Triacylglyceride crystallization in vegetable oils Chapter uri icon

abstract

  • The phase changes of triacylglycerides (TAGS) are physical properties that determine the solid fat content in vegetable oils. In turn, the functional properties provided by oils and fats to a food system are established mainly by the proportion of TAGS in the solid phase and its dependence on temperature. Hydrogenation and interesterification of vegetable oils are used to modify the solid/liquid ratio of native vegetable oils. In addition to these chemical processes, TAGS crystallization is an alternative method to modify the solid/liquid ratio of vegetable oils and achieve the appropriate functionality in food systems. An overview of the events involved in TAGS crystallization in vegetable oils systems investigated in this laboratory is here presented. The results obtained point out the complexity of TAGS crystallization in vegetable oils, entangling nucleation, crystal growth, and secondary crystallization. During nucleation, the involvement of local-order and sporadic nucleation depends on the cooling rate used. In contrast, secondary crystallization is involved in crystal growth. All of these events are engaged during TAGS bulk crystallization in processes occurring not sequentially but in parallel. The Avrami model does not consider all of these phenomena. Future research in TAGS crystallization must focus on developing more complex models that include the different events involved during nucleation and crystal growth. © 2002 by CRC Press LLC.

publication date

  • 2002-01-01