An insight into the impact of microwave treatment on the morphology, functionality, and resistant starch content from conventional rice landraces

The effect of the microwave treatment on the physicochemical, functional, morphological, and resistant starch content of the microwave-treated starch from five conventional landraces was evaluated in this study. The microwave treatment (MWT) substantially enhanced the amylose concentration, functional attributes, and resistant starch content. The microwave-treated Thanga samba sample exhibited the highest amylose content of 27.54%. The scanning electron microscopic images of the modified starches depicted slightly rough surfaces compared to the native starches. The improved amylose content influenced the crystallinity, water absorption capacity, swelling power, and resistant starch content of the microwave-treated starches. The higher relative crystallinity of 34.30% was recorded for the native Sivan samba in contrast to other starch samples. The resistant starch content of the modified samples varied from 10.67 to 12.63 g/100 g. The molecular breakdown ascribed to the MWT increased the granular size of the starch particles. The peak temperature and gelatinization enthalpy of the microwave-treated starches reduced attributing to the molecular reassociation. The enhancement of water and oil absorption capacity and the acceleration of the functional utility of starch have been observed following modification. These findings have significant implications for the application of starch in the food processing industry. These functionalized starches can be recommended for biodegradable film applications and targeted delivery in the field of nutraceuticals.