谷氨酰胺转移酶处理对大豆分离蛋白、酪蛋白酸钠和明胶可食膜特性的影响

研究了谷氨酰胺转移酶(TGase)对大豆分离蛋白(SPI1和SPI2)、酪蛋白酸钠(NaCN1和NaCN2)及明胶(G1和G2)3类蛋白质成膜特性的影响。研究表明在成膜溶液中加入TGase(8U/g蛋白),可以使SPI、NaCN和明胶等3类蛋白质膜的抗拉强度和表面疏水性有不同程度的改善,其中抗拉强度增加的辐度为13.1%(P≤0.05),而表面疏水性增加的辐度为2%～216%(P≤0.05);明显降低了膜的水分含量、总可溶性物量及透光率。对于断裂伸长率,TGase的处理使G1膜、NaCN2膜、G2膜、NaCN1膜和SPI2膜分别增加16.3%、16.8%、43.0%、72.6%和440.5%,而使SPI1膜降低7.5%。SDS-PAGE电泳分析表明TGase使这3类蛋白质均产生了共价交联。     

改性大豆分离蛋白对顺丁橡胶/丁苯橡胶复合材料性能的影响

将糊化改性的大豆分离蛋白( SPI)等量替代炭黑填充至顺丁橡胶/丁苯橡胶中,研究了改性SPI的粒径和热性能,考察了改性SPI用量对橡胶复合材料物理机械性能、热性能、压缩生热性能的影响,并与白炭黑和轻质碳酸钙填充复合材料进行了对比.结果表明,改性SPI的中位径由原来的115.25 μm减小至37.63 μm,比表面积由原...     

大豆分离蛋白及其接枝物水溶液性质的研究

利用接枝共聚方法得到了大豆分离蛋白(SPI)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)的接枝共聚物SPI-g-PAMPS,研究了SPI及SPI-g-PAMPS在水中的溶解性、表面疏水性、Zeta电位以及流体力学半径.结果表明SPI-g-PAMPS在等电点附近的溶解性与SPI相比有明显改善,表面疏水性随接枝率的增大而降低,在所测范围内SPI-g-PAMPS体系的Zeta电位值较纯SPI降低.在等电点附近纯SPI的流体力学半径约为800nm左右,接枝改性后减小至140nm左右.     

多重改性大豆分离蛋白可降解材料性能研究

大豆分离蛋白(SPI)经四氢呋喃、乙酸锌、顺丁烯二酸酐多重改性后,用水和甘油增塑,然后经热压制得力学性能和抗水性能良好的可生物降解材料。研究了四氢呋喃、乙酸锌、顺丁烯二酸酐用量对SPI可生物降解材料力学性能、抗水性能的影响。结果表明:当改性剂四氢呋喃、乙酸锌、顺丁烯二酸酐的用量分别为大豆分离蛋白的267%、7%和15%时,SPI可降解材料的性能最佳,其断裂伸长率、拉伸强度、吸水率和耐水指数分别为187.12%、9.29 MPa、30.9%和0.48。     

增塑剂聚乙二醇(300)对大豆分离蛋白/玻纤复合材料性能的影响

采用大豆分离蛋白和玻纤作原料,并用聚乙二醇(300)进行增塑,采用传统的热压成型方法来制备大豆分离蛋白/玻纤复合材料。加入10份聚乙二醇(300),SPI/GF复合材料拉伸强度和吸水率降低,断裂伸长率和流动性则呈明显升高。     

交联大豆蛋白-聚氨酯复合乳液的制备

首先合成了具有自乳化特性的-NCO封端的聚氨酯预聚体(NPUP),然后通过-NCO与大豆分离蛋白(SPI)分子中的-NH2在水相中反应,制备出了新型交联大豆蛋白-聚氨酯复合乳液.研究结果表明,随着NPUP制备配方中三乙胺与二羟甲基丁酸摩尔比的增加,乳液固体物含量和乳胶膜的拉伸强度逐渐升高,当三乙胺与二羟甲基丁酸摩尔比不...     

