Modification of poovan banana (<i>Musa </i><scp>AAB</scp>) starch by γ‐irradiation: effect on <i>in vitro</i> digestibility, molecular structure and physico‐chemical properties

Abstract

Summary This study focussed at evaluating the effect of gamma irradiation on the in vitro digestibility, molecular structure and physico‐chemical properties of poovan banana ( Musa AAB ) starch using γ‐rays from a 60 Co source at different doses with a dose rate of 2 kG y h −1 . Physico‐chemical properties varied significantly and exhibited strong dose‐dependent relationship. Escalating irradiation leads to decrease in amylose content, pH , swelling power of the starch granules and syneresis of the gelatinised starch, while the same led to an increase in carboxyl content, in vitro digestibility, solubility and water absorption capacity of the starch granules. The results revealed that peak, hold, final and setback viscosities were significantly reduced. X‐ray diffraction pattern remained the same upon irradiation but a decrease in relative crystallinity was observed with increasing irradiation dose. Gelatinisation temperature and enthalpy decreased significantly when the increasing the dose of gamma irradiation.