Stability of whippable oil-in-water emulsions: Effect of monoglycerides on crystallization of palm kernel oil

- GMU, GMS, DATEM and LACTEM strongly affect the rheological properties of emulsions.
- LACTEM based PKO emulsions ranged from highly to low viscous.
- Aggregation of emulsions were independent of fat polymorphic transformations.

The effect of selected monoglycerides on droplet morphology and rheology of palm kernel oil emulsions was studied. Combination of lactic acid ester of monoglycerides (LACTEM) and unsaturated monoglycerides (GMU) yielded highly viscous emulsions caused by partial coalescence. LACTEM combined with saturated monoglycerides (GMS) or diacetyl tartaric acid ester of monoglycerides (DATEM) gave low-viscous emulsions. The rheological behavior was found not to be related to polymorphic transformations of fat in the emulsions.A possible relationship between structural changes of emulsions and the effect of monoglyceride crystallization behavior of PKO was examined by studying the monoglycerides' influence on crystallization of bulk PKO. Polymorphic transformation, crystallization kinetics and melting/crystallization profile of bulk PKO were analyzed. The monoglycerides had minor effect on crystallization behavior of bulk PKO compared to the major impact on emulsion stability. This indicates that emulsifiers act differently in bulk and dispersed fat. For PKO the structural changes of the emulsions were independent of the effects of monoglycerides on the crystallization of bulk fat.