Index | Search | Home | Table of Contents
Serudin, Hj. D.S. and Hj. Tinggal. 1993. Garcinia hombrioniana: A potential fruit and an industrial crop. p. 472-474. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.

Garcinia hombrioniana: A Potential Fruit and an Industrial Crop

Hj. Serudin D.S. Hj. Tinggal*

  1. BOTANY
    1. Origin
    2. Morphology
  2. HORTICULTURE
    1. Culture
  3. UTILIZATION
  4. FUTURE PROSPECTS
  5. Fig. 1
  6. Fig. 2
  7. Fig. 3
  8. Fig. 4
Southeast Asia is regarded as a major center of origin and evolution of many cultivated crops particularly tropical fruits. A great variety of fruits, some wild, others cultivated are located in Brunei. Species of Artocarpus, Durio, Garcinia, Mangifera, Musa, and Nephelium, to mention only a few, occur as scattered species amidst forest trees or growing alongside homes, in backyards or mixed orchards. These indigenous species together with introduced cultivars represent invaluable genetic resources waiting to be collected, identified, and tested for commercial development.

One of these potential new fruit crops is Garcinia hombrioniana Pierre, locally called Assam Aur Aur, a close relative of the mangosteen, G. mangostana L. The attractive fruit contains white segmented luscious pulp, sweet with a pleasing fragrance similar to apricot (Fig. 1). The pulp has many uses. The dried crimson rind of the fruit for example, is commercially important and used extensively as sour relish in curries and culinary dishes requiring an acidulous base. Demand for this condiment is seemingly unsatisfiable and at every fruit season, housewives gather the fruits, remove the pulp, and sun-dry the rind (Fig. 2). The market price is attractive and keeping quality for properly dried pulp is good.

BOTANY

Origin

Assam Aur Aur is native to the Brunei Bay region of the states of Sabah and Sarawak of Malaysia and Brunei. The tree probably originated in the rainforests and was cultivated in the coastal and riverine regions to serve the culinary uses of the early settlers. Currently, the distribution is still restricted to the riverine and coastal alluvial regions. Some trees are found in the interior settlements, probably introduced, as coastal and riverine dwellers moved to settle inland. The fruit has never achieved the importance of mangosteen and early explorers and naturalists have largely neglected the small fruit for the larger, sweeter mangosteen.

Morphology

Assam Aur Aur is a handsome evergreen closely resembling the mangosteen in shape and canopy structure, except that Assam Aur Aur has smaller, more elliptical leaves. Mature trees can reach 10 m in height with numerous radially arranged spreading branches. Much of the leaves are held by tertiary branches. Inflorescence are borne on these branchlets in clusters of not more than five small flowers. Very little is known about the morphology of the flowers and owing to the smallness and almost fused structures, the flowers have received very little attention. It is likely that the flowers are hermaphroditic and the few seeds produced apomictic. Seedlings derived from seeds are always identical to the mother plant; there is no known genetic variation. Subtle differences in size (3 to 5 cm in diameter) and shape of fruits could be attributed to environmental influence. The population is generally homogeneous making selection for superior types difficult. However, this homogeneous attribute can be advantageous as fruit and fruit products derived from the fruits are fairly uniform.

HORTICULTURE

Culture

Assam Aur Aur is a tropical species requiring humid conditions of uniform annual rainfall exceeding 2,000 mm and mean temperature of 27°C. The tree shows a wide range of soil adaptability and will grow on damp alluvial soil as well as free draining upland soils. However, the preference is for well-drained fertile alluvial soil where water is not limiting.

Seeds, with the pulp removed, germinate within one week and can be shown direct into plastic bags. Early growth requires protection from full sunlight; 50% shading is recommended and progressively removed to harden the seedlings for field planing when 6 to 8 months old.

There is no commercial planting of Assam Aur Aur to provide cultural recommendations. However, based on observations and experiences, trees grow best at 5 m spacing. Nurse shade between 50 to 60% is essential at planting. Growth is rapid. Prunning of lower branches, weeding, and fertilization will bring the trees to bear after four years. Recommended fertilizers consist of NPK (12-5-14) to enhance fruiting. Mulching with dry litter will help to retain soil moisture and prevent erosion which appears to be essential for healthy growth of the plant.

As long as the trees are healthy, problems of diseases appear minimal. However, ripe fruits are susceptible to infection by fruit flies (Dacus spp) causing damage to the pulp. The rind is unaffected and can still be processed into condiments. Fruit fly damage is more prevalent when few fruits are in season. Spraying with insecticides may reduce the damage, but, generally control of fruit fly is difficult in the tropics.

UTILIZATION

Bruneians, for centuries, have found many uses for the fruits. The young fruits that drop to the ground are collected and sliced into thin pieces or chunks and sun-dried. The final product is a fig brown condiment ready to give the needed tang to Brunei dishes. Currently, there is a limited amount in the market. The mature fruit has multiple uses with a fragrance reminiscent of apricot. Early Bruneians fermented the pulp into organic vinegar. The flavor is distinct, fruity, and strong. In recent years, efforts of the Department of Agriculture have produced suitable cordials and jams from the pulp (Fig. 3). The quality of the cordial is still questionable but the jams have penetrated a limited market. Research is still in progress.

The greatest commercial value of the fruit is the crimson rind. Dried in the sun, the shiny rind turns dull mauve in the process. Packed into small plastic bags, the rind is ready for sale as an essential ingredient for many Brunei dishes. The best condiment exudes some oil when pressed between fingers and quality rind, properly dried, will eventually turn black without being moldy (Fig. 4). Dark colored rind does not affect the culinary quality.

FUTURE PROSPECTS

Assam Aur Aur has tremendous opportunity as a specially fruit. Strong promotional support will strengthen marketing. The research programs of the Department of Agriculture can explore postharvest and handling technology to establish quality and standards. However, it is the inherent quality of fruit that will attract connoisseurs. The strategy is to introduce this fruit into specially markets.

Another area of interest is the acidulous quality of the rind. It is already in great demand. Opportunity exists for more systematic and scientific approach to rind processing, packaging, and marketing. Greater efforts will be required to evaluate value-added products such as jams, juices, and food colors.

*There is no known published data on Assam Aur Aur. The information presented has been collected by the author during various field trips to the countryside and discussion with farmers and their families. Officers of the Department of Agriculture provided valuable information on its culture and food processing.

Fig. 1. Close up of the savory Assam Aur Aur fruit.

Fig. 2. Sun-drying of Assam Aur Aur rind with the pulp removed.

Fig. 3. Assam Aur Aur conserve produced by the Department of Agriculture, Brunei.

Fig. 4. Dried rind of Assam Aur Aur used as sour relish (left: freshly dried; right: after six months storage).

Last update September 15, 1997 aw