甘油二酯对可可脂类油脂结晶和巧克力起霜的影响研究进展Effects of diglycerides on crystallization of cocoa butter analogues and bloom of chocolates: a review

可可脂类油脂富含对称型单不饱和甘油三酯，通过科学调控可可脂类油脂中的甘油二酯，可优化巧克力的调温工艺，控制其起霜行为。综述了可可脂类油脂中甘油二酯的含量与种类（包括脂肪酸饱和度、链长和位置分布），探讨其对油脂结晶行为的作用规律，进而分析其对巧克力抗霜性能的影响。在适宜含量下1,3-甘油二酯可促进油脂形成巧克力需要的Ⅴ型晶体结构，而1,2-甘油二酯则倾向于使油脂形成Ⅱ～Ⅳ型晶体结构，且作用程度受脂肪酸链长的影响。然而，高含量甘油二酯无法使油脂形成Ⅴ型晶体结构。当甘油二酯含量在3%～5%时，油脂虽可形成Ⅴ型晶体结构，但需根据具体含量对结晶参数进行调整。因此，有必要通过分提、复配等技术对可可脂类油脂的甘油二酯进行调控。 Cocoa butter analogues are rich in symmetrical monounsaturated triacylglycerols. Scientific regulation of diglycerides in cocoa butter analogues contributes to optimization process of tempering and bloom control of chocolates. Contents and species (including saturation degree, chain length and distribution of fatty acids) of diglycerides in cocoa butter analogues were concluded in the present review, followed by discussing their effects on crystallization behaviors of fat matrix as well as bloom resistance of chocolates. Ⅴ crystal structure could be found in the fat matrix formulating with 1,3-diglycerides at their suitable content, whereas Ⅱ-Ⅳcrystal structures were observed in the fats containing 1,2-diglycerides, and the effect degree was impacted by chain length of their fatty acids. However, high levels of diglycerides failed to form Ⅴ crystal structure in fat matrix. Although the Ⅴ crystals structure could be found with 3%-5% content of diglycerides, which also required adjustable crystallization parameters based on different contents. Therefore, it is necessary to control diglycerides of cocoa butter analogues in making chocolates through fractionation and physical blending.