Caracterização estrutural e quimica do tecido de reserva das sementes de Theobroma cacao, Theobroma obovatum e Theobroma microcarpum

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Lately,the wildTheobroma species have called attention of the biotechnology field researchers, as a possible bank of useful genetic resources to the improvement of cocoa (Theobroma cacao) as a plant and raw material for chocolate. Attributes such as lipid composition, protein profile,polyphenol content and response to the chocolate process have been searched in seeds of the wildspecies. The aim of this study was to contribute to the knowledge of the wild Theobroma species. The cotiledonary tissue s morphology and ultrastructure and the chemical composition of Theobroma obovatum s and Theobroma microcarpum s mature seeds were investigated and compared to T. cacao. The fixed material was included in resin GMA for the histochemistry methods and included in Epoxi resin for transmission electron microscopy (TEM).The mature seeds were also submitted to the scanning electron microscopy (SEM) techniques and chemical compositon analysis. We could observe a clear similarity between T. obovatum and T. cacao as well as the diversity in the genus when compared to T. microcarpum. It can be noticed in T. obovatum the same pattem of storage compounds accumulation and cotiledona Y tissue s morphology observed in T. cacao, the protein storage vacuoles (PSVs) occupy the central portion of the cell or they are squeezed between the lipid bodies. In T. microcarpum the PSVs occupy the spaces among the large starch grains. Conceming these species, T. cacao has the major phenoliccell expression, followed by T. obovatum. The phenolic cells usually come along with the vascular bundle or can be dispersed through the parenchyma, as gathered or isolated cells. The chemical composition of T. obovatum seeds (=60% of lipids,25% of proteins, 10% of carbohydrates and 5% of total phenols) approaches to the values found in T. cacao seeds (=49% of lipids,27% of proteins, 18% of carbohydrates and 8% of total phenols) and both of them are different from the values found in T. microcarpumseeds (= 6% of lipids, 13% of proteins, 75% of carbohydrates and 2.7% of total phenols) which accumulate starch as the main storage compound

ASSUNTO(S)

citoquimica sementes banco de sementes - reservas cupuaçu

ACESSO AO ARTIGO

Documentos Relacionados