Study of Hydration Kinetics and Rheological Behaviour of Guar Gum

BACKGROUND Guar galactomannan is a plant polysaccharide with extensive applications in food, paper, textile and petroleum industries. The main advantages for using guar are its low cost, easy availability and capacity to form viscous solutions and gels at low concentration. Additionally, chain architecture of guar galactomannan can be selectively modified to tailor properties of guar formulations and open up new opportunities for guar usage.The parameters such as hydration of guar, intrinsic viscosity measurements for determining the molecular weight of guar, rheological properties of guar were studied. RESULTS Experimental data have been correlated with the different models: flow curves with the Cross, Carreau and MeterBird model .The volume mean size of guar gum was 53.7μm and the molecular weight of guar near neutral pH was 967000 g/mol which were determined by intrinsic viscosity measurements. Hydration kinetics followed the logarithmic model. The behaviour of guar was interpreted in terms of Carreau model. CONCLUSION In this investigation the parameters such as hydration of guar, intrinsic viscosity measurements for determining the molecular weight of guar, rheological properties of guar were studied which would be very useful in modifying chain architecture of galactomannan to alter its properties which would open new opportunities for the use of guar.