From the book
Fruits of Warm Climates
by Julia F. Morton
Bael Fruit
Aegle marmelos Correa
syn. Feronia pellucida Roth, Crataeva marmelos L.
RUTACEAE
Though
more prized for its medicinal virtues than its edible quality, this
interesting member of the family Rutaceae is, nevertheless, of
sufficient importance as an edible fruit to be included here. The bael
fruit, Aegle marmelos Correa (syns. Feronia pellucida Roth., Crataeva marmelos
L.), is also called Bengal quince, Indian quince, golden apple, holy
fruit, stone apple, bel, bela, sirphal, maredoo and other dialectal
names in India; matum and mapin in Thailand; phneou or pnoi in
Cambodia; bau nau in Vietnam; bilak, or maja pahit in Malaya; modjo in
Java; oranger du Malabar in French; marmelos in Portuguese. Sometimes
it is called elephant apple, which causes confusion with a related
fruit of that name, Feronia limonia Swingle (q.v.).
Fig. 47: A hard-shelled bael fruit (Aegle marmelos), of the
type valued more for medicinal purposes than for eating.
Description
The bael fruit
tree is slow-growing, of medium size, up to 40 or 50 ft (12-15 m) tall
with short trunk, thick, soft, flaking bark, and spreading, sometimes
spiny branches, the lower ones drooping. Young suckers bear many stiff,
straight spines. A clear, gummy sap, resembling gum arabic, exudes from
wounded branches and hangs down in long strands, becoming gradually
solid. It is sweet at first taste and then irritating to the throat.
The deciduous, alternate leaves, borne singly or in 2's or 3's, are
composed of 3 to 5 oval, pointed, shallowly toothed leaflets, 1 1/2 to
4 in (4-10 cm) long, 3/4 to 2 in (2-5 cm) wide, the terminal one with a
long petiole. New foliage is glossy and pinkish-maroon. Mature leaves
emit a disagreeable odor when bruised. Fragrant flowers, in clusters of
4 to 7 along the young branchlets, have 4 recurved, fleshy petals,
green outside, yellowish inside, and 50 or more greenish-yellow
stamens. The fruit, round, pyriform, oval, or oblong, 2 to 8 in (5-20
cm) in diameter, may have a thin, hard, woody shell or a more or less
soft rind, gray-green until the fruit is fully ripe, when it turns
yellowish. It is dotted with aromatic, minute oil glands. Inside, there
is a hard central core and 8 to 20 faintly defined triangular segments,
with thin, dark-orange walls, filled with aromatic, pale-orange, pasty,
sweet, resinous, more or less astringent, pulp. Embedded in the pulp
are 10 to 15 seeds, flattened-oblong, about 3/8 in (1 cm) long, bearing
woolly hairs and each enclosed in a sac of adhesive, transparent
mucilage that solidifies on drying.
Origin and
Distribution
The
tree grows wild in dry forests on hills and plains of central and
southern India and Burma, Pakistan and Bangladesh, also in mixed
deciduous and dry dipterocarp forests of former French Indochina.
Mention has been found in writings dating back to 800 B.C. It is
cultivated throughout India, mainly in temple gardens, because of its
status as a sacred tree; also in Ceylon and northern Malaya, the drier
areas of Java, and to a limited extent on northern Luzon in the
Philippine Islands where it first fruited in 1914. It is grown in some
Egyptian gardens, and in Surinam and Trinidad. Seeds were sent from
Lahore to Dr. Walter T. Swingle in 1909 (P.I. No. 24450). Specimens
have been maintained in citrus collections in Florida and in
agriculture research stations but the tree has never been grown for its
fruit in this state except by Dr. David Fairchild at his home, the
"Kampong", in Coconut Grove, after he acquired a taste for it, served
with jaggery (palm sugar), in Ceylon.
Soil
The bael fruit is said to do best on rich, well-drained soil, but it
has grown well and fruited on the oolitic limestone of southern
Florida. According to L. B. Singh (1961), it "grows well in swampy,
alkaline or stony soils". . . "grows luxuriantly in the soils having pH
range from 5 to 8". In India it has the reputation of thriving where
other fruit trees cannot survive.
