EJPAU 2008. Bortnowska G. THE EFFECT OF COMPETITIVE ADSORPTION BETWEEN PROTEINS OF DRIED EGG YOLK AND TWEEN 65 ON THE STABILITY AND MICROSTRUCTURE OF OIL-IN-WATER EMULSIONS

Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.

2008
Volume 11
Issue 3

Topic:

Food Science and Technology

ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES

Bortnowska G. 2008. THE EFFECT OF COMPETITIVE ADSORPTION BETWEEN PROTEINS OF DRIED EGG YOLK AND TWEEN 65 ON THE STABILITY AND MICROSTRUCTURE OF OIL-IN-WATER EMULSIONS, EJPAU 11(3), #01.
Available Online: http://www.ejpau.media.pl/volume11/issue3/abs-01.html

THE EFFECT OF COMPETITIVE ADSORPTION BETWEEN PROTEINS OF DRIED EGG YOLK AND TWEEN 65 ON THE STABILITY AND MICROSTRUCTURE OF OIL-IN-WATER EMULSIONS

Grażyna Bortnowska
Department of Food Technology, West Pomeranian University of Technology, Szczecin, Poland

ABSTRACT

Stability of the oil-in-water emulsions composed of 30% (w/w) rapeseed oil and emulsifying mixtures containing dried egg yolk and Tween 65 were investigated. It has been shown that, stability of emulsions was in range from 37.5% to 58.2% and increased in most cases with the addition of emulsifiers, particularly Tween 65. It was found that surface protein concentration in emulsions decreased as concentration of Tween 65 increased, as the result of competitive adsorption. Changes in interfacial protein concentration probably caused instability of emulsions, observed as oiling off effect, especially in samples heated at 80°C and containing 2.0% (w/w) dried egg yolk and 0.8 or 1.0% (w/w) Tween 65. Furthermore, increase of synthetic emulsifier concentration decreased average droplet diameters D [3,2] from 1.42 mm to 0.28 mm, considerable increasing interfacial areas. Composition of the emulsifying mixtures affected modal diameter of oil droplets especially in the emulsions containing: 0.2; 0.6 and 1.0% (w/w) of dried egg yolk, what may be explained by the fact that the mixtures exhibited different emulsifying properties in the studied range of concentrations. Visual inspection of the investigated emulsions in the microscope showed that all emulsions had individual oil droplets with no signs of flocculation.

Key words: oil-in-water emulsion, dried egg yolk, Tween 65, competitive adsorption, surface protein concentration, emulsion stability.

Grażyna Bortnowska
Department of Food Technology,
West Pomeranian University of Technology, Szczecin, Poland
Papieża Pawła VI St. 3, 71-459 Szczecin, Poland
Phone: (091) 449 65 26
email: Grazyna.Bortnowska@zut.edu.pl

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