A Study of Factors Affecting Amylose Content of Sorghum Determined by an Automated Method

Abstract Several factors affecting the amylose content of sorghum, as determined by an automated iodine‐blue complex method, were evaluated. Isolation of starch reduced the optimum solubilization time of the endosperm starch by 36 h. Amylose as % of isolated starch was significantly greater than amylose as % in the endosperm. However, amylose as % of starch in endosperm (“apparent” amylose content) was highly significantly correlated (r = 0.79) with amylose as % of isolated starch (“true” amylose content) that it could be used for screening sorghum in a breeding program. Pericarp and testa colors significantly affected the measurable amylose of unpearled sorghum flour. The environment of growth and maturation of the grain also affected the amylose content of sorghum.