Commercial Starch Behavior When Impregnated with Food Additives by Moderate Temperature Supercritical CO₂ Processing

Abstract

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.

Water free incorporation of shark liver oil into starch microparticles by supercriticalCO2impregnation at low temperature

“…A relative affinity of MSM to the supercritical CO 2 was expected due to specific interactions with carbonyl groups resulting from modification of the starch with octenylsuccinic anhydride. Nevertheless, the absence of volumetric expansion for the MSM suggests that the number of carbonyl groups in the MSM was not high enough for physical observation of its affinity to supercritical CO 2 ; however, the impregnation occurred because the SLO is solubilized by CO 2 and different types of starches can adsorb CO 2 (Villegas et al, 2020).…”

“…The volumetric expansion (%) of MSM in supercritical CO 2 under training test conditions (120 bar and 40 and 60°C) was measured in a high‐pressure phase monitor (Thar Technologies Inc., SPM20, Pittsburgh, PA) (Villegas et al, 2020). In this equipment, the CO 2 was pressurized using an automatic syringe pump (Thar Technologies Inc., P54) maintained at 1°C with the aid of a recirculating refrigeration bath (Julabo, F12‐ED, Seelbach, Germany).…”

“…These studies aimed at impregnation/encapsulation in a water free medium and at low temperatures. The conditions chosen were therefore based on the research of Machado et al (2016) and of Villegas et al (2020). The autoclave was rapidly depressurized (during approximately 1 min) by fully opening the autoclave outlet valve, and SLO‐incorporated MSMs were collected.…”

“…The dispersions remained for 18 hr and then were placed in quartz cubes for reading. Particle size measurements were taken at absorbance levels of 0.1–0.2 with visual verification of the homogeneity and stability of the dispersion (Villegas et al, 2020).…”

“…Considering that octenylsuccinic anhydride starch is a polymer with incorporated hydrophobic groups and can interact with supercritical CO 2 (Villegas et al, 2020) and also because these groups are applied as additives in food processing as a substitute for conventional starch, the aim of this work was to form SLO‐incorporated modified starch microparticles (MSMs) using supercritical CO 2 impregnation. In modified starches, the hydrophilic starch gains a hydrophobic element and becomes an amphiphilic molecule.…”