Links between single maltodextrin particles properties and powder functionality

Maltodextrins are extensively used in the food industry to shape the physicochemical properties of food products. This multiscale study investigates three different Dextrose Equivalent (DE) maltodextrins as model matrices to elucidate the relationship between techno-functional behaviors and single particle surface properties. It was evidenced that environmental variations and glass transition influence single particle properties, significantly impacting the powder bulk behavior. Utilizing Confocal Laser Scanning Microscopy (CLSM) and environmental Atomic Force Microscopy (AFM) at the single particle level, correlations between the wetting and nanomechanical properties of all maltodextrins were provided. It was revealed that wetting properties are directly DE dependent, as higher DE maltodextrins had shorter wetting times. Moreover, glass transition plays a critical role in determining surface elasticity and capillary adhesion, as it alters both physicochemical properties and particle morphology. Indeed, a decrease of the Young modulus with Relative Humidity (RH) and glass transition correlated with the increase of capillary forces. This was corroborated by Scanning Electron Microscopy (SEM) and Specific Surface Area (SSA) measurements at different RH. These findings confirmed that glass transition drives particle morphology, with global surface smoothing and swelling occurring in the rubbery state.