1. NOVEL STARCH MODIFICATIONS: FABRICATION AND APPLICATIONS
- Author
-
Li, Peilong
- Subjects
- Colloidosomes, Patchy particle, Rheology, Starch modification
- Abstract
Starch as a food-grade thickener has been commonly used in food products to modulate textural properties. Beyond conventional swelling-based thickening, we explored novel platforms of starch modification: patchy particles and hollow particles. To fabricate patchy particles, a colloidal-fusion method was developed by grafting anionic amaranth starch (~1 μm) on cationic corn starch (> 10 μm) after partial gelatinization where starch polymer strands are dissociated then re-stitched. This starch has a negatively charged main body and positively charged patches. Such patchy particles self-assembled through electrostatic interactions into a shear-reversible thickener by trapping water in matrix and exhibited stronger thickening ability. The results demonstrate that the functional properties of starch suspension can be fine-tuned by manipulating the architecture (degree of patchiness and the charge density) of patchy particles. The application potential in food products with different pH levels and ionic strengths was also evaluated. Further, to fabricate hollow starch, a bottom-up method was developed to fabricate colloidosomes. The Pickering emulsion was annealed so the starch pastes at the interface, which then upon antisolvent precipitation integrated as rigid solid layer. Hollow starch was produced after the organic phase has been removed. The results demonstrated the hollow starch exhibited large specific volume therefore contributed to higher viscosity. Results showed that fabrication procedures and template composition affect the microstructure thus the functionality. Crosslinkable hollow starch can be synthesized using a palm oil as template, where the solid organic phase protects the structure during antisolvent precipitation and crosslinking reaction. The resulting crosslinked colloidosomes exhibit higher viscosity and stronger structural stability. The high-volume hollow starch showed potential to be used as a low-carb super-thickener and fat replacer. Both the concepts of modifying starch using patchy particles and hollow particles provide novel platforms for studying the rheological behavior of granular suspensions, and have also been demonstrated to be novel structurants in food systems.
- Published
- 2023