Physico‐chemical Properties of Oil Palm Trunk Starch

Physicochemical properties of the starch extracted from oil palm trunk (Elaeis guineensis Jacq.) were investigated. The extraction of starch was achieved by using an aqueous solution containing 0.5% sodium metabisulphite. Moisture content protein, lipid, ash and total amylose content were found to be 11.8, 0.9, 0.3, 1.03 and 19.5%, respectively. Measurement of starch granule size with a Coulter Counter revealed a bimodal distribution, with an average of 14.5 μm. Further studies on cross-section of oil palm trunk indicated that the starch granules were located intracellular. Examination of starch granules under a Scanning Electron Microscope exhibited both an oval and an elliptical shape with a truncated end. An X-ray diffraction investigation of this starch exhibited an A-type X-ray pattern. Percentage of swelling power and solubility determined at 90°C were found to be 33.1 and 30.8, respectively. Gelatinisation temperature obtained by Differential Scanning Calorimetry (DSC) ranged from 52.4°C to 72.1°C. with a peak melting temperature of 62.9 °C. The flow behaviour characteristics of oil palm trunk starch is pseudoplastic and viscosity depends on starch concentration, temperature and shear rate.