Effects of micronization on microstructure and rheological properties of guar gum

Micronized guar gum was prepared by a vibrating superfine mill with different micronization time of 15, 30, 45 and 60 min, and its microstructures and rheological properties were investigated. Untreated guar gum had a smooth and dense surface, and the surface of guar gum became loose and rough after micronization, which indicated the microstructure of guar gum was destroyed. Rheological behavior analysis showed that micronization treatment decreased the viscosity of guar gum, and the treated samples were more solid like than untreated guar gum. Due to agglomeration, the viscosity of guar gum reached the minimum value when the micronization time was 60 min.