Ozone gas affects physical and chemical properties of wheat (Triticum aestivum L.) starch

In this experiment, bread wheat flour and isolated wheat starch were treated with ozone gas (1,500 mg/kg at 2.5 L/min) for 45 min and 30 min, respectively. Starch was isolated from treated flour. Ozone treated starch and starch isolated from ozone treated flour had similar chemical and physical properties. Chemical analysis of starch isolates indicated depolymerization of high molecular weight amylopectins; with a subsequent increase in low molecular weight starch polymers as a result of starch hydrolysis. Ozone treatment resulted in elevated levels of carboxylic groups and decreased total carbohydrate content in amylopectin fractions. 1H NMR results indicated formation of a keto group [(1→4)-3 keto] at the H-2 terminal (proton at C-2 position) and β-glucuronic acid at the H-1 terminal (proton at C-1 position). DSC transition temperatures and change in enthalpy were not affected by ozone treatment. Increased swelling power and RVA breakdown were observed in starch from ozone treated samples.