Preparation and Properties of Starch-Based Colloidal Microgels

Abstract

Novel starch microgels were prepared by emulsion cross-linking and characterized with respect to shape, volume, and mass density. Starch microgels appear to be negatively charged (∼−50 mV), with a particle size varying as a function of the type of cross-linker (ca. 0.25-10 µm). Environmental scanning electron microscopy observations show a dependence of the particle swelling on the cross-linking density. Viscosimetry reveals that starch microgels behave as charged polymers, where the reduced viscosity increases with dilution (anomalous viscosity behavior) for sufficiently low κa (ca. κa < 3), the ratio of the particle radius (a), and the Debye length (κ −1 ). Analogous results are obtained for reference-charged rigid silica spheres, which approach the hard sphere limit for increasing ionic strengths. The shape of the microgels appears to play a minor role in the anomalous viscosity behavior, which is more likely dominated by electrostatic effects. C 2002 Elsevier Science

Physical properties and loading capacity of starch-based microparticles crosslinked with trisodium trimetaphosphate

“…The fact that no TSTP peaks can be identified suggests that few or no crosslinker remained in a crystal state inside the microparticles. This result was consistent with that Dziechciarek et al (2002) reported. However, different observation was reported by Malafaya et al (2006).…”

“…Particularly, few studies have concerned about the effect of crosslinking density on the physical properties and loading capacity of TSMs. Moreover, conflicting results on the structural organization of TSMs were reported by different researchers (Dziechciarek et al, 2002;Malafaya et al, 2006). Therefore, these issues will need further study.…”

“…Malafaya et al (2006) suggested that a 6 h reaction period was the optimal time in terms of crosslinking and morphological stability of the starch microspheres. Dziechciarek et al (2002) prepared starch microspheres with ECH and TSTP, respectively. They found that the size of TSTP-crosslinked starch microspheres is about 10 times larger than that crosslinked with ECH.…”

Aqueous Two-Phase Systems for Microencapsulation in Food Applications

“…Chemical crosslinking has been a predominant approach of solidification (Yu and Liu, 1994;Dziechciarek et al, 2002;Li et al, 2009), but non-covalent approaches relying on recrystallization (Reslow et al, 2002) have also been used. This approach has been used to make microcapsules for different purposes within the field of controlled release.…”

Preparation and Characterization of Starch Nanoparticles from Potato Starch by Combined Solid‐State Acid‐Catalyzed Hydrolysis and Nanoprecipitation

“…A variety of methods based upon high‐power ultrasonication, microemulsion crosslinking, nanoprecipitation, enzymolysis and recrystallization and so on have been developed to synthesize SNPs. Nanoprecipitation is one of the most effective methods for preparing SNPs; this approach is also called the solvent exchange method, in which starch granules are dissolved in a solvent and precipitated in a nonsolvent to obtain SNPs.…”