燕麦β-葡聚糖─大豆分离蛋白美拉德产物的制备及性质

为了制备燕麦β-葡聚糖(OG)和大豆分离蛋白(SPI)的美拉德反应产物(MRPs)并研究功能性质和结构，采用湿法美拉德反应，以接枝度和色度值为指标探究工艺参数对反应的影响；通过测定溶解性、乳化特性、起泡特性以及分析SDS-PAGE电泳、内源性荧光光谱和傅里叶变换红外光谱来表征SPI的功能性质和结构的变化。结果表明，反应时间为100 min、温度为85℃、pH为7.5、蛋白与多糖质量比为1:1.2是制备MRPs的最佳工艺条件。在此条件下反应后，SPI的溶解性最高达到93.97%、乳化活性和乳化稳定性最高为38.268 m²·g^-1和67.5 min，起泡能力和起泡稳定性提高到47.2%和86.8%，利用结构表征也可以表明SPI进行了糖基化。OG和SPI成功制备了MRPs并改善了功能性质。     

PLA/SPI复合纤维的电纺制备与表征

以聚乳酸（PLA）和大豆分离蛋白（SPI）为原料,采用静电纺丝技术,制备了PLA/SPI复合纤维。采用FT-IR、SEM、XRD等分析手段对复合纤维进行表征。结果表明：PLA/SPI复合纤维中PLA和SPI通过氢键缔合,纤维直径分布在100~300nm之间。     

L-精氨酸/L-赖氨酸改性大豆分离蛋白乳化性

在质量浓度为20 g/L大豆分离蛋白（SPI）中分别加入终质量浓度均为1、3 g/L的L-精氨酸（L-Arg）和L-赖氨酸（L-Lys）,以不加氨基酸、仅调节与上述溶液对应相同pH的样品为处理对照,制备水包油型（O/W）乳状液。通过物化手段及光谱技术表征SPI结构、溶液的物化性质和乳化性能以及乳状液的微观结构。结果表明,L-Arg、L-Lys可提升SPI溶液的pH,显著提高蛋白溶解度（从77.1%到最大91.3%）、降低浊度,促进蛋白分子疏水性基团折叠而降低蛋白疏水性,有效降低SPI在溶液中的粒径大小并提高蛋白带电量,降低蛋白所成乳状液的乳滴大小且提高其均匀性;改性后的SPI比对照组的乳化性和乳化稳定性分别提高了31.4%和78.9%;相比之下,L-Arg比L-Lys更能有效地改性SPI结构而获得更高的乳化性,且乳化性随着这两种氨基酸浓度增加而增强。     

硝化法制备对氨基间硝基苯磺酸的研究

以对氨基苯磺酸为起始原料 ,经过乙酰化、硝化、水解三步来制备标题物。通过正交试验找出了酰化的最佳反应条件为 :对氨基苯磺酸与乙酐的摩尔比为 1∶1.0 5 ,反应总时间为 1.5h ,反应温度为 2 5℃ ,酰化介质为酰化反应前用碳酸钠及水将对氨基苯磺酸完全溶解 ,使混合液 pH值为 5～ 6 ,反应过程中不再补加碳酸钠 ,其酰化转化率可达 99.6 % ,酰化产物的固体收率可达 96 .0 % ;硝化反应的最佳条件为 :硝化剂用 90 .2 %的硝酸 ,对乙酰氨基苯磺酸与硝化剂的摩尔比为 1∶1.0 5 ,反应温度为 10℃ ,浓硫酸与对乙酰氨基苯磺酸的摩尔比为 8.3∶1,其硝化转化率可达 96 .0 % ,硝化反应的选择性好 ,对氨基邻硝基苯磺酸的量不到 1.0 %。     

