Physicochemical, molecular, emulsifying and rheological characterizations of sage (Salvia splendens) seed gum

The objective was to investigate the physicochemical, molecular, rheological, and emulsifying properties of water soluble-sage seed gum (WSG). WSG mainly comprised galacturonic acid and xylose. FTIR and NMR analyses confirmed the presence of pectic polysaccharides in WSG. Additionally, the molecular weight of WSG was higher than that of pectin standard. Compared to pectin standard solutions, WSG solutions exhibited higher shear thinning behavior and higher values of apparent viscosity (η_a,100) and consistency index (K) in steady shear measurements. According to the results of frequency sweep test, the dynamic moduli (G' and G″) for WSG solutions were increased with increasing frequency and concentration. The changes in dynamic moduli of WSG solutions as a function of aging time at 4 °C indicated that WSG could form a more rigid network than pectin standard. According to the results of temperature sweep test, the dynamic moduli of WSG solutions were higher than those of pectin standard solutions. Emulsion capacity and stability analyses indicated that WSG (58 and 56%, respectively) had better emulsifying properties than pectin standard (46 and 37%). In conclusion, compared to pectin standard, superior rheological and emulsifying properties observed in WSG might be related to higher molecular weight and protein content, respectively.