Influence of Emulsifier Mixtures on Non-isothermal Fat Crystallization 
Daels, E., Rigolle, A., Maertens, J. & Foubert, I., KU Leuven 
Kortrijk, Belgium

Industry’s interest in the use of emulsifiers to manipulate fat crystallization is continuously increasing. The influence of different emulsifiers on fat crystallization has been studied a lot. The objective of this study was however to investigate the influence of mixtures of different emulsifiers, something that has not been reported on before in scientific literature although mixtures of emulsifiers are applied in industrial practice. 
The three emulsifiers which were used in this study were commercially available monoglycerides (M), polyglycerol esters (P) and lecithin (L). Next to pure M, P and L, binary and ternary mixtures of M, P and L were added to two different ‘host’ fats. The total amount of emulsifiers was set to 1,5% and a statistically sound mixture design was used in order to obtain as much information as possible. The obtained mixtures were analysed for their non-isothermal crystallization and melting behavior by DSC. 
It was observed that the influence on the crystallization and melting behavior depends on the type of emulsifier. The observed trends were similar for both ‘host’ fats. If a single type of emulsifier was added, the influence on the crystallization behavior corresponded to the literature: M and P accelerated crystallization to a similar extent, while L had no significant effect. From the mixture design it could be deduced that M and P and M and L work antagonistically while P and L show no significant interaction. When mixing the three emulsifiers a slight synergistic effect was observed, but the onset of crystallization was never higher than when pure M or P were added. The addition of emulsifiers (pure or in mixtures) had no significant effect on the amount of crystallization (as deduced from the area under the DSC curve). 
When focusing on the melting behavior, emulsifiers (pure and in mixtures) reduced the offset of melting of both ‘host’ fats. The mixture design showed that addition of L has the biggest lowering influence on the offset of melting, while the effects of M and P are of a similar magnitude. Antagonistic effects were detected between M and L and between M, P and L. 
It could thus be concluded that addition of some emulsifiers indeed positively influences the crystallization properties without leading to sensory problems due to a higher melting point.  However, it was not possible to obtain a stronger effect by mixing different types of emulsifiers.