Effect of Different Drying Methods on Milling, Pasting and Texture Properties of Rice

Abstract

This study examined the effect drying methods on physicochemical milling and pasting properties of rice (Sakha 101). Rice samples were subjectingafter harvesting directly to four different drying methods as following  raw or reference rice is fresh rice, whichwas drying by ambient air ventilation,sun drying, and hot air drying and roasting drying.The results showed that,control sample had the highest significant percentages of unbroken grains and head rice and the lowest broken grains, followed by sun drying sample followed by sample dried with hot air and finally sample treated with roasting drying. Control sample had the highest significant percentages of milling recovery (83.66%), followed by sun drying sample (82.08%) followed sample treated with roasting drying (81.85%) and finally sample dried with hot air (80.33%). Ambient air drying (control) sample had the highest pasting temperature (93.86 °C) , final viscosity (128.14RVU)and setback viscosity (79.64 RVU), but it gained the lowest breakdown viscosity(15.32) and peak viscosity (63.24 RVU  ) ,while roasting drying sample showed  the lowest pasting temperature (92.44 °C) , final viscosity (122.54  RVU  )and setback viscosity (70.36 RVU), but it gained the highest breakdown viscosity(19.54) and peak viscosity (66.58 RVU  ) . Reductions in the hardness of the dried rice grains were observing in the roasting and hot air drying samples, respectively when compared to samples dried at ambient and sun drying. While for adhesiveness, reductions were observing for the dry grains at ambient and sun drying.