。     

反胶束萃取技术制备大豆蛋白组分的电泳法研究

对不同条件下丁二酸二异辛酯磺酸钠(AOT)/异辛烷反胶束溶液萃取的大豆蛋白进行电泳分析,同时考察反胶束萃取与碱溶酸沉法生产大豆蛋白产品组分的差异.蛋白产品组分分析表明,随着反胶团"水池"半径的减小,反胶束能萃取较大的大豆蛋白质亚基的比例有明显的减小;大豆分离蛋白与反胶束萃取的大豆蛋白所含的亚基比例有明显的差别.     

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。     

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。     

混合反胶团提取α-淀粉酶

以十六烷基三甲基溴化铵(CTAB)和脱水山梨醇单硬脂酸酯聚氧乙烯醚(Tween-60)为混合表面活性剂溶于正丁醇-异辛烷中构成反胶团系统,萃取纯化α-淀粉酶。研究不同萃取条件下,α-淀粉酶的萃取率。其中反胶团相组成为：ρ(CTAB+Tween-60)＝4g/L;n(CTAB):n(Tween-60)＝2.0:1.0;V(正丁醇):V(异辛烷)＝1.0:1.0。水相组成为：α-淀粉酶配制的粗酶液,此时c(NaCl)＝0.04mol/L,水相pH11.04。结果表明：萃取温度40℃、V(有机相):V(水相) ＝2.0:1.0、振荡时间10min时,α-淀粉酶萃取率可达91%;反萃取水相组成为c(NaCl)＝2.5mol/L、pH4.5、V(水相):V(有机相)＝1.0:2.0,反萃取振荡时间10min、温度50℃时,α-淀粉酶反萃取率可达65%。反胶团相可重复使用,当V(水相):V(有机相)＝1.0:2.75时,反胶团第2次α-淀粉酶萃取率达到71%。     

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%。     

Effects of extraction temperature,ionic strength and contact time on efficiency of bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micellar backward extraction of soy protein and isoflavones from soy flour

BACKGROUND: Soy protein enriched with isoflavones has been linked to various disease‐preventing and health‐promoting activities owing to the antihypertensive, hypocholesterolaemic, antiobesity and antioxidative properties of isoflavones. The isoflavone profiles of soy‐based products are known to be highly dependent on the various chemical and physical treatments to which the products have been subjected. The aim of this research was to increase the efficiency of backward extraction of soy protein and isoflavones from bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles by studying the effects of extraction temperature, ionic strength of the aqueous stripping solution and contact time on the amounts of soy protein and isoflavones backward extracted from an AOT/H₂O/isooctane reverse micellar system. RESULTS: By modifying the extraction temperature, ionic strength and contact time, 47.0–60.2% of protein, 43.3–68.4% of daidzin, 43.8–74.6% of genistin, 39.0–88.8% of glycitin, 20.8–92.6% of malonyl genistin, 20.2–52.0% of malonyl glycitin, 32.7–75.6% of acetyl genistin, 49.7–76.8% of daidzein and 19.6–38.1% of genistein present in the AOT reverse micellar solution were backward extracted into the aqueous stripping phase. Statistical analysis showed that there were significant linear and interactive effects of temperature and contact time on the backward extraction of daidzin, genistin, glycitin and daidzein. Significant linear and interactive effects of ionic strength and contact time were found in the backward extraction of daidzin and genistin. The backward extraction of genistein was only influenced by contact time and its interaction with temperature. CONCLUSION: This study showed the potential of reverse micelles as a protocol for extracting isoflavones from soy samples for analytical purposes. By modifying the extraction temperature, contact time and ionic strength, soy protein enriched with daidzin, genistin, daidzein and genistein could be produced from soy flour. The results represent an important contribution to current knowledge on utilising reverse micellar extraction in food technology. Copyright © 2007 Society of Chemical Industry     

反胶束体系及其萃取大豆蛋白应用的研究

本文主要研究了几种不同反胶束体系的配制,分别测定了体系中的Wo,并进行了比较分析得出阴离子表面活性剂加溶水量比较大。用几种Wo相对比较大的反胶束体系萃取了低温脱溶豆粕中的蛋白,比较前萃率得出SDS/异辛烷/正辛醇反胶束体系对大豆蛋白的前萃率较高。     

Process development for a novel milk protein concentrate with whey proteins as fibrils

Milk protein concentrate (MPC) is a preferred ingredient to provide nutritional and functional benefits in various dairy and food products. Altering the protein configuration and protein-protein interactions in MPC can provide a novel functionality and may open doors for new applications. The fibrilization process converts the globular structure of whey proteins to fibrils and consequently increases viscosity and water holding capacity compared with the native protein structure. The objective of the current work was to selectively convert the whey proteins in MPC as fibrils. For this purpose, simulated control model MPC was prepared by combining solutions of micellar casein concentrate (MCC) and milk whey protein isolate (mWPI) to give casein and whey protein in an 80:20 ratio. The mWPI solution was converted to fibrils by heating at low pH, neutralized, and combined with MCC solution similar to control model MPC and termed “fibrillated model MPC.” Thioflavin T fluorescence value, transmission electron microscopy, and gel electrophoresis confirmed the fibril formation and their survival after neutralization and mixing with MCC. Further, the fibrillated mWPI showed significantly higher viscosity and consistency coefficient than nonfibrillated mWPI. Similarly, fibrillated model MPC showed significantly higher viscosity and consistency coefficient compared with control model MPC. Hence, the fibrillated model MPC can be used as ingredient to increase viscosity. Heat coagulation time was found to be significantly higher for control model MPC compared with fibrillated model MPC.     

Functional and conformational characterisation of walnut protein obtained through AOT reverse micelles

Walnut protein was extracted from defatted walnut flour by bis (2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micellar system and alkali solution with isoelectric precipitation. The functional and conformational characteristics of two proteins were investigated and compared. Walnut protein obtained through AOT reverse micelles was found to have higher extraction yield, solubility, emulsifying activity, foam capacities, water‐ and oil‐holding capacity compared to the protein from alkali solution along with isoelectric precipitation, while the surface hydrophobicity (H₀), contents of disulphide bond (SS) and sulfhydryl group (SH) were relatively lower. The differences of H₀, SS and SH contents could be due to the conformational changes of walnut proteins using two extraction methods. FTIR spectra and data showed that the reverse micelles caused the decrease in α‐helix, β‐sheet, random and β‐turn of walnut protein, the increase in the side‐chain structure content, which could be responsible for the modification of functional properties.     

Gemini型阳离子表面活性剂反胶束体系萃取纤维素酶的研究

本文研究了Gemini型阳离子酯季铵盐表面活性剂Ⅱ-14-3反胶束萃取纤维素酶的性能,以探索新型表面活性剂在反胶束萃取酶蛋白中的应用。考察了水相pH、离子强度、离子种类、酶浓度、表面活性剂浓度、助溶剂浓度、溶剂比和助表面活性剂(卵磷脂)等因素对萃取率的影响,确定了萃取纤维素酶的最佳条件:[NaCl]=50mmol/L,[Ⅱ-14-3]=0.3mmol/L,pH6.4,C0=0.14,溶剂比S=1.0,萃取率E接近80%,其酶活达到原来的93.38%;若加入适量的卵磷脂([Ⅱ-14-3]/[PC]=36:1)可提高萃取率,萃取率E达90%以上,且酶活达到121.41%。并且从反胶束微观结构给予解释。