【作者】 李延科；

【导师】 杨锦宗； 张淑芬；

【作者基本信息】 大连理工大学 ， 应用化学， 2004， 博士

【摘要】 在碱性催化剂存在下，以蔗糖、硬脂酸酯(AS)为原料，采用甲醇法、低皂无溶剂法及中皂无溶剂微乳法合成了一系列单酯含量不同的硬脂酸蔗糖酯。考察了酯糖比、反应温度、催化剂量、皂量、反应残压等因素对硬脂酸酯转化率、蔗糖酯产率及产品中单酯、二酯和多酯组成的影响，在此基础上，对三种合成方法的优劣进行评估，并最终确定中皂无溶剂微乳合成法为最佳合成方法。用该无溶剂微乳法还合成了不同单酯含量的棕榈酸蔗糖酯、月桂酸蔗糖酯和油酸蔗糖酯。此外，用HPLC-ELSD对反应过程中体系单酯、二酯和多酯的变化进行了跟踪研究，对反应过程中各糖酯成分的变化原因进行了初步的探讨。 采用TLC、HPLC-ELSD、ESI-MS、HPLC-MS等技术对硬脂酸蔗糖酯、棕榈酸蔗糖酯及月桂酸蔗糖酯的组成进行了定性和定量分析。用不同的展开剂及TLC扫描仪对蔗糖酯反应过程中及产品中的脂肪酸酯、脂肪酸和脂肪酸皂、蔗糖酯成分进行了分离及定量分析。采用高效液相色谱及蒸发光散射检测器对硬脂酸蔗糖酯、棕榈酸蔗糖酯及月桂酸蔗糖酯产品中的蔗糖单酯、二酯、多酯及糖等成分进行了分离。以纯棕榈酸蔗糖酯的液相色谱峰作基准，对硬脂酸蔗糖酯和棕榈酸蔗糖酯产品中的棕榈酸单酯、二酯和多酯以及硬脂酸单酯、二酯和多酯的峰进行了归属和定量分析。利用电喷雾质谱对所有硬脂酸蔗糖酯、棕榈酸蔗糖酯及月桂酸蔗糖酯的组成进行了定性分析。利用HPLC-MS及EIC技术对蔗糖酯产品进行了分析。 研究了硬脂酸蔗糖酯、月桂酸蔗糖酯、棕榈酸蔗糖酯的结构组成与表面张力、界面张力的关系。通过简化Hanson’s三维模型，提出了两维溶解度参数模型，根据不同蔗糖单酯、二酯和三酯在水和溶剂中的溶解性能及相应的溶解度参数对它们进行了分区。根据每一种蔗糖酯所处的区及它所对应的相互作用半径的不同，对蔗糖酯的界面现象进行了分析和解释。 研究了硬脂酸蔗糖酯、月桂酸蔗糖酯、棕榈酸蔗糖酯的结构组成与发泡力、硬水稳定性、乳化力等性能的关系。研究了蔗糖酯与阴离子和非离子表面活性剂的复配性能及不同单酯含量、不同脂肪酸链长及不同浓度的蔗糖酯对荔枝的保鲜效果。更多还原

【Abstract】 Sucrose stearates with the different proportion of monoesters were prepared by reacting sucrose and alkyl searate (AS) in the presence of alkali catalyst by "methanol process", "low soap solvent-free process" and " medium soap solvent-free microemulsion process". The influences of molar ratio of AS to sucrose, reaction temperature, the amount of catalyst and soap, and residual pressure etc. on the conversion of AS, the yield of sucrose esters and the proportion of mono-, di-and polyesters were investigated. On the basis of comparison of superiority of these three processes, the medium soap solvent-free microemulsion process was opted as the final process for producing sucrose esters. Sucrose palmitates, sucrose laurates and sucrose oleates were also prepared form the solvent-free process. In addition, changes in the proportion of mono-, di- and polyesters in reaction process were monitored by HPLC-ELSD.Some analytical techniques, such as TLC, HPLC-ELSD, ESI-MS, HPLC-MS, were applied for the analysis of sucrose stearates, sucrose palmitates and sucrose laurates. The qualitative and quantitative results of the sucrose esters, soap, fatty acid, sucrose and fatty acid ester in crude and purified products were obtained by using TLC and TLC scanner and different separate agents. HPLC-ELSD was also used for the separation of sucrose monoesters, diesters and polyesters. Pure sucrose palmitates were prepared and used for the identification of mono-, di- and polypalmitates in sucrose stearates and sucrose palmitate. Commercial and synthesized sucrose esters containing mono-, di-, tri- or higher esters were qualitatively analyzed using electrospray ionization-mass spectrometry (ESI-MS). Sucrose esters were also analyzed by high-performance liquid chromatography (HPLC) in combination with electrospray ionization mass spectrometric detection in positive ion mode.Relationships of the composition and structure of sucrose esters to interfacial properties were investigated. A two-dimensional model of solubility parameters was established by simplifying the Hansen’s three-dimensional model. The model comprises three areas corresponding to solubility parameter and solubility of different sucrose esters. According to the interaction R, interfacial phenomena of different sucrose monoesters, diesters, triesters and some commercial sucrose esters and synthesized sucrose esters at oil-water interface can be interpreted logically.Some physiochemical properties of sucrose esters, such as foamability and form stability, stability in hard water and emulsifying power were investigated. The synergism of sucrose esters with other surfactants and effect of sucrose ester coating on storage life and quality of litchi was evaluated.更多还原