Development of a novel formula for estimating the amylose content of starch usingjaponicamilled rice flours based on the iodine absorption curve

The apparent amylose content (AAC) is usually measured by an iodine colorimetric method using the starch as a sample. Nevertheless, it is time-consuming and labor-intensive to prepare rice starch. Therefore, we compared two methods, starch method and milled rice flour method. The former AACs were higher than the latter and correlated with pasting properties, physical properties and sensory scores better than the latter. Therefore, we developed a novel formula for estimating the AACs of starches fromjaponicarice cultivars using milled rice flours instead of using rice starch. The correlation coefficients of the new formula were 0.89 for calibration and 0.94 for validation, which showed that this equation can be applied to unknownjaponicarice samples, and will lead to easy, rapid, and accurate iodine method to determine rice AACs using milled rice flours instead of starch.