Addition of sugars influences color of oil-in-water emulsions.
The influence of glucose, fructose, lactose, and glycerol on the color and appearance of surfactant-stabilized oil-in-water emulsions containing a red dye was investigated. A stabilized (Tween-20) oil-in-water emulsion was diluted into sugar solutions to give a range of oil droplet and sugar concentrations. Tristimulus coordinates (L, a, b) and reflectance spectra were measured using a spectrophotometer. With increasing sugar concentration, reflectance spectra shifted to lower reflectance values. Tristimulus coordinates were reduced by approximately 50% for emulsions containing high concentrations of sugar. Adding fructose to emulsions reduced L, a, b values more significantly than adding glucose, lactose, or glycerol. Tristimulus coordinates remained constant when the temperature was raised from 20 to 80 degrees C. The experimental results were explained in terms of the change of relative refractive index at the water-oil interface. The results have important implications for the food industry as they offer a new means to control and optimize the color of food emulsions.
Weiss
J
J
Colloidal and Interfacial Food Science Laboratory, Department of Food Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, USA. jweiss1@utk.edu
Liao
W
W
D002241:Carbohydrates / Q000737:chemistry*; D003116:Color; D004655:Emulsions / Q000737:chemistry*; D008027:Light; D009821:Oils; D012542:Scattering, Radiation; D014867:Water
D002241:Carbohydrates; D004655:Emulsions; D009821:Oils; D014867:Water