Bacuri

Related species
Description and phenology
Distribution, abundance and ecology
Uses and economic potential
Collection methods and yields
Propagation and cultivation methods
Research contacts
Commercial contacts

Charles R. Clement

Family: Guttiferae

Species: Platonia insignis Martius

Synonym: P. esculenta (Arruda de Camara) Rickett & Stafleu

Common names: Bacuri, bacury, bacuryuba, ibacopary, ibacury, pacoury, grande pacuru, ubacury (Brazil); bacury-guazú (Paraguay); pakooru (Guyana); pacouri (French Guiana).

Related species

Bacuri is the only species in its genus. A closely related genus, Rheedia, has several interestingly flavored fruits that have the same general fruit structure, although they are always smaller. See FAO (1986) for details.

Description and phenology

The mature bacuri tree may attain 20+ m in height and 50 cm in diameter at breast height and is an element of the mid-to-upper canopy in these transitional forests. The cultivated plant, grown in more open conditions, may attain 15-20 m in height and have a crown of 10-15 m in diameter. In forest individuals there is apparent apical dominance, although this is not always apparent in field-grown plants. Branches arise at an angle of 50-60° from the trunk. The short-petioled, smooth, leathery leaves mature to a dark green, attaining 8-14 cm in length by 4-8 cm in width.

The bisexual, solitary flowers are born terminally on young branches just after leaf fall. They have 5 sepals and 5 pale rose-colored petals; the numerous stamens are fused into 5 bundles; the superior ovary has 5 locules. The fruit are ovoid to subglobose, 7-15 cm long and 5-15 cm in diameter, weighing 2001000 g. The rind is thick (1-3 cm), pale yellow to brownish-yellow in color, tough and somewhat elastic, and exudes a yellow latex when bruised. The pulp is creamy white, somewhat mucilaginous, fibrous and juicy and envelopes the 1-5, generally 3 seeds. When a seed does not develop, the pulp forms a parthenocarpic segment that is greatly appreciated by consumers. The large seeds are oblong-ovoid, somewhat angular, 4-6 cm long and 2-3 cm in diameter.

The bacuri starts flowering at the beginning of the dry' season (June to September in Belém). Harvest season extends from December to May in Belém, with greatest intensity in February' and March.

Distribution, abundance and ecology

The bacuri's natural distribution is along the forest-savanna transition zone south of the Amazon forest, from the Atlantic to Paraguay (Cavalcante 1988), occurring in the Brazilian states of Pará, parts of Maranhão, Piauí, Goiás and Mato Grosso (Cavalcante 1988, FAO 1986); it is reputed to occur throughout the Amazon basin (Leon 1987, Loureiro et al. 1979), although Huber (1904) doubts that it occurs in western Amazonas state and western Amazônia in general. It also occurs in the Guianas (FAO 1986, Loureiro et al. 1979). The bacuri is probably indigenous to eastern and southeastern Amazônia (FAO 1986).

The bacuri occurs at low frequency (0.5-1.5 trees/ha) throughout the transition zone (FAO 1986) and at an even lower frequency around Manaus, where it is used for its wood rather than its fruit. There are occasional stands of 50-100 trees/ha in eastern and south-eastern Amazônia (FAO 1986). These bacuri stands are probably due to Amerindian or caboclo management.

The bacuri is common on upland soils and appears to do better on poor soils than most other regional fruit species (FAO 1986), although it responds very well on good soils. Cavalcante (1988) states, however, that one area of great abundance is on the poorly drained soils of Marajó Island and other parts of the Amazon River estuary. The species requires full sun for good growth and yield (Calzavara 1970). Throughout its distribution the dry season is moderate to severe (2-8 months) with 1,300-3,100 mm during the rainy, season (Diniz et al. 1984, FAO 1986).

Uses and economic potential

Principal use
Secondary uses

The bacuri is one of the most popular fruits on the Belém market. During the last decade several small industries in Belém have started to produce canned parthenocarpic sections, fruit puree, jams and ice creams. Some of these are now being shipped to southern Brazil but there doesn't appear to be an export market yet (Clement & Venturieri 1990).

Principal use

The bacuri pulp has only been studied as materia prima for nectar, although it is also used in ice creams, jellies, puree and canned parthenocarpic sections (Clement & Venturieri 1990). Corrêa (1926) states that fresh pulp is difficult to digest, but Cavalcante (1988) states that it is avidly consumed fresh during the season, especially the parthenocarpic sections.

Barbosa et al. (1979) present one fruit component analysis, based on small fruit (213 g average) from the Belém market. They found only 12% pulp, 18% seed and the rest exocarp. Cruz et al. (1984) found similar proportions in fruit from Maranhao, although Calzavara (1970) reports 10%, 26%, 64% respectively. Barbosa et alii's physical-chemical analysis of the pulp is presented in Table 1. Paula (1945) found 5% pectin, however, and suggested that: this would be very interesting in the food industry.

Table 1. Physical-chemical analysis of bacuri pulp (Barbosa et al. 1979).

