Authors: Kayode O. Adebowalea, T. Adeniyi Afolabib, B. Iromidayo Olu-Owolabia
ScienceDirect
Abstract
Sword bean (Canavalia gladiata) starch was chemically modified by acetylation with acetic anhydride and oxidation with sodium hypochlorite. Functional, retrogradation and physicochemical properties of native, acetylated and oxidized starches were compared.
SEM revealed that the starches consisted of smooth ellipsoids, with slight indentations at the centre, and that modification caused rupture of some (<10%) of the granules. Acetylation increased water binding capacity of the starch, as did oxidation, but to a lesser extent. Solubility and swelling power of all starches increased with temp. Analysis of pasting properties indicated that the starches were Type C, with restricted swelling, which is typical of legume starches. Acetylation increased starch viscosity, whereas oxidation reduced it. Modification reduced gelatinization temp. (onset, peak and conclusion) and increased gelatinization enthalpy. Oil and water absorption capacities of the starches were in the ranges 2.9–3.6 and 2.2–2.7 g/g, respectively.