Heat capacity of tristearin in the presence of food emulsifiers

Self Cite

Proton magnetic resonance measurements were performed onα andβ polymorphs of tristearin crystals. T1 relaxation time was measured with the Bruker PC Minispec at 20 MHz and 37° on the pure triglyceride crystals and therefore on tristearin crystallized in the presence of different solid surfactants. A significant negative correlation for T1 values and different compositions ofα andβ polymorphs in a mechanical mixture was found. The shortening of T1 relaxation time of theβ form was found to be different for the various types of the added surfactants while they have no effect on the relaxation time of theα form. A model was proposed according to which the presence of additives, such as surfactants, generates vacancies within the crystal lattice of triglyceride and enhances the freedom of rotation of the fat molecule about the terminal carbon‐carbon bond.

Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 83%

mentioning

confidence: 99%

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NMR relaxation studies to explore the role of emulsifier in tristearin polymorphic transformation

Azoury¹,

Aronhime

Sarig

et al. 1988

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“…Presumably, during slow cooling the less compatible surfactants aggregate into clusters and then decrease their effect; on the contrary, it seems that the performance of sorbitan monostearate is not affected by the previous solidification rate because the molecules do not form clusters even during slow cooling. The particular structural affinity can be further supported by the Cp measurements (21) and in phase diagrams (24}. It is interesting to note the difference between addition of emulsifier and addition of tripalmitin at the same percentage.…”

Section: Effect Of Emulsifier On Polymorphism Of Tristearinmentioning

confidence: 68%

Dynamic control of polymorphic transformation in triglycerides by surfactants: The button syndrome

Aronhime

Sarig

Garti

1988

The kinetics of polymorphic transformations in monoacid saturated triglycerides and the influence caused by the presence of certain solid surfactants were investigated. Selected emulsifiers can be incorporated at the level of 10 wt% within the triglyceride, without changing the crystal lattice; on the other hand, their presence affects the heat capacity of the triglyceride and the NMR relaxation time T1. Following the polymorphic transformation both during aging and during heating in the DSC, it was observed that both the mechanism and rate of transformation of the triglyceride strongly depend on the kinetic conditions and on its own chemical structure. In conjunction with these results it also was observed that the effect of the emulsifier is strongly dependent on the transformation conditions. The kinetic effect of the additive on the solid‐solid transformation has been found to be strictly associated with its hydrophilic moiety structure; a model of molecular incorporation has been proposed which describes the arrangement of the surfactant molecules parallel to the triglyceride chains and formation of vacancies. The selectivity of the additive concerning its effect of dynamic controller of polymorphic transformations has been explained by its capacity to create hydrogen bonds with the neighboring triglycerides, which was called the “Button Syndrome.” The wide range of different additives and triglycerides used supplied a better understanding of the factors which determine the polymorphic and crystallization behavior in triglycerides.

“…The C p of a tristearoylglycerol is not affected. Acidan Ò and 3G1S Ò increase the C p of a and b across all temperature ranges, parallel to the C p of pure tristearoylglycerol [4,102].…”

Section: Miscellaneous Effectsmentioning

confidence: 99%

Crystallization of Fats: Influence of Minor Components and Additives

Smith¹,

Bhaggan²,

Talbot

et al. 2011

228

175

Over the years, there has been a steady stream of publications on the influence that minor components and additives have on the physical properties of fat continuous systems. These have been reviewed here. Both indigenous and added components are taken into account. The various materials have been discussed, ranging from partial glycerides and phospholipids to esterified sugars and polyols. Within the publications in this area, the (sub-)micron effects that these minor components have on nucleation, crystal growth, morphology, heat capacity and polymorphic stability have been described and discussed and, sometimes, explained. Similarly, the effects on a macroscopic level, such as visual aspects, melting profiles, posthardening and rheology have been the subject of research. Although limited compositional information, especially of additives, hinders appropriate discussions of the relevant mechanisms, some generic guidelines as to what type and strength of effect can be expected have been derived. As a general rule, a more significant influence is observed when the acyl group of the minor component (where present) is similar to those present in the fat itself. Additives may have different effects depending on the fat they are added to, their concentration and the temperature, especially with increasing undercooling (which typically reduces the effect of additives).