Climate
The
bael fruit tree is a subtropical species. In the Punjab, it grows up to
an altitude of 4,000 ft (1,200 m) where the temperature rises to 120º F
(48.89º C) in the shade in summer and descends to 20º F (-6.67º C) in
the winter, and prolonged droughts occur. It will not fruit where there
is no long, dry season, as in southern Malaya.
Varieties
One esteemed,
large cultivar with thin rind and few seeds is known as 'Kaghzi'. Dr.
L.B. Singh and co-workers at the Horticultural Research Institute,
Saharanpur, India, surveyed bael fruit trees in Uttar Padesh, screened
about 100 seedlings, selected as the most promising for commercial
planting: 'Mitzapuri', 'Darogaji', 'Ojha', 'Rampuri', 'Azamati',
'Khamaria'. Rated the best was 'Mitzapuri', with very thin rind,
breakable with slight pressure of the thumb, pulp of fine texture, free
of gum, of excellent flavor, and containing few seeds.
S.K. Roy,
in 1975, reported on the extreme variability of 24 cultivars collected
in Agra, Calcutta, Delhi and Varanasi. He decided that selections
should be made for high sugar content and low levels of mucilage,
tannin and other phenolics.
Only the small, hard-shelled type is
known in Florida and this has to be sawed open, cracked with a hammer,
or flung forcefully against a rock. Fruits of this type are standard
for medicinal uses rather than for consuming as normal food.
Propagation
The bael fruit
is commonly grown from seed in nurseries and transplanted into the
field. Seedlings show great variation in form, size, texture of rind,
quantity and quality of pulp and number of seeds. The flavor ranges
from disagreeable to pleasant. Therefore, superior types must be
multiplied vegetatively. L.B. Singh achieved 80% to 95% success in 1954
when he budded 1-month-old shoots onto 2-year-old seedling bael
rootstocks in the month of June. Experimental shield-budding onto
related species of Afraegle and onto Swinglea glutinosa Merr. has been successful. Occasionally, air-layers or root cuttings have been used for propagation.
Culture
The tree has no
exacting cultural requirements, doing well with a minimum of fertilizer
and irrigation. The spacing in orchards is 25 to 30 ft (6-9 m) between
trees. Seedlings begin to bear in 6 to 7 years, vegetatively propagated
trees in 5 years. Full production is reached in 15 years. In India
flowering occurs in April and May soon after the new leaves appear and
the fruit ripens in 10 to 11 months from bloom–March to June of the
following year.
Harvesting
Normally,
the fruit is harvested when yellowish-green and kept for 8 days while
it loses its green tint. Then the stem readily separates from the
fruit. The fruits can be harvested in January (2 to 3 months before
full maturity) and ripened artificially in 18 to 24 days by treatment
with 1,000 to 1,500 ppm ethrel (2-chloroethane phosphonic acid) and
storage at 86° F (30°C). Care is needed in harvesting and handling to
avoid causing cracks in the rind.
A tree may yield as many as 800 fruits in a season but an average crop is 150 to 200, or, in the better cultivars, up to 400.
Keeping
Quality
Normally-harvested
bael fruits can be held for 2 weeks at 86° F (30°C), 4 months at
48.2° F (9°C). Thereafter, mold is likely to develop at the stem-end
and any crack in the rind.
Pests and
Diseases
The bael fruit seems to be relatively free from pests and diseases except for the fungi causing deterioration in storage.
Food Uses
Bael fruits may be
cut in half, or the soft types broken open, and the pulp, dressed with
palm sugar, eaten for breakfast, as is a common practice in Indonesia.
The pulp is often processed as nectar or "squash" (diluted nectar). A
popular drink (called "sherbet" in India) is made by beating the seeded
pulp together with milk and sugar. A beverage is also made by combining
bael fruit pulp with that of tamarind. These drinks are consumed
perhaps less as food or refreshment than for their medicinal effects.
