Polymorphism of stabilized and nonstabilized tristearin, pure and in the presence of food emulsifiers

Abstract

Abstract The polymorphism of tristearin (SSS) was studied by means of differential scanning calorimetry and powder X‐ray diffraction. The influence of 5% in weight of different food emulsifiers—i.e., 1‐monostearin, sorbitan tristearate, and sugar monostearate—was also studied. Because polymorphism is sensitive to thermal treatment, two thermal conditionings were applied. According to the dynamic process (melting, quenching, and heating at 5°C/min), SSS showed three polymorphic forms: α, β′, and β 1 . The presence of the emulsifiers hindered the β′→β transformation, and a destructured β 2 form was recorded. According to the stabilization process (stabilization at 57°C for various periods of time), SSS showed two β′ forms: β 2 ′ and β 1 ′ . Three hours of stabilization were necessary to recover the whole triglyceride under the β form. The emulsifiers slowed down the polymorphic transition rates. Indeed, after six hours of stabilization, mixtures of β′ and β were observed. Sugar monostearate seemed to have the most powerful effect on the transition kinetics because large amounts of α form were detected.