Native Fruit Tree Improvement in Amazonia: An Overview - Indigenous Fruit Trees in the Tropics: Domestication, Utilization and Commercialization - page 107

mandated implicitly or explicitly in international treaties, serving as a best
practice alternative to biopiracy (Simons and Leakey, 2004). These benefits
include, but are not restricted to, access to germplasm for own use or for sale.
Other potential benefits include opportunities for joint and mutual learning,
capacity and skill-building, institutional development (formal and farmer
institutions) and policy development (Christinck et al ., 2005).
Participatory improvement also has some possible disadvantages with
respect to the conventional approach. The logistical difficulties and, in some
cases, the costs of maintaining participatory field experiments may be
considerable. Although farmers may themselves meet part of the cost through
their own labour, distances between experiments can be considerable, and the
difficulty of regular monitoring can lead to problems in trial maintenance and
protection. Second, close involvement of farmers in research planning and
execution requires the effective deployment of skills and techniques that may
be unfamiliar to many researchers. Thus, the approach is difficult to implement
in situations where professionals with the necessary skills in participatory
research are absent, both in the research community and in the extension
services. Conventional improvement done well may be better than
participatory research done poorly or in a 'token' way.
6.3.1 An example of participatory and conventional improvement: camu-camu
Myrciaria dubia (H.B.K.) McVaugh, Myrtaceae, called camu-camu in Peru and
caçari or river guava in Brazil, is a shrub that may attain 4 m in height and be
generally abundantly branched from the base, forming an open vase-shaped
crown (Pinedo et al ., 2001). The fruit is a round berry with a smooth, somewhat
shiny skin, dark red to almost black purple when ripe; the colour is due to a
mixture of anthocyanins. Fruit weight varies from 3 to 20 g, with an average of
7 g; diameter varies from 2 to 4 cm. The fruit contains 1-4 flattened kidney-
shaped seeds that are 8-11 mm wide. The average fruit has 51% white to nearly
translucent, slightly fibrous, juicy pulp, although this percentage varies
depending upon fruit size and number of seeds; the average fruit also has 20%
skin and 29% seeds (Pinedo et al ., 2001); the use of mechanical separators
leaves only 30% skin and seeds. Because the fruit skin is thin and coloured, this
is generally processed with the pulp to obtain a pleasant reddish purple colour.
The chemical composition of the skin-pulp mixture has been reported (Calzada,
1980). Recent prospecting has identified fruit with enormous variation in
ascorbic acid content: 0.8-6.1 g in 100 g skin-pulp (Yuyama et al ., 2002).
Camu-camu has attracted considerable attention because of its high
ascorbic acid content, especially as this is an important antioxidant (Rodrigues
et al ., 2006). Initially, numerous food products based on the fruit were
developed, such as juices, nectars and yogurts, and frozen pulp is also
commercialized. Currently numerous healthcare and personal hygiene products
have also been made available, including skin creams, shampoos and mascara,
as well as capsules and powders made from dehydrated skin (as this is richest
in ascorbic acid and anthocyanins).