Physical, chemical and microstructural characteristics of flint and dent corn grown in the U.S.A. and Canada

Abstract

The physical, chemical and microstructural properties of corn from three production areas-- U.S.A., Ontario and Alberta, were compared and discussed relevant to distilling. The major chemical constituent in corn was starch. Alberta corn was found to have less starch compared to corn from U.S.A. or Ontario. Sucrose, the main sugar, did not vary consistently and was low in content for all areas. When the structural carbohydrates were compared, the pentosan content and the glucan associated with fiber were higher in Alberta corn compared to corn from U.S.A. or Ontario. This data supported the observation that Alberta corn generally yields less alcohol. Based on the physical characteristics of the kernel, Alberta corn had a larger germ and a smaller endosperm, indicative of a higher lipid content and a lower starch content respectively, compared to corn from U.S.A. or Ontario. Examination of the endosperm by scanning electron microscopy revealed that in Alberta corn, the endosperm was almost completely horny, typical of flint corn. In U.S.A. and Ontario corn, it consisted largely of floury endosperm, typical of dent corn. The starch granules in corn endosperm were found to have hollow cores, which were larger in granules from floury endosperm. When starch was prepared from selected corn samples and the properties measured, viscoamylography indicated that Alberta starch had slighty higher viscosities compared to starch from U.S.A. or Ontario corn.