Droplet size determination in food emulsions: comparison of ultrasonic andlight scattering methods

Ultrasonic velocity and attenuation spectra (1-5 MHz) were measured for a s eries of corn-oil-in-water emulsions (20 wt% oil in 2 wt% polyoxyethylene s orbitan monolaurate) with a range of different mean droplet diameters (0.5- 1.5 mum). Multiple scattering theory was used to calculate mean diameters f or each emulsion from both spectra. Droplet size was also determined using two commercial light scattering instruments. All techniques showed the same general trend of decreased size with increased degree of homogenization bu t there was only limited quantitative agreement between the various measure ment techniques. (C) 2001 Elsevier Science Ltd. All rights reserved.