Fat particle structure and stability of food dispersions

Abstract

ABSTRACT In this paper, we will briefly review the most recent work performed in our laboratory in the areas of structure and stability of food dispersions and specially the role of long-range oscillatory structural forces in controlling stability. We have developed a number of nondestructive experimental techniques to characterize the structure formation and stability in concentrated food emulsions and foams. These techniques include Kossel diffraction and the method of digitized optical imaging. We have used these techniques to investigate the effects of surfactant type (i.e. water soluble and oil soluble), proteins, gums, fat substitutes, temperature and shear rate on fat particle structure variations in food systems. It has been generally accepted that coalescence in foams and emulsions is controlled by the thinning and rupture of thin liquid films between bubbles or droplets. We have used a capillary force balance technique as well as our newly developed film tensiometer to unravel the details of surfactant/protein stabilization mechanisms in both emulsion and foam systems. In this paper, we first present the microscopic world of thin liquid films and then link it to the macroscopic observations obtained by us using Kossel diffraction and digitized optical imaging techniques in food systems.