Use of ozonation, a green oxidation method, in the modification of corn starch-gum arabic suspensions: thermal, rheological, functional and antioxidant properties

Effect of various ozonation durations (i.e., 15, 30, and 60 min) on selected properties of gum arabic with 0.5% concentration (db), corn starch (S) and corn starch-gum arabic dispersion (GAS) were investigated. Ozonation generally caused significant decrease in viscosity of samples (P < 0.05), providing potential ease of use in industry. Peak temperature of GAS was increased after 60 min ozonation (P < 0.05), as measured by differential scanning calorimeter. The pH values decreased after for each ozonation period (15, 30 and 60 min) (pH 5.0 to pH 2.50), due to possible hydroxyl oxidation by ozonation, which was linked to increased formation of carbonyl and carboxyl groups. It was observed that ozonation resulted in increased water solubility index whereas a decrease was observed in water adsorption index. Ozonation increased the quantity of reducing sugars (19.3%), phenolic compound concentrations (24.0%) and radical scavenging activity (48.0%) compared to control samples after 60 min ozonation. This study suggests that ozonation could be used to oxidize GAS dispersions by an environment friendly approach.