RHEOLOGY OF DOUBLE (W/O/W) EMULSIONS PREPARED WITH SOYBEAN MILK AND FORTIFIED WITH CALCIUM

Abstract

ABSTRACT The objective of this work was to study the rheological behavior of water-in-oil-in-water (w/o/w) emulsions prepared with soybean milk and sunflower oil, with different calcium solutions as the internal aqueous phase, in order to evaluate them as a vegetable substitute of whipped dairy cream. The obtained systems exhibited a creamy texture, which was attributed to the swelling of w/o droplets because of the osmotic gradient generated by the inclusion of soluble salts in the internal aqueous phase. A secondary factor could be the flocculation of w/o droplets due to the interaction of released calcium with soybean proteins at the interface. Consequently, the increase of calcium chloride content produced emulsions with higher consistency. A pasteurization produced flocculation and coalescence of w/o droplets only at high calcium chloride content. These double emulsions could be a potential alternative to the whipped dairy cream, because of their texture, reduced fat content and calcium contribution. PRACTICAL APPLICATIONS This article deals with the formulation of novel calcium-fortified food emulsions prepared with soybean milk and sunflower oil. Because calcium needs to be isolated from soybean milk components (proteins and phospholipids), we proposed to include calcium salts in the internal aqueous phase of a water-in-oil-in-water (w/o/w) emulsion. The practical applications of this research could include the formulation of low lipid content emulsions and the isolation of a component which is incompatible with the continuous aqueous phase. Particularly, this work leads to the understanding of how the inclusion of calcium salts in the internal aqueous phase of a w/o/w emulsion prepared with soybean milk affects the rheology and microstructure of the system. The results led to the conclusion that these emulsions can work as a whipped dairy cream substitute with vegetal components, low lipid content and important calcium contribution.