1. Introduction
Rice noodle is one of the most popular noodles in Asia. Rice noodle is made by mixing rice flour with a high amylose content (amylose content > 25%) with water (Hormdok & Noomhorm, 2007). Then, the rice flour slurry is steamed to obtain the fresh rice noodle sheet. The fresh noodle sheet is cut into strips. Fresh rice noodle has a high moisture content, so it is easily perishable. In order to extend its shelf-life, fresh rice noodle is dried to the final moisture content at 10–12%. The process of drying rice noodle is divided into three steps: pre-drying, ageing, and final-drying. In the pre-drying step, some water is removed, so the moisture content of noodle is about 34%. Then, the noodle sheet is aged at room temperature for 12–24 h. Finally, the noodle sheets are cut into strips and dried to the final moisture content at 10–12%. The consumption of rice noodle, which is a gluten-free product, has increased recently due to the spreading of celiac disease over the world (Gallagher, Gormley, & Arendt, 2004). Good rice noodle should be white in color and have a soft texture. However, most of the dried rice noodle has a hard texture after cooking (rehydration) which is an inferior point. Hence, many manufacturers add salt into the dried rice noodle to prevent the hardness and increase the elasticity of the cooked rice noodle. However, there is no scientific report on the effect of salt on the texture of rice noodle.