Effects of pectin and heat-moisture treatment on structural characteristics and physicochemical properties of corn starch

The study investigates the role of pectin and heat-moisture treatment in modifying the physicochemical and structural properties of corn starch. The structural features and morphological, thermal and rheological properties of samples were characterized using techniques including microscope, SEM, DSC, FTIR, NMR, and rheometer. Results reveal that the pectin-starch mixture with the heat-moisture treatment shows an improved paste stability and a modified structure with a lowest value of retrogradation degree (39.7%), syneresis rate (6.33%), double helices content (26.5%), and leaching amylose content (22.7%). All of these can be ascribed to a fact that the heat-moisture treatment could enable a strong interaction of hydrogen bonds between pectin and starch molecules (amylose/amylopectin). The current findings suggest a potential use of the heat-moisture-treated pectin-starch paste in food industry.