Effect of Milling Methods on Physicochemical and Pasting Properties of Ayutthaya 1 Rice and Brown Rice Flours

Abstract

The purpose of this research was to study the effects of the dry, wet and mixed milling methods on the physicochemical quality and pasting properties of Ayutthaya 1 rice and brown rice flours. From the comparative experiment of white rice flour and brown rice flour that have been milled in 3 methods: dry milling; wet milling and mixed milling, it was found that the milling method affected its physicochemical properties, with the wet milling method resulting in the highest L* value color (brightness), the lowest b* color value (yellowness), the highest carbohydrate content, and the lowest fat content (p<0.05). As a result, swelling index and water solubility index of rice flour were likely to increase. The mixed- and wet-milled flours had a higher swelling and water solubility indexes than dry milling method. Brown rice flour had a lower swelling index than rice flour. The gelatinization temperature of both rice and brown rice flours milling by all 3 milling methods was no significant difference (p>0.05) in the range of 75.17 – 75.83 ^oC. White rice flour produced by the mixed milling method showed the highest peak viscosity (5,574.67 cP), while wet milled brown rice flour had the highest values of a breakdown, final and setback values (p<0.05, which were 2,927.67, 6,399.00 and 1,853.33 cP, respectively).