Prediction of emulsion color from droplet characteristics: dilute monodisperse oil-in-water emulsions

The influence of droplet characteristics on the transmission of light throu gh dilute monodisperse oil-in-water emulsions was investigated in the prese nce and absence of dye. The turbidity spectra and tristimulus color coordin ates (L*, a*, b*) of a series of n-hexadecane oil-in-water emulsions with d ifferent disperse phase volume fractions (phi = 0-0.02 wt%), mean droplet r adii (r = 0.1-1 mum) and red dye concentration (0 and 0.002 wt%) were measu red. The dependence of the optical properties of colored and non-colored em ulsions on droplet size and concentration could be qualitatively described by light scattering theory. Nevertheless, there was relatively poor quantit ative agreement between theory and experiment because of the influence of t he measurement system on the optical properties of emulsions. The informati on presented in this paper will facilitate the formulation of dilute food a nd beverage emulsions with specific optical characteristics. (C) 2001 Elsev ier Science Ltd. All rights reserved.