Cereal Chem 72:436-442  |  VIEW ARTICLE

Identification of Starch from Various Maize Endosperm Mutants via Ghost Structures.

M. Obanni and J. N. BeMiller. Copyright 1995 by the American Association of Cereal Chemists, Inc. 

Commercial maize and waxy maize starches and starches from six single endosperm mutants, eight double mutant combinations, and one triple mutant were examined by a new, simple, rapid, inexpensive technique that requires only a small amount of starch. This technique can be applied in a way that is nondestructive of the germ and the majority of the endosperm of a kernel. The technique involves cooking without shear, staining with iodine, and examining by light microscopy. Each of the 17 starches examined exhibited repeatable unique cooking behaviors and dilute paste compositions that allowed each to be distinguished clearly from the others. Differences found were in the number and shapes of unswollen or only slightly swollen granules; the number, shapes, stained color intensities, and sizes (degrees of swelling) of swollen granules; the number, shapes, and stained colors and intensities of granule ghosts (remnants); and the number of "clusters" present. Clusters, which are reported for the first time, are groups of small units (4-12) with a dark blue center, sometimes surrounded by an envelope. It is suggested that this method has great potential as a screening tool for plant breeders in comparing the behaviors of genetically modified starches to those of chemically modified starches.