Effect of low dose γ-irradiation on the structural and functional properties, and in vitro digestibility of ultrasonicated stem starch from Corypha umbraculifera L.
Basheer Aaliya, Kappat Valiyapeediyekkal Sunooj, Muhammed Navaf, Plachikkattu Parambil Akhila, Cherakkathodi Sudheesh, Sarasan Sabu, Abhilash Sasidharan, Shabir Ahmad Mir, Johnsy George, Amin Mousavi Khaneghah
Abstract
In the present study, non-conventional talipot starch was subjected to single and dual modifications using two non-thermal techniques; ultrasonication and γ-irradiation (1 kGy and 10 kGy). Free radical-mediated low dose γ-irradiation made remarkable changes in the morphological, physicochemical, and functional properties of ultrasonicated talipot starches compared to single modifications. Dual (ultrasonication+γ-irradiation) modification created deep grooves, reduced relative crystallinity and peak intensity of OH and CH2 groups by cavitation and radiolysis. Compared to ultrasonicated and γ-irradiated starches, dual-modified starches showed significantly reduced (p ≤ 0.05) pH, amylose content, and swelling power, and improved storage stability by lowering the retrogradation tendency. The in vitro digestibility of dual-modified talipot starches was increased by the enhanced action of digestive enzymes with starch. The gelatinization, pasting, and rheological properties significantly decreased (p ≤ 0.05) with the increasing dose of γ-irradiation in dual-modified talipot starches and represented soft gel possessing shear-thinning stability.