The gelation process of mixtures of γ-oryzanol and sitosterol structurants in sunflower oil was studied using light scattering, rheology, and micro-scanning calorimetry (Micro-DSC). The relation between temperature and the critical aggregation concentration (CAC) of tubule formation of γ-oryzanol and sitosterol was determined using these techniques. The temperature dependence of the CAC was used to estimate the binding energy and enthalpic and entropic contribution to the tubular formation process. The binding energy calculated at the corresponding temperatures and CACs were relatively low, in order of 2 RT (4.5 kJ mol⁻¹), which is in accord with the reversibility of the tubular formation process. The formation of the tubules was associated with negative (exothermic) enthalpy change (ΔH ⁰ ) compared with positive entropy term (−T ΔS ⁰ >0), indicating that the aggregation into tubules is an enthalpy-driven process. The oryzanol–sitosterol ratio affected the aggregation process; solutions with ratio of (60 oryzanol–40 sitosterol) started aggregation at higher temperature compared with other ratios.

中文翻译：

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浓度和温度对食用油有机凝胶中γ-谷维素+β-谷甾醇小管形成的影响。


利用光散射、流变学和微扫描量热法 (Micro-DSC) 研究了葵花籽油中 γ-谷维素和谷甾醇结构剂混合物的凝胶化过程。使用这些技术确定了温度与γ-谷维素和谷甾醇的小管形成的临界聚集浓度(CAC)之间的关系。 CAC 的温度依赖性用于估计管状形成过程的结合能以及焓和熵的贡献。在相应温度和CAC下计算的结合能相对较低，约为2 RT (4.5 kJ mol ^-1 )，这与管状形成过程的可逆性一致。与正熵项（−T Δ S ⁰ >0）相比，小管的形成与负（放热）焓变（Δ H ⁰ ）相关，表明聚集成小管是一个焓驱动的过程。谷维素与谷甾醇的比例影响聚集过程；与其他比例相比，（60 谷维素–40 谷甾醇）比例的溶液在更高的温度下开始聚集。