Chain Length Distribution of Amylopectin and Physicochemical Properties of Starch in Myanmar Rice Cultivars

Abstract

Three different types of amylopectin: long chain length of amylopectin (L-type), medium chain length of amylopectin (M-type), and short chain length of amylopectin (S-type) were classified in 16 rice cultivars (3 for L-type, 6 for M-type, and 7 for S-type amylopectin) based on chain length distribution of amylopectin by fluorophore-assisted carbohydrate electrophoresis through capillary electrophoresis. Frequency distribution of amylopectin chain ratio and short chain ratio supported three types of amylopectin. Ta Soke Pwa and Thet Nu Saba Net Pyan had high values of transition temperatures in a range from (70.7, 74.0, and 77.6°C) to (71.4, 75.0, and 78.8°C) in differential scanning calorimeter analysis. Alkali spreading values and starch gelatinization characteristics in 4 M urea solution showed the association between chain length distributions of amylopectin in Myanmar rice cultivars. A simple linear regression in Myanmar rice cultivars was observed for fa, fb1, amylopectin chain ratio, and short chain ratio with alkali spreading values, with R2 values of 0.68, 0.84, 0.84, and 0.81, respectively.