Comparative analysis of dietary fiber activities of enzymatic and gamma depolymerized guar gum

Gamma radiation depolymerized guar gum (RDGG) and partially enzymatically hydrolyzed guar gum (PHGG) were compared for their intrinsic viscosity (eta), molecular weight distribution, proximate composition, mannose to galactose (M/G) ratio, glucose and bile acid dialysis retardation index (GDRI & BDRI) and production of short chain fatty acids (SCFA) during model intestinal fermentation. RDGG had a higher eta value (37.90 ml/g) compared to PHGG (28.58 ml/g). PHGG had one peak with M-w of 12 kDa, while RDGG showed three peaks (M-w 1323.9 kDa, 614.02 kDa and 38.38 kDa) when subjected to gel permeation chromatography. Both RDGG and PHGG had similar proximate composition and M/G ratio. RDGG demonstrated higher GDRI and BDRI of 21.74% and 56.63% while PHGG had values of 12.74% and 0% respectively. Similar contents of SCFA were obtained using either RDGG or PHGG as carbon source. RDGG thus demonstrated improved physiological properties compared to enzyme hydrolyzed counterpart in in vitro assays. (C) 2015 Elsevier Ltd. All rights reserved.