Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria C1428EGA, Buenos Aires, Argentina.
J Sci Food Agric. 2011 Nov;91(14):2551-7. doi: 10.1002/jsfa.4425. Epub 2011 May 2.
Cyclodextrins (CDs) are able to enhance the solubility, stability and bioavailability of several bioactive hydrophobic compounds by complex formation. They can also be used for removal of undesired components (such as cholesterol, off-flavors or bitter components) present in foods. Although many patents account for the use of cyclodextrins for removal of cholesterol from dairy foods, there is no available information on the effect of water on encapsulation efficiency and on the stability of sterols in CDs. The aim of this work was to study the inclusion properties and the factors affecting the encapsulation and stability of cholesterol in β-cyclodextrin (BCD). The optimum encapsulation conditions (ligand-CD molar ratio, stirring time and temperature), and stability of the complexes as a function of storage time and water content were analyzed.
Phase solubility study pointed out the formation of 1:1 stoichiometric complexes between cholesterol and β-cyclodextrin, which was influenced by temperature variations. The process was shown to be exothermic and energetically favored. The presence of cholesterol greatly modified the BCD water sorption curves, being the amount of adsorbed water smaller in the combined systems. The principal 'driving force' for complex formation is the substitution of the high-enthalpy water molecules by an appropriate hydrophobic ligand. The freeze-dried complexes probed to be stable at different storage conditions.
The phase solubility and stability data obtained could be essential for selecting the most suitable conditions when CDs are employed either for removing cholesterol or to incorporate functional ingredients (i.e. sitosterol) in the development of innovative food products.
环糊精（CDs）能够通过形成配合物来提高几种疏水性生物活性化合物的溶解度、稳定性和生物利用度。它们还可用于去除食品中存在的不良成分（如胆固醇、异味或苦味成分）。尽管许多专利都提到了使用环糊精从乳制品中去除胆固醇，但关于水对包封效率的影响以及甾醇在 CD 中的稳定性的信息尚不可用。本工作旨在研究β-环糊精（BCD）中胆固醇的包封特性和影响因素。分析了最佳包封条件（配体-CD 摩尔比、搅拌时间和温度）以及复合物随储存时间和含水量的稳定性。
相溶解度研究指出，胆固醇与β-环糊精之间形成了 1:1 的化学计量配合物，这受到温度变化的影响。该过程是放热的，从能量角度是有利的。胆固醇的存在极大地改变了 BCD 的水分吸附曲线，在组合体系中吸附的水量较小。形成配合物的主要“驱动力”是用适当的疏水分子取代高焓水分子。冷冻干燥的复合物在不同的储存条件下被证明是稳定的。
所得的相溶解度和稳定性数据对于选择最适合的条件非常重要，无论是在使用 CDs 去除胆固醇还是在开发创新食品产品时掺入功能性成分（如甾醇）时。
