Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada; email:
Annu Rev Food Sci Technol. 2021 Mar 25;12:567-590. doi: 10.1146/annurev-food-070620-022551. Epub 2021 Jan 19.
Cocoa butter displays complex crystallization behavior and six crystal polymorphic forms. Although the crystal structure of cocoa butter has been studied extensively, the molecular interactions between cocoa butter triacylglycerols in relation to polymorphic transformations from metastable forms (forms III and IV) to stable crystal forms (forms V and VI) remain largely unknown. In this review, the triclinic polymorphism and melting profiles of the major triacylglycerols in cocoa butter-POP, POS, and SOS-are reviewed, and their binary and ternary phase behaviors in metastable (pseudoβ') and stable (β) crystal forms are discussed. We also attempt to clarify how the transformation of cocoa butter from form IV to V, as a critical step in the tempering of chocolate, is controlled by POS interactions with both POP and SOS. Moreover, we show how the crystal forms V and VI of cocoa butter are templated by crystal forms β and β of POS, respectively.
可可脂表现出复杂的结晶行为和六种晶型。尽管可可脂的晶体结构已经得到了广泛的研究，但可可脂三酰基甘油之间的分子相互作用与从亚稳定形式（形式 III 和 IV）向稳定晶体形式（形式 V 和 VI）的多晶型转变之间的关系在很大程度上仍然未知。在这篇综述中，我们回顾了可可脂-POP、POS 和 SOS 中主要三酰基甘油的单斜晶型和熔融曲线，并讨论了它们在亚稳定（假β'）和稳定（β）晶体形式中的二元和三元相行为。我们还试图阐明可可脂从形式 IV 向形式 V 的转变，作为巧克力调温过程中的关键步骤，是如何受到 POS 与 POP 和 SOS 的相互作用控制的。此外，我们展示了可可脂的晶体形式 V 和 VI 是如何分别由 POS 的晶体形式 β 和 β 模板化的。
