Effects of Saccharose Substitutes on Physicochemical Properties and Free Radical Generation in Oxidized Potato Starch

Abstract

This study aimed at investigating the effects of saccharose and its substitutes (sorbitol, acesulphame, aspartame) added to potato starch oxidized with sodium chlorate (I) on the physicochemical properties of starch and generation of free radicals at both 150 and 230°C. Oxidized starch with saccharose and its substitutes were analyzed by thermodynamic characterization of pasting, rheological properties, and susceptibility to degradation of 2% pastes. Moreover, a number of generated thermally free radicals in investigated samples was determined by quantitative electron paramagnetic resonance spectroscopy measurements. Saccharose and sorbitol increased considerably the onset temperature of transition (T0) and the peak temperature of transistion (Tp) as determined by differential scanning calorimetry. Among the sweeteners, only aspartame influenced the characteristic viscosities of the starch-sweetener-water systems, reducing the thermal stability of the obtained pastes. Acesulphame K and aspartame caused the largest increase in the susceptibility to retrogradation of 2% pastes of oxidized potato starch. In the presence of sorbitol, the number of radicals generated thermally in starch decreased. This effect, found by quantitative electron paramagnetic resonance spectroscopy measurements, indicates effective interaction of hydroxyl groups of the sorbitol molecule with starch matrix, leading to the stabilization of the starch structure.