Modulation mechanism of Mesona chinensis polysaccharide on structural evolution of corn starch cryogel during gelatinization.

The modulatory influences and underlying mechanisms of Mesona chinensis polysaccharide (MCP) on the structural evolution of corn starch (CS) cryogels during the gelatinization were systematically investigated in this work. During gelatinization, the interactions between MCP and starch chains accelerated the onset of gelatinization and disrupted the dense short-range hydrogen bonding of incompletely unfolded amylose and amylopectin. Furthermore, the MCP inhibited the short-term retrogradation of amylose starch through hydrogen bonding and steric hindrance in the cooling stage. MCP substantially regulated the gelatinization process of precursor hydrogels of CS cryogels, and ultimately affected the porous microstructure and physicochemical properties of the final freeze-dried cryogels. With the progression of gelatinization, the bulk density of composite cryogels first decreased significantly and then increased, while porosity exhibited the opposite trend. Meanwhile, the microstructure gradually evolved from a dense and heterogeneous state into a porous architecture with uniform pore distribution and moderate compactness. 9-min gelatinized CS-MCP cryogels displayed homogeneous honeycomb pores with interconnected architecture, high porosity and favorable water absorption capacity. This work advances the preparation theory and regulation strategies of starch cryogels, and provides new insights for achieving precision regulation of their microstructure and optimization of their functionalities.