Soy protein adhesion enhanced by glutaraldehyde crosslink

Soy protein has been considered as an alternative to partly replace petroleum‐based polymers for adhesive applications. The weakness of protein‐based adhesive is poor water resistance, which limits its outdoor applications. The objective of this research was to improve the water resistance of soy protein adhesive by introducing crosslinkage between amino groups of amino acid residue. Laboratory prepared soy protein isolate (SPI) was used in this study. Glutaraldehyde at concentrations of 4, 20, 40, and 80 μM was used as the crosslinking reagent for SPI modification. Adhesive properties of soy protein modified by glutaraldehyde, as well as thermal and morphological properties, were investigated. Crosslinking‐induced protein conformation and structure changes through decrease of amino groups and adding of hydrophobic groups, subsequently affect adhesive performance of SPI. At optimum glutaraldehyde concentration (20 μM), dry, wet, and soak strengths of modified SPI increased to 31.5, 115, and 29.7%, respectively, compared with unmodified SPI. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 130–136, 2007     

Laponite and PAS costabilized ASA emulsion with high hydrolysis resistance and sizing efficiency

ASA emulsions costabilized by Laponite and polyaluminum sulfate (PAS) were prepared by homogenizing the mixture of ASA and aqueous dispersion of Laponite and PAS. The properties, sizing performance and hydrolysis resistance of the prepared ASA emulsions, were investigated in this article. The results show that the introduction of PAS significantly improves the stability, hydrolysis resistance, and sizing performance of ASA emulsions. The ASA emulsion stabilized by 0.5% of Laponite (based on total mass of emulsion) and 2% of PAS (based on the mass of Laponite) shows high hydrolysis stability and high sizing efficiency on bleached chemi‐thermomechanical pulp. At the addition level of 0.3% based on bleached chemi‐thermomechanical pulp, the sizing degree of ASA‐sized paper can be as high as 120 s. Even when the storage time of the ASA emulsion exceeds 3 h, its sizing performance is hardly changed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PAPI改性大豆蛋白复合材料的制备与性能研究

以大豆分离蛋白（SPI）和多亚甲基多苯基异氰酸酯（PAPI）为原料,制备了改性大豆蛋白,再加入聚己内酯（PCL）,经过模压成型制备了改性大豆蛋白复合材料,并对其力学性能、微观结构和热性能进行了表征。结果表明,随着PAPI的加入,材料的力学性能得到很大程度的改善,拉伸强度由9.65 MPa上升到32 MPa,冲击强度由1.36 kJ/m2提高到11.7 kJ/m2;随着PAPI的加入,大豆蛋白材料的吸水性也有明显的改善,24 h吸水率从33.89 %下降到9.77 %;红外光谱分析表明,PAPI可以与大豆分离蛋白发生反应,改变了大豆蛋白的结构,并影响其性能,使复合材料内部结构更加致密。     

阳离子型无皂苯丙乳液纸张表面施胶剂的研制

以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸二甲基氨基乙酯(DM)和丙烯酰胺(AM)等为主要原料,采用无皂乳液聚合法在丙烯腈改性淀粉分子链上接枝苯丙共聚单体,合成出一种阳离子型淀粉接枝苯丙乳液施胶剂;然后以此为基料配制纸张表面施胶液,并对文化用纸和瓦楞纸进行施胶。结果表明:在其他条件相同的前提下,各种施胶纸的施胶效果均优于原纸,并且施胶度增幅最大;文化用纸的施胶度从原来的3 s增至48 s,瓦楞纸的施胶度从原来的43 s增至154 s。     

L-精氨酸/L-赖氨酸改性大豆分离蛋白乳化性

在质量浓度为20 g/L大豆分离蛋白(SPI)中分别加入终质量浓度分别为1、3 g/L的L-精氨酸(L-Arg)和L-赖氨酸(L-Lys),以不加氨基酸、仅调节与上述溶液对应相同pH的样品为处理对照,制备水包油型(O/W)乳状液.通过物化手段及光谱技术表征SPI结构、溶液的物化性质和乳化性能以及乳状液的微观结构.结果表...     

