Title: Determining cereal starch amylose content using a dual wavelength iodine binding 96 well plate assay Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 25, 2013
Publication Date: September 29, 2013
Citation: Wilson, J.D., Kaufman, R.C., Bean, S., Herald, T.J. 2013. Determining cereal starch amylose content using a dual wavelength iodine binding 96 well plate assay. AACC International Annual Meeting. Abstract. 2-P. Technical Abstract: Cereal starch amylose/amylopectin (AM/AP) ratios are critical in functional properties for food and industrial applications. Conventional determination of AM/AP of cereal starches are very time consuming and labor intensive making it very difficult to screen large sample sets. Studying these large data sets is necessary in evaluating breeding samples and studying the impact the environment has on cereal starch development. The objective of this study was to develop a scaled down version of the amylose iodine binding assay (colorimetric) in a 96 well plate single and dual wavelength ( '620nm and '510nm respectively) assay. The standard curve for amylose content was scaled down to work in a 96-well plate format demonstrated by regression equations with R2 values of 0.999 and 0.993 in single and dual wavelength, respectively. The plate methods were applicable over large ranges of amylose contents; high amylose maize starch at 61.7±2.3%, normal maize starch at 25.0±0.6%, and a waxy maize starch at 1.2±0.9%. The method exhibited slightly greater amylose content values than the Megazyme (K-AMYL) method for normal type starches; but is consistent to cuvette scale iodine binding assays. This method was tested on maize, wheat and sorghum starch providing excellent reproducibility.