From Plant
Resources of South-East Asia No 2: Edible fruits and nuts, PROSEA
Foundation
by A. T. Sunarto
Taxon
Aegle marmelos (L.)
Correa
Protologue
Trans. Linn. Soc. London 5: 223 (1800).
Family
RUTACEAE
Chromosome
Numbers
2n = 18 (36)
Vernacular
Names
Bael or bel fruit (En). Bel Indien (Fr). Indonesia: maja, maja batu.
Malaysia: bilak, bila, bel. Philippines: bael. Burma: opesheet, okshit.
Cambodia: bnau. Laos: toum. Thailand: matum, tum (Pattani), ma pin
(north). Vietnam: trái mam.
Origin and
Geographic Distribution
Bael grows wild in dry forests in the Indian Peninsula, Sri Lanka,
Pakistan and Bangladesh. It is an old cultivated tree in that region,
particularly found in temple gardens in India. It has spread to
Indo-China, South-East Asia (in particular Thailand, northern Malaysia,
eastern Java and northern Luzon) and other parts of the tropics.
Uses
Ripe
fruit is eaten fresh and is also prepared as a sherbet, syrup,
marmalade and fruit nectar. The mucilage around unripe seeds is used as
an adhesive and household glue. The extract of leaf and young fruit was
used in Java to adulterate opium. In Java the nearly ripe fruit is
sliced, dried and applied against chronic dysentery, diarrhoea and
constipation. Ripe fruit extract is also used against rectum
inflammation. The rind of unripe fruit can be used as a yellow dye and
as a tanning agent.
In Indo-China bark and leaves are used against intermittent fever, but
in Sulawesi the bark is used to poison fish. Young leaves are used for
seasoning in Java, although one source says they may cause abortion and
sterility in women; together with betel pepper and lime they are rubbed
on itching skin and used as poultice for wounds. In Madura the leaf
juice is used against foot-and-mouth disease in cattle. The root is
used against heart palpitation, indigestion and bowel inflammation. The
wood is suitable for making small articles such as 'keris' (ceremonial
dagger) handles.
Properties
The pulp is soft, yellow or orange, very fragrant and pleasantly
flavoured. The edible portion (pulp) amounts to 56—77% of the fruit and
contains per 100 g: water 61.5 g, protein 1.8 g, fat 0.39 g,
carbohydrates 31.8 g, ash 1.7 g, carotene 55 mg, thiamine 0.13 mg,
riboflavin 1.19 mg, niacin 1.1 mg, and vitamin C 8 mg. The fruit is
rich in tannin (up to 20% in the rind). Marmelosine (C13H12O3),
volatile oil, limonene, alkaloids, coumarines and steroids are also
present in different parts of the tree.
Botany
Small deciduous tree, 10—15 m tall, trunk 25—50 cm in diameter. Older
branches spiny; spines single or paired, 1—2 cm long. Leaves alternate,
trifoliolate; petiole 2—4 cm long, lateral petiolules up to 3 mm,
terminal up to 15 mm long; lateral leaflets ovate to elliptic, up to 7
cm x 4.2 cm, terminal obovate, up to 7.5 cm x 4.8 cm, densely minutely
glandular-punctate. Inflorescences axillary racemes, 4—5 cm long,
clustered; sepals broadly deltoid, 1.5 mm long; petals oblong-obovate,
14 mm x 8 mm, greenish to white; stamens 35—45, white, filaments 4—7 mm
long; ovary 8 mm x 4 mm, style very short. Fruit a subglobose berry,
5—12.5 cm diameter, often with a hard woody shell, of 8—16(—20)
segments, with 6—10 seeds in a clear, sticky, edible pulp. Seeds
woolly-pubescent, enclosed in a sac of adhesive mucilage which
solidifies on drying; testa white.
Ecology
Bael is a hardy, deciduous tree of the subtropics. It grows under harsh
conditions, including extremes of temperature, e.g. from 49°C in summer
to —7°C in winter in Punjab, up to 1200 m elevation. In South-East Asia
it only flowers and fruits well where there is a prominent dry season
and it is not usually found above 500 m. The tree grows on swampy land
as well as dry soils and tolerates alkalinity.
Agronomy
Bael is usually propagated by seed; the seedlings are planted out after
one year, 6—9 m apart. It can be propagated vegetatively by root
suckers, or through budding, also on seedlings of other Aegle species and Swinglea glutinosa
(Blanco) Merr. Vegetatively propagated plants bear fruit after 5 years
and full bearing can be attained in about 15 years. The fruit ripens in
the dry season, when most leaves have been shed in anticipation of
bloom for the next crop. No serious pests and diseases have been
reported.
Bael fruit is picked individually and should not be allowed to drop.
Yield per tree is 200—400 fruit. The fruit is packed in baskets, gunny
bags or wooden boxes. Cracked fruit is susceptible to fungal infection.
Genetic
Resources and Breeding
Seedlings show much variation in fruit characteristics. Cultivated
trees generally are spineless and have much larger fruit with better
quality pulp. In India cultivars are named after the locality where
they became popular. Even for these cultivars, fruit quality differs
greatly; 'Kaghzi' and 'Mitzapuri' have been selected for their large
fruit, thin rind, few seeds and fine pulp texture and flavour.
Evidently the potential of the fruit can only be appreciated after
tasting such superior types.
Prospects
Since the pulp from ripe fruit turns brown and develops off-flavours
during extraction and processing, ripe fruit so far could only be
consumed fresh, and green fruit had to be used to make preserves. New
processing techniques preserve the quality of pulp from ripe fruits.
Coupled with the quality of superior cultivars this may enhance the
prospects for growing bael as a fruit for processing. Its soluble solid
content is 28—36%, nearly twice as high as in most other fruits, making
a wide range of products feasible. To assess the prospects for bael in
South-East Asia it should first be investigated whether yield and fruit
quality are as good as in India.
Literature
Atmodiwirjo, A.T.S., 1983. Maja (Aegle
marmelos Corr.) kemungkinan pengembangan dan pengolahan
buahnya. [Bael fruit (Aegle
marmelos Corr.), the scope for development and fruit
processing]. Buletin Kebun Raya 6(2): 35—38.
Roy, S.K., 1985. Bael. In: Bose, T.K. (Editor): Fruits of India,
tropical and subtropical. Chapter 19. Naya Prokash, Calcutta. pp.
498—504.
Roy, S.K. Singh, R.N., 1979. Bael fruit (Aegle marmelos) - A
potential fruit for processing. Economic Botany 33(2): 203—212.
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