PLA—SPP共聚物的合成及其在SPI／PLA共混中的应用

以辛酸亚锡为催化剂,合成出丙交酯-大豆多肽共聚物（PLA-SPP）,并对其进行红外及核磁共振光谱表征。研究了大豆蛋白（SPI）与聚乳酸（PLA）的共混工艺,考察了PLA-SPP共聚物对SPI/PLA共混体系的影响,发现该共聚物能有效地增加两者的相容性,当共聚物的含量为5%时,共混物的相容性明显改善;样品断面扫描电镜（SEM）照片显示,其微观结构明显变得均匀,两相分散较好。DSC结果显示,共聚物的加入增大了PLA与SPI间的作用力,并阻碍了PLA相的结晶行为。同时,加入共聚物后,共混物的耐水性也得到了明显提高。     

PVAc乳胶/改性大豆分离蛋白共混胶黏剂的制备及性能

针对大豆蛋白胶黏剂耐水性差的缺点,用尿素初步改性大豆分离蛋白（SPI）,然后与白乳胶（PVAc）共混合成了共混改性大豆分离蛋白胶黏剂。采用正交实验方法考察了大豆蛋白胶与白乳胶质量比、共混时间、交联剂质量分数、交联时间对大豆蛋白胶黏剂剪切粘接强度的影响,确定了优化配比及制备工艺条件,并在此基础上采用正交试验优化了热压参数。结果表明：大豆蛋白胶与白乳胶质量比10∶1,共混时间1h,交联剂质量分数1.0%,交联时间1.5h,热压温度120℃,热压压强1.2MPa,热压时间2min/mm,涂胶量250g/m2时,测得胶黏剂的干态剪切粘接强度为2.01MPa,按照Ⅰ类胶合板标准测得湿态剪切粘接强度为1.04MPa,并对优化配方进行了结构与性能分析。     

Functional Properties of Soy Protein Isolates Produced from Ultrasonicated Defatted Soy Flakes

This study aimed to determine the effect of pretreating defatted soy flakes with ultrasound on soy protein isolate (SPI) yield and functionality. Defatted soy flakes dispersed into water (16%, w/w) were sonicated for 30, 60 and 120 s at ultrasonic amplitudes of 21 and 84 μm_pp (peak to peak amplitude in μm), representing low and high power, respectively. The power densities were 0.30 and 2.56 W mL⁻¹, respectively. The SPI yield increased by 13 and 34%, after sonication for 120 s at low and high power, respectively. The sonication of defatted soy flakes for 120 s at the higher power level improved the SPI solubility by 34% at pH 7.0, while decreasing emulsification and foaming capacities by 12 and 26%, respectively, when compared to control SPI. Rheological behavior of the SPI was also modified with significant loss in consistency coefficient due to sonication. Some of these results could be explained by the loss of the protein native state with increased sonication time and power.     

Effect of Ionic Strength on Freeze–Thaw Stability of Glycosylated Soy Protein Emulsion

This study used Soy Protein Isolate (SPI), Soy Protein Isolate Hydrolysates (SPH) and Dextran (D) as raw materials. Covalent compounds were prepared by grafting soy protein isolate and soy protein isolate hydrolysate with dextran by water-heating method, which were SPI-D and SPH-D, respectively. The effect of ionic strength (0–500 mM) on the freeze–thaw stability of SPI, SPI-D, and SPH-D emulsions was investigated. Fourier transform infrared analysis and Fluorescence emission spectroscopy analysis indicated that the structure of the protein changed. In this study, it was found that with the increase of ionic strength, the zeta potential of the three samples presented a downward trend and the surface hydrophobicity first decreased and then increased. The addition of ions effectively improved the freeze–thaw stability of the emulsions. The particle size of the emulsions changed little after freeze–thaw cycles, and coalescence degree, creaming index, and oiling off significantly decreased. Especially when the ionic strength reached 300 mM, the degree of coalescence was 248.46%, 170.92%, and 167.77%, respectively, and the oiling off was also reduced by 68.52%, 68.25%, and 59.92%, respectively. The creaming index of the SPI emulsion was 48.49% lower than the creaming index without ions. However, when the ionic strength exceeded 300 mM, the coalescence degree, creaming index, and oiling off of the emulsions increased. Optical microstructures also found that at ionic strength of 300 mM, the oil droplets produced by the three kinds of emulsion after freeze–thaw were smaller than those without ions.