Comparative study of UVC irradiation and heat treatment on Fenton-like oxidation of corn starch in a continuous flow system: Performance and greenness

UV irradiation and heat treatment, recognized as environmentally friendly methods, are extensively applied in modifying starch properties. The current work presented Fenton-like oxidation process of corn starch using a blend of H 2 O 2 and CuSO 4 under ultraviolet C (UVC) irradiation (wavelength of 254 nm) and heat exposure (50 °C) within a novel continuous flow system. The parameters of the experimental setup were separately optimized through one-factor-at-a-time and orthogonal design. The optimal conditions for both treatments included the pH value of 5.0 for starch slurry, irradiation duration of 60 min along with oxidant and catalyst concentrations of 2 % and 0.5 %, respectively. Under the optimized conditions, the effect of using H 2 O 2 /Cu 2+ or H 2 O 2 alone in combination with UVC and heat on physicochemical and structural attributes of native starch was compared. The higher oxidation degree was obtained for treatments of H 2 O 2 /Cu 2+ /Heat (0.461 %) and H 2 O 2 /Cu 2+ /UVC (0.378 %) compared to the other treatments. The findings showed that thermal treatment exerted a more pronounced influence on properties of oxidized starches compared to UV-C irradiation. Eco-scale methodology verified the green nature of the designed treatments for the starch oxidation. • Effects of heat and UVC on Fenton-like oxidation of corn starch were compared. • A new continuous flow reactor was designed for applying the designed modifications. • High oxidation degree of the starch was obtained by both treatments. • Eco-Scale evaluation confirmed the greenness of the modifications.