Physicochemical characterization of the anatomical structures of teosinte (Zea mays subsp. mexicana) covered caryopses

Abstract

Teosinte is the wild ancestor of maize and is used as a study model in evolutionary biology. Information about the physicochemical properties of teosinte caryopses is scarce. Therefore, the aim of this study was to determine the physical properties and chemical composition of teosinte (Zea mays subsp. mexicana, race Chalco) covered caryopses per anatomical structure. Covered caryopses were dissected into cupule, outer glume, and endosperm-germ prior to analysis. Covered caryopses showed a thousand kernel weight, test weight, and flotation index values of 116.4 g, 82.3 kg/hL, and 13.3%, respectively. Chalco teosinte covered caryopses contained protein, fat, dietary fiber, and total starch contents of 7.8%, 2.8%, 54.9%, and 39.2% (dw), respectively. The endosperm-germ fraction accounted for 41% of the covered caryopsis weight and showed high protein and fat contents. It contained 86% and 87% of the total protein and fat contents of covered caryopses. Low total and resistant starch contents were detected in the endosperm-germ fraction. High contents of insoluble dietary fiber were detected in the cupule and outer glume, contributing to the high total dietary fiber content present in covered caryopses. This research is the most recent update on the chemical composition of the anatomical structures comprising teosinte covered caryopses.