Effect of ozonation on some properties of corn starch-gum mixtures

This thesis includes the investigation of rheological, thermal and functional properties of gum arabic, guar gum and corn starch as a result of ozonation. The study consists of two main parts. In first part, gum arabic (GA) with 6% (w/w) concentration was ozonated at different times (5, 30 and 60 min) and its rheological, thermal and functional properties were investigated. In second part, gum arabic-corn starch and guar gum-corn starch suspensions were prepared. For preparation of suspensions, corn starch was mixed with distilled water at ratio of 1:15 (w/w), gum arabic (GA) and guar gum (GG) 0.5% (dry matter) were added to starch suspensions. Prepared guar gum- corn starch (GGS) suspensions (5, 10, 15, 30 and 60 min) and gum arabic-corn starch (GAS) suspensions (5, 30 and 60 min) were ozonized and the rheological, thermal and functional properties were investigated. Result of ozonation, viscosity of the samples decreased and exothermic peak temperatures decreased with increasing ozonation time in all samples compared to the control samples. The pH values of the samples decreased with increasing carbonyl and carboxyl groups. With ozonation, the water solubility index of the samples increased and the water adsorption index decreased. In addition, ozonation process increased the phenolic contents and antioxidant activities of the samples. As a result of this study, with the effect of GA, GG, GGS and GAS ozonation, the rheological, thermal and functional properties of the samples were improved and the samples were made easier to use in the industrial sense. With the ozonation process, a method that is cheap, easy and can be applied in a short time, has a high effective and environmentally friendly has been applied.