Coconut Oil Crystallization on Tripalmitin and Tristearin Seed Crystals with Different Polymorphs

Abstract

This study evaluates the influence of the polymorphs of triacylglycerol (TAGs) seed crystals on the crystallization of coconut oil (CO) using seeding techniques. Tripalmitin (PPP) and tristearin (StStSt) with three polymorphs (α, β′, and βα forms) were used as the seed materials. β form seed crystals were prepared by transforming in the solid state from the α form (βα) and by annealing TAG powder (βann). The CO crystallization on the TAG seed crystals was observed at 20 °C using differential interference contrast microscopy and synchrotron radiation X-ray diffraction. The seed crystals with different polymorphs of PPP and StStSt promoted the nucleation of the β′ form of CO by heterogeneous nucleation. The seed crystals with the β′ form were the most effective accelerators, indicating that polymorphic matching between seed crystals and CO strongly induced the nucleation of CO by epitaxial growth. A longer TAG fraction (such as LMP, PPP, etc., L is lauric acid, M is myristic acid) of CO probably grew on the surface of the βann seed via the template effect with the same orientation as the seed. These results indicate that the seed crystal polymorphs significantly affect the efficiency of CO crystallization. Efficient seedings can be used to improve the physical properties of CO via fractionation.

Interactive Polymorphic Crystallization Behavior in Eutectic Triacylglycerol Mixtures Containing Molecular Compound Crystals

“…Epitaxial effects may be particularly feasible given the results from a recent crystal seeding study . In this study, the polymorphic crystallization of TAGs in coconut oil was controlled by using seed crystals of high-melting TAGs.…”

“…Epitaxial effects may be particularly feasible given the results from a recent crystal seeding study. 49 In this study, the polymorphic crystallization of TAGs in coconut oil was controlled by using seed crystals of high-melting TAGs. The seeding effects were most remarkable when the polymorphic form of these seed crystals was the same as that of the to-becrystallized TAGs (polymorph−polymorph matching).…”

Monobehenin and Tribehenin as Modifiers in the Crystallization of Palm Oil and Palm Stearin

“…Mahisanunt et al. [ 31 ] investigated the influence of the polymorphs of seed crystals, PPP and SSS with three polymorphs (α, β′, and β forms) were used as the seed materials in CO. They observed that the polymorphic matching between seed crystals and CO induced nucleation of CO by epitaxial growth.…”

“…[ 32 ] When the subcell dimensions between the seeds and the fat being crystallized are well‐matched, the crystallization trends to be induced by epitaxial growth. [ 31 ] With the addition of α‐form MB, the crystallization of β‐form PS was retarded (Figure 5) due to the subcell mismatching. In contrast, BBB transforms to β form easily and promotes the β formation of PO and PS significantly (Figure 3C,D).…”

“…Recently, Mahisanunt et al observed the epitaxial growth of CO on the seed crystal of PPP and SSS by using differential interference contrast microscopy. [31] It is known that the better structural affinity of components, the more chemically similar the components are, and the greater is their interaction and better compatibility. [13,29] According to the research conducted by Basso et al, [7] the addition of MB to PO resulted in the formation of a large number of seeds of smaller size.…”