Effect of enzymatic depolymerization on physicochemical and rheological properties of guar gum

► Enzymatic hydrolysis of guar gum changed the rheological behavior from non-Newtonian to Newtonian-like behavior. ► Enzymatic hydrolysis reduced intrinsic viscosity of guar gum from 9 to 0.28. ► Enzymatic hydrolysis reduced consistency index of guar gum from 4.04 to 0.07. ► Depolymerization of guar gum increased the crystallinity index from 3.86 to 13.2. Depolymerization of guar gum using enzymatic hydrolysis was performed to obtain depolymerized guar gum having functional application as soluble dietary fiber. Enzymatic hydrolysis of guar gum significantly affected the physicochemical and rheological characteristics of guar gum. The depolymerized guar gum showed a significant increase in crystallinity index from 3.86% to 13.2% and flow behavior index from 0.31 to 1.7 as compared to native guar gum. Remarkable decrease in intrinsic viscosity and consistency index was also observed from 9 to 0.28 and 4.04 to 0.07, respectively. Results revealed that enzymatic hydrolysis of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency which could make it useful for incorporation in food products as dietary fiber without affecting the rheology, consistency and texture of the products.