Effect of Different Milling Methods on the Physicochemical Properties of Rice Flour and the Qualities of Fresh Rice Noodles

Abstract

To reveal the effects of milling methods on the physicochemical properties of rice flour and the qualities of fresh rice noodles, the rice was treated by dry, semi-dry, and wet milling methods and the resultant products were utilized to produce fresh rice noodles. The basic chemical components, the damaged starch rate, the size distribution, the morphology, the solubility and swelling power, and the pasting properties of the rice flour, as well as the texture, cooking, and sensory qualities of fresh rice noodles, were investigated. The obtained results suggested that the rice flour produced by drying methods with a 300 mesh had the highest damaged starch rate (17.55%) and solubility, smallest particle size, peak viscosity, final viscosity, and setback viscosity. By contrast, the rice flour produced from wet milling methods showed the lowest damaged starch rate (2.87%) and solubility, and the highest peak viscosity, final viscosity, and setback viscosity. Increasing the moisture content during the semi-dry milling treatment, the damaged starch rate of the rice flour decreased from 4.49% to 3.55%, and similar trend was observed for particle size distribution and solubility. Scanning electron microscopy suggested that the lower damaged starch rate, the more intact structure of the rice flour. The fresh rice noodles made from wet milling flour showed the best cooking qualities, and the cooking qualities of semi-dry milled flour-made and semi-soaking milled flour-made fresh noodles were close to those of wet milled flour-made fresh rice noodles while the rice flour produced from dry milled method was not suitable for making fresh rice noodles. The semi-dry and semi-soaking milled rice flour can replace the wet milled rice flour for the preparation of rice noodles during the practical production process. The findings in this study may assist the revolution for the traditional production of rice noodles.

Keywords

• rice flour
• physicochemical properties
• damaged starch rate
• fresh rice noodles
• cooking qualities