Research on Crystallization and Melting Behaviors of Rice Bran Oil

Abstract

In this paper, the isothermal and non-isothermal crystallization and melting behaviors of rice bran oil (RBO) are studied, and the composition of the precipitates under cold temperatures from RBO is analyzed.The results show that the isothermal shear rheology is an effective method to characterize the cold performance of RBO. With the increasing of the cooling rate, the onset crystallization temperature of RBO gradually decreases, and the melting enthalpy gradually decreases before it finally becomes stable. The crystal form of the precipitates from RBO after stored at 4 ℃ for 90 days is mainly β form, and its melting peak temperature is at 21.5 ℃. The two crystallization peak temperatures are 5.6 ℃ and - 43.9 ℃,respectively. Compared with virgin RBO, the relative content of palmitic acid in the precipitates increases significantly, and the relative content of oleic and linoleic acids decreases obviously.

Keywords

• rice bran oil
• crystallization
• melting
• crystal form
• cold performance