Stability of a concentrated oil-in-water emulsion model prepared using palm olein-based diacylglycerol/virgin coconut oil blends: Effects of the rheological properties, droplet size distribution and microstructure

Siou Pei Ng; Oi Ming Lai; Faridah Abas; Hong Kwong Lim; Chin Ping Tan

doi:10.1016/j.foodres.2014.08.045

Stability of a concentrated oil-in-water emulsion model prepared using palm olein-based diacylglycerol/virgin coconut oil blends: Effects of the rheological properties, droplet size distribution and microstructure

Food Res Int. 2014 Oct:64:919-930. doi: 10.1016/j.foodres.2014.08.045. Epub 2014 Sep 6.

Authors

Siou Pei Ng¹, Oi Ming Lai², Faridah Abas³, Hong Kwong Lim¹, Chin Ping Tan⁴

Affiliations

¹ Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
² Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
³ Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
⁴ Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Electronic address: tancp@upm.edu.my.

PMID: 30011735
DOI: 10.1016/j.foodres.2014.08.045

Abstract

The rheological properties, microstructure, textural properties, colour and droplet size distribution of mayonnaise-like emulsion models prepared using 10-30wt.% of palm olein-based diacylglycerol (POL-DAG) oil were compared with those of the control (100wt.% VCO) model. There were significant (P<0.05) differences in the particle size distribution of the oil droplets, the textural properties, and the rheological properties of the various emulsion models. The rheological analysis included the determination of the flow curves, yield stress, thixotropy, apparent viscosity, and viscoelastic parameters. The concentrated oil-in-water (O/W) emulsion with 30wt.% POL-DAG substitution exhibited high thixotropy. The POL-DAG content had a substantial effect on the rheological properties of yield stress, storage modulus (G') and loss modulus (G″). The pseudoplastic behaviour of the emulsions was demonstrated. The size of the particles in the 30% POL-DAG-substituted emulsion was dramatically increased after one day and 30days of storage. All of the emulsion samples with POL-DAG substituted for VCO showed a relatively non-uniform bimodal droplet size distribution after one day of storage. In general, substitution of 10-20wt.% POL-DAG oil is appropriate for preparing O/W emulsions that had flow curves and textural properties similar to those of the control sample.

Keywords: Droplet size; Emulsion; Flow behaviour; Oil blends; Palm diacylglycerol; Rheological property; Virgin coconut oil.