摘要
利用紫外光谱法测定了β-环糊精及其衍生物(β-CDs)与柠檬草精油及其主要成分柠檬醛的包结比和包结常数,测定包结过程在20～50℃范围内的热力学参数ΔG、ΔH和ΔS。实验表明,β-CDs与柠檬草挥发油的包结比均为1:1,包结能力顺序为HP-β-CD>MD-β-CD>β-CD。从热力学角度探讨了影响包合过程的因素,包结反应是一个放热过程,包结过程的热力学参数ΔG、ΔS和ΔH均为负值,由此说明包结过程是自发进行的放热过程,包结的驱动力主要来自范德华力与疏水作用的相互作用。
The association constant and inclusion proportion for the inclusion complex of volatile oil of Cymbopogon citratus （VOC） with cyclodextrins （β-CD, DM-β-CD, and HP-β-CD） were determined in the range of 20 -50 ℃ by ultraviolet spectrometry. The effect of temperature on K value and other parameters ΔG, ΔH and ΔS had also been discussed. Good linear relationships indicated that the structures of the inclusion complex were 1：1. The association constant （Ka） of the complexes had been obtained, and the order that the capability associated with VOC was HP-β-CD DM-β-CD β-CD. The inclusive process was an exthermic and enthalpy-driven process accompanied with a negative entropic contribution, and the reciprocity of hydrophobic interaction and van der Waals force plays an importance role in the process.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2009年第23期96-100,共5页
Food Science
基金
天津市自然科学基金项目(043604511)
关键词
柠檬草精油
环糊精
紫外光谱
包结常数
热力学
Cymbopogon citratus volatile oil
β-cyclodextrin derivatives
ultraviolet spectrometry
association constants
thermodynamics
作者简介
杨欣（1983-），女，硕士研究生，研究方向为食品添加剂。E-mail：yangxin4022@126．com
通讯作者：姜了涛（1956-），男，教授，博士，研究方向为食品添加剂。E—mail：ztjiang@yahoo．com
