Effect of cold plasma on the physicochemical characteristics of granular cold water swelling maize starch

Granular cold water swelling (GCWS) starch is a physically modified starch with several potential applications in instant foods. Recently, some studies have revealed the beneficial effects of cold plasma (CP) treatment on improving the functional properties of starch. However, the effects of CP on GCWS has not been addressed yet. Therefore, this study assessed the influence of dielectric barrier discharge (DBD) cold plasma treatment time (1, 2, 3, and 4 min) on various attributes of GCWS maize starch. Increasing the CP treatment time increased the water absorption, solubility, viscosity, and freeze-thaw stability of GCWS maize starch, while, decreased its relative crystallinity and turbidity. FTIR results indicated that the functional groups along backbone remained unchanged upon CP treatment. Morphological analysis revealed that the starch granules preserved their integrity during CP treatment. However, increasing the duration of CP treatment resulted in the formation of microcavities and fissures on the surface of GCWS starch granules. The textural and rheological characteristics of GCWS starch pastes were improved by CP treatment. It seems that CP treatment might lead to an interconnected structure within the starch network and reinforce the starch paste.