Encapsulation and Stabilization of Oily Substances by Protein and Carbohydrate

Abstract

The solubilization phenomenon of fats and oils observed in a protein and carbohydrate solution was applied to an encapsulation process of oily substances. Rice bram oil as a model oily substance was solubilized into the micellar solution consisting of 60% by weight of corn syrup solids (35 Dextrose Equivalent) and 1% by weight of polypeptone as nitrogen obtained from commercial pork extract. The resulted oil solubilizate was subjected to vacuum drying at 60°C and granulated. The oil solubilizate was solidified without oil separation during drying. The higher oil content and smaller particle size of the granules caused less dispersibility of oil and more surface oil measured by n-hexane washing at room temperature. Encapsulated oil content of the granules ranged from 20% to 60% (w/w) depemding on in initial oil content. Scanning electron microscopic observation revealed the porous structure of the granules and suggested encapsulation of oil into the continuous protein-carbohydrate matrix. Oxidation stability of oil during storage at 60°C was apparently improved by encapsulation into the matrix.