TY - JOUR
T1 - Kinetic study of aggregation of milk protein and/or surfactant-stabilized oil-in-water emulsions by Sedimentation Field-Flow Fractionation
AU - Kenta, Stella
AU - Raikos, Vassilios
AU - Vagena, Artemis
AU - Sevastos, Dimitrios
AU - Kapolos, John
AU - Koliadima, Athanasia
AU - Karaiskakis, George
PY - 2013/8/30
Y1 - 2013/8/30
N2 - Milk proteins are able to facilitate the formation and stabilization of oil droplets in food emulsions. This study employed Sedimentation Field-Flow Fractionation (SdFFF) to monitor changes in particle size distribution of freshly prepared emulsions with varying weight contributions of sodium caseinate (SC) and whey protein concentrate (WPC). The effect of the addition of Tween 80 (T) on the initial droplet size was also investigated. The results indicated that emulsifying ability follows the order Tween 80 > WPC > SC, with corresponding weight average droplet diameter of 0.319, 0.487 and 0.531 μm respectively, when each of the above emulsifiers was used solely. The stability of sodium caseinate emulsions was studied at 30.5 and 80.0 °C by measuring the particle size distribution for a period of 70. h. Emulsions withstood the temperatures and exhibited an initial increase in particle size distribution caused by heat-induced droplet aggregation, followed by a decrease to approximately the initial droplet size. The rate of droplet aggregation depends on the severity of thermal processing, as revealed by the kinetics of particle aggregation during aging at different temperatures. Comparison of the experimental rate constants found from SdFFF, with those determined theoretically gives invaluable information about the oil droplet stability and the aggregation mechanism. Based on the proposed mechanistic scheme various physicochemical quantities, which are very important in explaining the stability of oil-in-water emulsions, were determined. Finally, the advantages of SdFFF in studying the aggregation of the oil-in-water droplets, in comparison with other methods used for the same purpose, are discussed.
AB - Milk proteins are able to facilitate the formation and stabilization of oil droplets in food emulsions. This study employed Sedimentation Field-Flow Fractionation (SdFFF) to monitor changes in particle size distribution of freshly prepared emulsions with varying weight contributions of sodium caseinate (SC) and whey protein concentrate (WPC). The effect of the addition of Tween 80 (T) on the initial droplet size was also investigated. The results indicated that emulsifying ability follows the order Tween 80 > WPC > SC, with corresponding weight average droplet diameter of 0.319, 0.487 and 0.531 μm respectively, when each of the above emulsifiers was used solely. The stability of sodium caseinate emulsions was studied at 30.5 and 80.0 °C by measuring the particle size distribution for a period of 70. h. Emulsions withstood the temperatures and exhibited an initial increase in particle size distribution caused by heat-induced droplet aggregation, followed by a decrease to approximately the initial droplet size. The rate of droplet aggregation depends on the severity of thermal processing, as revealed by the kinetics of particle aggregation during aging at different temperatures. Comparison of the experimental rate constants found from SdFFF, with those determined theoretically gives invaluable information about the oil droplet stability and the aggregation mechanism. Based on the proposed mechanistic scheme various physicochemical quantities, which are very important in explaining the stability of oil-in-water emulsions, were determined. Finally, the advantages of SdFFF in studying the aggregation of the oil-in-water droplets, in comparison with other methods used for the same purpose, are discussed.
KW - SdFFF
KW - emulsion
KW - sodium caseinate
KW - whey protein
KW - Tween 80
KW - kinetics of aggregation
UR - http://www.scopus.com/inward/record.url?scp=84881315835&partnerID=8YFLogxK
U2 - 10.1016/j.chroma.2013.07.061
DO - 10.1016/j.chroma.2013.07.061
M3 - Article
AN - SCOPUS:84881315835
SN - 0021-9673
VL - 1305
SP - 221
EP - 229
JO - Journal of Chromatography A
JF - Journal of Chromatography A
ER -