Abstract
The relative average degree of channelization (RADC) of starch granules may be important for identifying starch genotypes that are well-suited for chemical modification. The objective was to investigate development of a screening method for estimating RADC amongst starches of five maize inbred lines. Manual counting of channels within merbromin-stained starch granules visualized by confocal laser scanning microscopy was established as a RADC reference method, grouping starches of the five lines into high (Oh43), intermediate (A188, W22), and low (B73, W23) RADC categories. Total specific surface area values obtained by nitrogen gas adsorption were strongly correlated (0.92) to reference RADC rankings of the starch lines. However, fluorescent intensities of starch granules modified in a surface reaction with a fluorescent probe did not correlate with the reference rankings. Nitrogen gas adsorption represents a potential screening technique for estimating RADC, though furtdher refinement of the method is yet needed.