Abstract: The differences in physicochemical properties between oxidized and native wheat starch were analyzed as well as the effect of addition of oxidized wheat starch on the quality of fresh noodles. The oxidized starch was prepared with H2O2 by 4 h reaction at 50 ℃. The results indicated that the surface and internal structure of oxidized starch was damaged. Oxidized starch granules were adhered to each other in aqueous suspension. Compared with native starch, the crystal type of oxidized starch was unchanged, the lipid-binding ability was increased, the content of amylose decreased slightly, the swelling power and water-holding capacity significantly decreased (P < 0.05), and the solubility significantly increased (P < 0.01). No significant differences in wet gluten content, gluten index and dry gluten content were demonstrated between mixtures of native and oxidized starch with flour at a ratio of 1:4. The peak viscosity, minimum viscosity and final viscosity of flour were significantly reduced with the addition of oxidized starch (P < 0.01). The proportion of strongly bound water in fresh noodles with oxidized starch was decreased, and the proportion of weakly bound water was increased. During heating, the storage modulus and loss modulus of noodles with oxidized starch were lower than those of the control sample.

Key words: oxidized starch, physicochemical properties, noodle, water distribution, thermodynamic properties