Hydrolytic fragmentation of seed gums under microwave irradiation

Optimization of enzymatic hydrolysis of guar gum using response surface methodology

Guar gum is a polysaccharide obtained from guar seed endosperm portion. Enzymatically hydrolyzed guar gum is low in viscosity and has several health benefits as dietary fiber. In this study, response surface methodology was used to determine the optimum conditions for hydrolysis that give minimum viscosity of guar gum. Central composite was employed to investigate the effects of pH (3-7), temperature (20-60 °C), reaction time (1-5 h) and cellulase concentration (0.25-1.25 mg/g) on viscosity during enzymatic hydrolysis of guar (Cyamopsis tetragonolobus) gum. A second order polynomial model was developed for viscosity using regression analysis. Results revealed statistical significance of model as evidenced from high value of coefficient of determination (R(2) = 0.9472) and P < 0.05. Viscosity was primarily affected by cellulase concentration, pH and hydrolysis time. Maximum viscosity reduction was obtained when pH, temperature, hydrolysis time and cellulase concentration were 6, 50 °C, 4 h and 1.00 mg/g, respectively. The study is important in optimizing the enzymatic process for hydrolysis of guar gum as potential source of soluble dietary fiber for human health benefits.

Chemical composition analysis of soybean oligosaccharides and its effect on ATPase activities in hyperlipidemic rats

A water-soluble oligosaccharide was isolated from the water extract of soybean, which is widely grown worldwide due to its nutritional benefits of a full range of amino acids and a high protein content. In this study, we analysed chemical composition of soybean oligosaccharides (SBOS) using high performance liquid chromatography (HPLC). The results obtained were compared with the following sugar standards: mannose, galactose, xylose, arabinose, fucose and glucose. Results showed that SBOS was composed of galactose (65.3%), mannose (15.6%), fructose (7.8%) and glucose (8.7%). The pharmacological action of SBOS has been studied in hyperlipidemic rats fed high-fat diet. In hyperlipidemic rats, feeding with SBOS (150 and 300 mg/kg b.w.) exerted a pharmacological effect as assessed by reversal of plasma levels of lactic acid, nitric oxide (NO), vascular endothelial growth factor (VEGF) levels, and heart Na+-K+-ATPase, Ca2+-ATPase and Mg2+-ATPase activities. These results indicated that SBOS may have beneficial effects on the therapy of some heart diseases, such as coronary artery diseases.

Biodegradable hydrogels based on novel photopolymerizable guar gum-methacrylate macromonomers for in situ fabrication of tissue engineering scaffolds

Guar gum (GG) is a non-ionic polysaccharide that is found abundantly in nature and has many properties desirable for biomedical applications. In the present work GG with molecular weights ranging from 74 to 210 kDa was modified with glycidyl methacrylate (GMA) to produce a series of water-soluble photopolymerizable guar gum-methacrylate (GG-MA) macromonomers of different molecular weights. We investigated the effects of molecular weight of GG-MA macromonomers from 102 to 216 kDa and with percent degree of methacrylation (%DM) ranging from 14% to 56% on the properties of GG-MA hydrogels. GG-MA hydrogels exhibited a three-dimensional open cell microstructure with an average pore size ranging from approximately 10 to 55 microm and an average pore density of from approximately 2.4 x 10(6) to 8.6 x 10(7) pores cm(-3). The hydrogels exhibited equilibrium swelling ratios ranging from approximately 22% to 63%. The degree of in vitro enzymatic biodegradation of the hydrogels decreased linearly with increasing gel content and the degree of methacrylation of the respective macromonomers. The human endothelial cell line EA.hy926 was photo-encapsulated in the GG-MA hydrogels. Cells remained viable at low macromonomer concentrations, but cell viability decreased sequentially as the macromonomer concentration increased. GG-MA hydrogels with a 0.05 wt.% GG-MA macromonomer concentration revealed excellent endothelial cell proliferation, similar to that of the Matrigel control.