Barbosa et al. (1979) prepared a nectar of uncertain composition and pasteurized it at 90°C for 30 seconds, sealed it in 250 ml cans with internal varnish, let it settle for 10 minutes, cooled it under running water and stored it at room temperature. They analyzed brix, pH, acidity, amino acids, vitamin C, pulp (Table 1), odor and flavor after 1 day, 1 week, 1, 2, 3 and 13 months. Brix (from 13.6 to 12.64) and pH (3.25 to 3.2) dropped slightly and amino acids (4.86 to 2.48) dropped significantly during the 13 months. All these modifications were expected by the authors. Odor and flavor remained good throughout the period. Nazaré & Melo (1981) extracted bacuri aroma and used it to flavor yogurt with good results.

Secondary uses

The seed, with its high oil levels and high percentages of palmitic and oleic fatty acids (Table 2), may have some use in industry, especially as a plantation of bacuri can theoretically produce about 3.5 T/ha/yr of seed or 1.6 t of oil per year, which makes it a very interesting alternative for oil production. Corrêa (1926), however, relates that the seed is edible and has a good nutty flavor. He also states that bacuri seed oil has medicinal uses, although he doesn't explain further.

Bentes et al. (1986/87) studied the fatty acid composition of the bacuri seed oil from Belém, which is about 46% of seed fresh weight (about 28% is water), although Cruz et al. (1984) found 71% oil in their sample from Maranhão. Their results are presented in Table 2. Bentes et al. (1986/87) also found about 10% of tripalmitin, a methyl ester of palmitic acid. The two analyses present considerable differences in palmitic (C16: 0) and oleic (C18: 1) acid proportions, as well as in the other acids. This suggests that fatty acid composition could be easily selected for and maintained through vegetative propagation if the species were to be used as an oil crop.

Table 2. Fatty acid composition (%) and physical-chemical constants of bacuri seed oil (Bentes et al. 1986/87, Cruz et al. 1984).

The exocarp (rind) is the major by-product in terms of quantity. At the moment it recommended as compost and returned to the plantation to improve soil quality and reduce mineral fertilizer inputs (Cavalcante 1970). There may be an industrial use for the yellow latex, similar to that found in all Gutiferae, and is identified as a resinotonol (Paula 1945). Berg (1982) states that this latex (both from the fruit and the trunk) has medicinal properties, specifically when applied topically for skin ailments, such as eczema and herpes.

Loureiro et al. (1979) describe the wood as heavy (0.8-0.85 g/cm³), with a rosy beige color in the heart wood and a light beige outer wood, a straight grain, with a rough texture, no smell or distinctive taste. It is easy to work and takes a good finish. It is employed in general carpentry and furniture making, as well as in civil and marine construction.

Collection methods and yields

The fruit fall when ripe, so-that harvesting consists of collection from the ground. Because of the thick, durable rind the fruit do not bruise easily and can be transported over great distances and remain in good condition. The pulp remains consumable for 5-10 days within the fruit, counting from fruit fall (FAO 1986).

A vigorous, mature seedling tree (15-20 years old) will produce about 500 fruit per season (Calzavara 1970), although some have been observed to produce 800-1,000 (FAO 1986). At 115 plants/ha, Calzavara's recommended monoculture spacing, the yield of fresh fruit may exceed 20 MT. This is only 2.4 MT/ha of pulp, however, so it will be important to develop utilization for the seed (3.6 MT/ha) and the rind (14 MT/ha).

Propagation and cultivation methods

Propagation by seed, grafting or root cuttings is reputed to be easy, spacing and the rudiments of fertilization are known (Calzavara 1970): cleaned seed from elite trees are sown in a nutrient-rich, light textured seed bed, where germination will start within two to three months (A. Kato, CPATU, reports that the radicle develops first and that shoot development may only occur several months later); when the plantlets are 20 cm tall they are transplanted to a polibag nursery, where they will remain until 60 cm tall, when they will be hardened-off.

Field planting should be done at the beginning of the rainy season, at 10 m triangular spacing (115 trees/ha) in 50 cm planting pits, previously enriched with manure, 500 g dolomitic calcium, and 100 g each of superphosphate and potash. Bacuri can be intercropped with annuals or short lived perennials during the first years. Seedling trees may take 6-10 years to start yielding, while grafted plants may take 3-5 years (FAO 1986). Top cleft grafting has given good results on bacuri root-stock (A. Kato, CPATU, pers. com.), while root cuttings have given variable results, apparently depending upon time of year.

It is probable that phytosanitary problems will develop as cultivation becomes more intensive, but bacuri currently has so few pests, probably because of the latex, that it is impossible to guess which might became limiting.

Given bacuri's adaptation to nutrient poor soils in southern Amazônia this species could become an important multipurpose (fruit, nut, oil, timber) agroforestry or monoculture species for recuperation of degraded sites. The small research efforts that exist (at CPATU, in Belém, and EMAPA, in Maranhão) are poorly funded but because they have quality staff could provide significant information rapidly with adequate support.

Research contacts

Prof. B.B.G. Calzavara, Centro de Pesquisas Agropecuárias do Trópico Úmido - CPATU/EMBRAPA, Cx. Postal 48, 66040 Belém, Pará, Brazil.

Commercial contacts

Gelar S.A. Indústrial Alimentícias, Belém, Pará, Brazil.

Industria São Vicente, Belém, Pará, Brazil.