Theobroma grandiflorum (Willd. ex Spreng.) Schum., the
cupuaçu-tree:
additional use option and agro-ecology
The cupuaçu tree, Theobroma grandiflorum (Willd. ex Spreng.)
Schum., is native in the south-east of Pará, Brazil, where it represents a constituent of
the medium stratum of the terra-firme rain forest. Its considerably big fruits (1-2 kg
fresh weight) consist of a lignified husk encasing 20-45 seeds which are surrounded by a
very aromatic pulp, which constitutes about 35-45 % of the fruit's fresh weight. The
cupuaçu tree can be found throughout the Amazon region as part of spontaneous vegetations
on non-inundated areas, particularly near existing or former settlements. The relatively
high market value of the fruit pulp (2 - 4 US$ per kg), which is
used for the production of juice, ice-cream, yoghurts, and other fresh products, makes the
cultivation of cupuaçu-trees more and more attractive. Furthermore the close relationship
to the cocoa-tree (Theobroma cacao L.) give rise to the presumption
that in addition to pulp production the seeds of T. grandiflorum (ca.
20 % of fresh weight) could be used for manufacturing chocolate-like foodstuffs. This
additional use option would reveal the advantage of producing a storable ware which would
supply a separate market. However, attempts to commercialize a type of chocolate-wares
made from cupuaçu-seeds failed so far, probably due to the unsatisfactory and hardly
reproducible quality of the product. Our research on cupuaçu consists of two aspects:
The potential use of the seeds
We are studying the seed inherent factors determining the aroma
potential of T. grandiflorum in collaboration with the CPAA/EMBRAPA, Manaus, and
under the guidance of the cocoa-specialist Prof. Dr. B. Biehl (Technical University
Braunschweig). The crucial factors for the aroma generation are the characteristics of the
storage proteins and the pattern of their degradation by proteolytic enzymes in the course
of fermentation. We investigate also changes in the ultrastructure of the cotyledonous
cells, which seem to be decisive for a sound proteolysis leading to aroma precursors. An overview of our first results has recently been published (Reisdorff, C., Rohsius, C., Claret de Souza, A.d.G., Gasparotto, L., Lieberei, R., 2004: Comparative study on the proteolytic activities and storage globulins in seeds of Theobroma grandiflorum (Willd ex Spreng) Schum and Theobroma bicolor Humb Bonpl, in relation to their potential to generate chocolate-like aroma. Journal of the Science of Food & Agriculture 84/7, 693700.)
Agro-ecology
The recently expanding cultivation of T. grandiflorum is guided
by breeding programs evaluating agronomic characteristics of strains and clones of primary
selected plant material. In addition to these efforts, which mainly focus production
parameters under standard conditions, it is necessary to line out a type of an
agro-ecological profile of the plant, and to identify the most advantageous conditions for
its cultivation. Thus, we are monitoring the development and production of 750 cupuaçu
trees in different mixed cultivation systems and a monoculture on an experimental site
near Manaus, Brazil. Beside the effect of planting systems and management measures we
evaluate to which extent varying topographic and micro-climatic conditions influence the
development and productivity of cupuaçu plants.
These studies are part of the project "Recultivation of
Degraded Areas into Polyculture Areas" (project ENV23/2) which is conducted
within the frame of the SHIFT-program (Studies on Human Impact on Forests and Floodplains in the Tropics), a
Brazilian-German cooperation supported by the BMBF, Germany, and the CNPq and IBAMA,
Brazil.
