Here we investigated the effects of applied shear and temperature during the early stages of nucleation on the isothermal crystallization behavior and microstructure of cocoa butter (CB). Results showed that the composition of nucleating triacylglycerols (TAGs) as well as crystalline microstructure and polymorphism of CB were affected by mixing and temperature gradients while still in the molten state. The initial crystalline material isolated from CB after it had been subjected to shear had a similar TAG composition as native CB. However, in the absence of shear, high melting TAGs such as trisaturates (SSS) along with lower amounts of monounsaturated TAGs (SUS) were present, possibly due to fractionation. After subjecting CB to shear in its molten state, crystallization rates were faster due to the cocrystallization of different TAGs into a mixed crystal; however, the polymorphic transition into the more stable β-V form was found to be slower due to inherent complexity in TAG composition. Under static conditions, the presence of high amounts of homogeneous TAGs (SSS) was correlated to faster polymorphic transformations possibly due to a templating effect.

中文翻译：

---

剪切和冷却速率对可可脂结晶行为和结构的影响：在成核初期施加剪切

在这里，我们研究了成核初期施加的剪切力和温度对可可脂（CB）的等温结晶行为和微观结构的影响。结果表明，成核三酰基甘油（TAGs）的组成以及CB的晶体微观结构和多态性受混合和温度梯度的影响，而它们仍处于熔融状态。经受剪切后从CB分离出的初始晶体材料具有与天然CB相似的TAG组成。但是，在没有剪切力的情况下，可能由于分馏而出现了高熔点的TAG，例如三饱和酸酯（SSS）以及少量的单不饱和TAG（SUS）。使炭黑在熔融状态下剪切后，由于不同的TAG共结晶为混合晶体，结晶速度更快。然而，由于TAG组成的固有复杂性，发现多晶型转变为更稳定的β-V形式较慢。在静态条件下，可能由于模板效应，大量同质TAG（SSS）的存在与更快的多态性转化相关。