Abstract

Steam-flaked corn samples were used in a series of experiments to determine if refractive index could be used as a rapid, inexpensive method to predict starch availability. Results were best when samples were incubated for 15 min with 500 to 600 active units of enzyme/gm of grain prior to measuring on a hand-held refractometer. Correlations to starch availability determined from gas production by a commercial lab were R=.64 for whole flakes and R=.79 when samples were ground. Samples of corn flaked to different densities produced estimates of solubility similar to an in situ dry matter disappearance assay (R2 = .84, P<.01). Furthermore, refractive index yielded estimates of starch solubility that were well related to a commercial lab's measures of glucose release for samples of flaked corn that were stored for 0 to 48 hours subsequent to flaking.

Keywords: Cattlemen's Day, 2000, Kansas Agricultural Experiment Station contribution, no. 00-287-S, Report of progress (Kansas State University. Agricultural Experiment Station and Cooperative Extension Service), 850, Beef, Starch availability, Steam-flaked corn, Refractive index

How to Cite:

Sindt, J., Montgomery, S. P., Farran, T. & Drouillard, J. S., (2000) “Refractive index: a rapid method for determination of starch availability in grains”, Kansas Agricultural Experiment Station Research Reports 1(1), 62-64. doi: https://doi.org/10.4148/2378-5977.1801