Microscopic approach of the crystallization of tripalmitin and tristearin by microscopy

Abstract

The crystallization behavior of lipids has important implications in industrial processing of food products, whose physical characteristics depend largely on crystallized fats. The study of the crystallization behavior and polymorphism of a pure lipid system is of great scientific importance as a means of gaining an understanding of the phenomena involved, serving as basic knowledge to help guide the addition or removal of these compounds in different raw materials. The crystallization behavior and polymorphism of pure tripalmitin (PPP) and tristearin (SSS) were investigated by Polarized Light Microscopy (PLM) and Differential Scanning Calorimetry (DSC) under different crystallization conditions. The polymorphic forms (β' and β) of PPP and SSS exhibited different morphologies depending on how they were obtained, either from α form recrystallization or from isotropic melt. Crystallization in the β form was faster in SSS than in PPP, indicating that the process occurs faster in TAGs composed of longer fatty acid chains. Both β' and β polymorphic forms were obtained from α form recrystallization, albeit with predominance of the β form.

Keywords: Microscopy; Polymorphism; Triacylglycerols; Tripalmitin; Tristearin.