(1.College of Food Sciences and Engineering, South China University of Technology, Guangzhou 510640, China;2.Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou 510640, China;3.Dongguan University of Technology, Dongguan 523808, China)
The existence of granular crystals seriously impairs the quality of plastic fats, and consequently, it is important to investigate the formation mechanisms and inhibitions of granular crystals in order to optimize the processing parameters and improve the product properties. The migration and aggregation of high-melting triglycerides as well as β polymorphism evolution are the possible mechanisms for the formation of granular crystals when temperature fluctuates. The fats composition and processing parameters have influences on the granular crystals formation such as shearing rates, temperature, cooling rates. To prevent their generation, modifying lipids by blending and interesterification and the application of emulsifiers were adopted to reduce the content of the high-melting triglycerides and stabilize the β′ polymorphism. Emulsifiers are mainly associated with the triglycerides present in the fat through acyl-acyl interactions, thus the chemical structures' similarity between the acyl groups would likely promote the cocrystallization, while the dissimilarities in fats structure might delay the nucleation and possibly inhibit crystal growth. Emulsifiers have different effects on the crystallization of plastic fats which strongly depend on their concentration and the molecular structure. In addition, when the degree of undercooling is high enough, addictive effects of emulsifiers will be weakened.
LI Lin, WAN Liting, LI Bing. Review on Formation Mechanisms of Granular Crystals in Plastic Fats and Its Control[J]. Journal of Food Science and Technology,2016,34(2):1-11.Copy