Olive oil and lemon salad dressing microencapsulated by freeze-drying

An instantaneous food emulsion was formulated containing olive oil and lemon juice using combinations of polymers, such as Alginate (ALG), Arabic gum (AG), Maltodextrin (MD) and Carboxymethyl cellulose (CMC) and freeze-dried, aiming at the development of a new microencapsulated product. The characterization of particle size, the surface analysis by scanning electron microscopy, the X-ray diffraction and the differential scanning calorimetry were performed with the emulsions that showed a good oil encapsulation. Mixtures of maltodextrin and arabic gum showed the lowest average values of particle size. Moreover, these samples presented rounded shapes and some depressions shown by scanning electron microscopy and proved to be an amorphous material by X-Ray Diffraction. The glass transition temperatures of samples C (12.5 g/100 g MD and 7.5 g/100 g AG), 146.60 degrees C, and D (10 g/100 g MD and 8.5 g/100 g AG), 147.54 degrees C, were similar, because the type of polymers was similar. This study shows that it is possible to microencapsulate emulsion oil in water (1:1) by freeze-drying to use an instant sauce salad. (C) 2012 Elsevier Ltd. All rights reserved.