Understanding the multi-scale structure and functional properties of starch modulated by glow-plasma: A structure-functionality relationship

The functional properties of starch related to thickening and gelling were modulated by altering its hierarchical structure using nitrogen or helium glow-plasma. The microstructural, mesoscopic, and molecular scale structures and the functional properties (gelatinization and pasting) before and after glow-plasma modification were evaluated. A novel schematic model on structure-functionality relationship was proposed for glow-plasma modified starch. Specifically, gelatinization and pasting were facilitated by multi-scale structural disorganizations. While surface corrosion degraded shear resistance for swollen granules, polymerization/crosslink induced by glow-plasma made starch molecules more branched and networked to not only hinder their stretch during granule swelling and after granules being ruptured, resulting in decreased maximum viscosity and overall viscosity, and increased hightemperature paste stability, but also limit their rearrangement during cooling, causing weaker retrogradation and enhanced paste cooling stability. This study suggests that glow-plasma modified starch may serve as a potential high-safety thickener or gelling agent for various foods. (C) 2015 Elsevier Ltd. All rights reserved.