The rele of chain length and an emulsifier on the polymorphism of mixtures of triglycerides

Abstract

The appearance of the β′ form in the α‐β transformation in tristearin is hardly detectable. On the other hand, in mixtures of tristearin and tripalmitin at different ratios, β′ formation has been observed to be favored. This observation confirms the statement in the literature that in mixtures of different chain lengths orthorhombic packing is stabilized. When an emulsifier was added to the mixtures, both the β′ and β formation were inhibited. The effect caused by the addition of the emulsifier as an impurity to tristearin is compared to that caused by the addition of tripalmitin: their effects, although both kinetic, were very different. In spite of this difference, they both have implications in the confectionery and fats industries.

Composition and thermal profile of crude palm oil and its products

“…Garti et al (19) used the DSC technique to study the role of TG mixtures on the stabilization of the β′ form. They indicated that the first peak of the heating thermogram corresponds to the melting of the α form, while the last peak corresponds to the melting of the β form.…”

Differential scanning calorimetry: A potential tool for discrimination of olive oil commercial categories

“…Hagemann et al [29] observed that OOO, as standard, could exhibit four polymorphic forms (␤ 3 , ␤ 2 , ␤ 1 and ␤), which melt at −12, −8, −5 and 5 • C, respectively. The ␤ -␤ transformation was reported to be sterically hindered in oil and fats where the mix of different chain length TAG reduced the efficiency of interplanar packing [30]. Thus, several ␤ forms generally occurred before transformation in the ␤ form [30].…”

“…The ␤ -␤ transformation was reported to be sterically hindered in oil and fats where the mix of different chain length TAG reduced the efficiency of interplanar packing [30]. Thus, several ␤ forms generally occurred before transformation in the ␤ form [30]. Further and more detailed information on TAG polymorphic forms in olive oils could be obtained by coupling DSC with X-ray diffraction, as these tandem techniques were already applied to the analysis of polymorphic crystal forms of other vegetable oils [31].…”

Hydrodynamic, thermo-analytical and molecular structural investigations of enzyme interesterified oil and its thermo-oxidative stability by thermogravimetric analysis

“…This change can be attributed to the change in different polymorphic form of the oils. Based on literature reports (Garti et al, 1989;Tan and Man, 2002) it is assumed that two endothermic peaks of a fat/oil represent a and b polymorphs. Triacylglycerol exists in three different polymorphs, such as, a, b 0 and b forms.…”