Abstract
In this work, a novel hydrophilic biopolymer derived from the tubers of Ipomoea batatas was evaluated. Fibre obtained after the separation of starch from the milled tubers was dried at 60 o C and pulverised. A 500 g of this was submerged in enough 3.50 % w/v sodium hypochlorite and kneaded for 10 min, washed severally with distilled water till the pH became neutral. It was submerged in sufficient 96 % v/v ethanol, stirred for 5 min, dried at 60 o C and classified with sieve 60. A 100 g of this was mixed with 250 ml of 3.0 % w/v sodium hydroxide, precipitated with acetone and dried in a desiccator. It was sized with a 250 μm sieve and coded as I-polygel. Its organoleptic, pH, densities, flow parameters, elemental analysis, hydration capacity, swelling index, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), moisture content/adsorption and ash profile were verified. Results show an odourless, fine, tasteless, off-white powder with pH, 6.85 ± 0.12 and mean particle size, 61.62 ± 0.2 μm. It was insoluble in organic solvents but gelled rapidly in cold water (viscosity, 1% w/v ≈ 127cP). Moisture content/adsorption, hydration/swelling index was high. The powder displayed good flowability. It has cellulosic morphology with a melting peak of about 90 o C. Heavy metals such as lead or mercury were not detectable. The general properties of I-polygel show that it is a hydrophilic biopolymer and may serve as a pharmaceutical excipient for possible applications in novel drug delivery systems.
