MICROESTRUCTURAL FEATURES AND POSSIBLE END USES OF MAIZE ACCORDING TO ITS GEOGRAPHIC ORIGIN

Abstract

Most microstructural studies of maize have been starch industry oriented and only a few have been related to food or tortilla quality. The relation between kernel microstructure and functional properties of Latin American maize (Zea mays L.) races and their possible uses in relation to their geographical origin was studied. Seventy-one races were analyzed for microstructural features such as endosperm cell bodies compactation and starch granule size and morphology. The final use of its grain was related to the microstructure. Highly compacted kernels, with small (< 12 µm), hexagonal-shaped starch granules surrounded by a dense protein matrix, were more frequent in races suited for popcorn. As compactness and pericarp thickness (75 µm) decreased the size of starch granules increased, and that race became more suitable for snacks, flour, tortillas, “pozole” and “atole”. The races appropriate for making “pozole” and “atole” had spherical starch granules and thinner pericarp (32 µm). The races appropriate for making tortillas and nixtamalized flour evidenced both kinds of morphology due to the nearly equal proportions of hard and soft endosperm in the kernels. Races from México and South America showed wide variation in the end uses studied, while those from Central America and the Caribbean were found to be appropriate only for tortillas and snacks.