Relationship between structural and biohemical characteristics and texture of corn grains.

• Main Author: PEREIRA, R. C.
• Publication Date: 2008
• Other Authors: DAVIDE, L. C., PEDROZO, C. A., CARNEIRO, N. P., SOUZA, I. R. P., PAIVA, E.
• Format: Article
• Language: eng
• Source: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Download full: http://www.alice.cnptia.embrapa.br/alice/handle/doc/491589
• topic: endosperm; corn; protein bodies; starch granules; zein

The texture of corn grains is a fundamental characteristic for the industry as well as for grain producers and processors. To further understand the mechanisms involved in grain hardness, contrasting com cultivars for grain hardness and protein quality were evaluated. The cultivars were Cateto L237/67 (hard endosperm and low protein value), QPM BR 451 (semi-hard endosperm and high protein value); Bolivia-2 (floury endosperm and low protein value), and Opaque-2 (floury endosperm and high protein value). Evaluations were carried out at 10, 20, 30, 40, 50, and 60 days after pollination in developing com grains and in the mature grain. In developing grains, evaluation consisted in the determination of the area, percentage of starch granules, distribution of starch granules, and protein bodies in the endosperm. In mature com grains, the parameters evaluated were: density, percentage oftotal proteins, levels of Iysine and tryptophan, and banding pattem of zeins. The results indicate that the higher physical resistance of com grains from the cultivars analyzed is influenced by the high percentage oftotal pro-teins, high synthesis of 27-kDa zeins, presence of protein bodies, and perfect organization of starch granules in the endosperm, inde-pendent of their sizes.