Commercial Starch Behavior When Impregnated with Food Additives by Moderate Temperature Supercritical CO 2 Processing

The behavioral analysis of carrier materials in supercritical carbon dioxide (CO 2 ) is important for particle formation applications. In this work, the behavior of modified starches (Hi‐Cap 100, Purity Gum Ultra, and Fluidex) in supercritical CO 2 at 15 MPa and 60 °C is studied. Morphology and size profile of starch particles before and after contact with supercritical CO 2 and their solubility and volumetric expansion in supercritical CO 2 are analyzed. Morphology and size profiles of starch particles show physical changes; Purity Gum Ultra and Fluidex particularly show incremental changes in particle size. Solubility values for Hi‐Cap 100 and Purity Gum Ultra are 0.06 g/kg of CO 2 ; for Fluidex it is 0.14 g/kg of CO 2 . No volumetric expansion of pure starches mixed with ethanol is visibly detected; alterations are observed only in starches mixed with hydrated ethanol. Although the starches are chemically modified, which gives them hydrophobicity, their interaction with supercritical CO 2 is minimal.