Physicochemical Properties of Mungbean Starch

Abstract

Starch was isolated from mungbean (Vigna radiata L. Wilczek) seeds and its chemical and physicochemical properties were determined. The starch had 33.19% of amylose and an A-type X-ray diffraction pattern (major reflections at 2.THETA.=15, 17 and 23.DEG.). The amylograph patterns of 5 and 8% mungbean starch pastes highly depended on concentration. Differential scanning calorimetry showed endotherms at 59-69-75.DEG.C.(To, Tp, Tc) and enthalpy of 6.11J/g. The rheological parameters G' (storage modulus), G" (loss modulus) and G* (complex modulus) were higher at 10% than at 5% concentration, but tan .DELTA. (G"/G') was almost the same. Gel permeation chromatography of acid resistant residues showed peaks with degrees of polymerization(DP) of 25 and 17 before and after treatment with isoamylase, respectively.