化学改性大豆蛋白凝胶溶胀过程规律的研究  

SWELLING BEHAVIOR OF CHEMICAL MODIFIED SOY PROTEIN GELS

作　　者：王飞镝[1] 柯晴瑾[1] 王凌伟[1] 奚红霞[2] 崔英德[3] 

机构地区：[1]广东工业大学轻工化工学院,广州510006 [2]华南理工大学化工与能源学院,广州510640 [3]仲恺农业工程学院化学与化工系,广州510225

出　　处：《高分子学报》2010年第9期1116-1121,共6页Acta Polymerica Sinica

基　　金：广东省绿色化学产品技术重点实验室研究基金(基金号GC200702)资助项目

摘　　要：将大豆蛋白(SPI)经预热处理、EDTAD酰化和戊二醛交联,制备出改性大豆蛋白凝胶.通过红外与化学法研究了改性大豆蛋白分子的结构变化,结果表明,经EDTAD改性,大豆蛋白分子的侧链基团和分子链构象均发生变化;侧链的游离氨基与EDTAD发生酰化反应,为蛋白质分子链引入羧基;基团分析数据显示,改性大豆蛋白分子中游离氨基数减少,羧基数增加,增加的羧基数与减少的氨基数之比约为3:1.研究了改性大豆蛋白凝胶的溶胀率变化,并对溶胀数据进行数学处理,分析了不同mEDTAD:mSPI的凝胶的溶胀过程规律,结果显示,mEDTAD:mSPI为0,0.05,0.1和0.2的改性大豆蛋白凝胶在水中的溶胀率为24.2,54.01,87.27和95.87,说明分子链引入一定量的EDTAD使凝胶溶胀率增大;其溶胀特征指数为0.5,表现为Fickian扩散.研究了改性凝胶在不同pH下的溶胀过程规律,结果显示,在pH4.30和6.08时,凝胶溶胀特征指数n范围是0.5<n<1,表现为non-Fickian扩散,而在碱性pH10.04,凝胶特征溶胀指数为0.5,仍表现为Fickian扩散.改性大豆蛋白凝胶溶胀率对pH变化具有敏感性,其溶胀-消溶过程曲线呈"W"形,显示凝胶具形状记忆功能.A chemically modified soy protein gel was prepared by first preheating and then acylating the soy protein with ethylenediaminetetraacetic dianhydride（EDTAD）,followed by crosslinking with glutaraldehyde.The variation of molecular structure of modified soy protein and the variation of swelling ratio of gels were investigated;moreover,the swelling behavior of modified soy protein gels at different mEDTAD：mSPI and different pH was analyzed by treating the swelling data with mathematical method.The results showed that the free amimo groups of soy protein side chain reacted with EDTAD,which incorporated carboxyl groups into soy protein molecule chain;the ratio of the amount of added carboxyl group and lost amino group was about 3：1 in soy protein molecules.The swelling ratio of soy protein-based gels was 24.2,54.07,87.27 and 95.87 when mEDTAD：mSPI was 0,0.05,0.1 and 0.2,respectively,which showed that increasing the amount of EDTAD incoporating into the protein molecular chain resulted in the increasing of swelling ratio of gels.The swelling characteristic exponent（n） of the above gels was about 0.5,which meant that the protein-based gels appeared Fickian＇s diffusion behavior in water,the same behavior appeared to the modified soy protein gels at pH 10.04;but at pH 4.30 and pH 6.08,the range of n was 0.5 〈n 〈1,which meant a non-Fickian＇s diffusion behavior.The mechanism of swelling behavior of gels was discussed.The swelling ratio of gels appeared pH-sensitivity,the＂W＂— shaped curve of swelling — deswelling process appeared,which meant the function of＂shape memory＂of gels.

关 键 词：化学改性 凝胶 蛋白质 溶胀过程 

分 类 号：TQ936.2[化学工程]