Mature
but still unripe fruits are made into jam, with the addition of citric
acid. The pulp is also converted into marmalade or sirup, likewise for
both food and therapeutic use, the marmalade being eaten at breakfast
by those convalescing from diarrhea and dysentery. A firm jelly is made
from the pulp alone, or, better still, combined with guava to modify
the astringent flavor. The pulp is also pickled.
Bael pulp is
steeped in water, strained, preserved with 350 ppm S02, blended with
30% sugar, then dehydrated for 15 hrs at 120° F (48.89° C) and
pulverized. The powder is enriched with 66 mg per 100 g ascorbic acid
and can be stored for 3 months for use in making cold drinks
("squashes"). A confection, bael fruit toffee, is prepared by combining
the pulp with sugar, glucose, skim milk powder and hydrogenated fat.
Indian food technologists view the prospects for expanded bael fruit
processing as highly promising.
The young leaves and shoots are
eaten as a vegetable in Thailand and used to season food in Indonesia.
They are said to reduce the appetite. An infusion of the flowers is a
cooling drink.
| Food
Value Per
100 g of Edible Portion* |
| Water
|
54.96-61.5 g |
| Protein |
1.8-2.62 g |
| Fat
|
0.2-0.39 g |
| Carbohydrates |
28.11-31.8 g |
| Ash |
1.04-1.7 g |
| Carotene |
55 mg |
| Thiamine |
0.13 mg |
| Riboflavin |
1.19 mg |
| Niacin |
1.1 mg |
| Ascorbic Acid |
8-60 mg |
| Tartaric Acid |
2.11 mg |
| *Fresh bael fruit, as analyzed in India and in the Philippines. |
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The pulp also contains a balsam-like substance, and 2
furocoumarins-psoralen and marmelosin (C13H12O3), highest in the pulp
of the large, cultivated forms.
There is as much as 9% tannin in
the pulp of wild fruits, less in the cultivated types. The rind
contains up to 20%. Tannin is also present in the leaves, as is
skimmianine.
The essential oil of the leaves contains
d-limonene, 56% a-d-phellandrene, cineol, citronellal, citral; 17%
p-cyrnene, 5% cumin aldehyde. The leaves contain the alkaloids
O-(3,3-dimethylallyl)-halfordinol, N-2-ethoxy-2-(4-methoxyphenyl)
ethylcinnamide, N-2-methoxy-2-[4-(3',3'-dimethyalloxy)
phenyll]ethylcinnamide, and
N-2-methoxy-2-(4-methoxyphenyl)-ethylcinnamamide.
Toxicity
The
leaves are said to cause abortion and sterility in women. The bark is
used as a fish poison in the Celebes. Tannin, ingested frequently and
in quantity over a long period of time, is antinutrient and
carcinogenic.
Other Uses
Fruit: The fruit pulp has
detergent action and has been used for washing clothes. Quisumbing says
that bael fruit is employed to eliminate scum in vinegar-making. The
gum enveloping the seeds is most abundant in wild fruits and especially
when they are unripe. It is commonly used as a household glue and is
employed as an adhesive by jewelers. Sometimes it is resorted to as a
soap-substitute. It is mixed with lime plaster for waterproofing wells
and is added to cement when building walls. Artists add it to their
watercolors, and it may be applied as a protective coating on paintings.
The
limonene-rich oil has been distilled from the rind for scenting hair
oil. The shell of hard fruits has been fashioned into pill- and snuff
boxes, sometimes decorated with gold and silver. The rind of the unripe
fruit is employed in tanning and also yields a yellow dye for calico
and silk fabrics.
Leaves: In the Hindu culture, the leaves are indispensable offerings to the 'Lord Shiva'. The leaves and twigs are lopped for fodder.
Flowers: A cologne is obtained by distillation from the flowers.
Wood
The wood is strongly aromatic when freshly cut. It is gray-white, hard,
but not durable; has been used for carts and construction, though it is
inclined to warp and crack during curing. It is best utilized for
carving, small-scale turnery, tool and knife handles, pestles and
combs, taking a fine polish.
Medicinal
Uses:
The fresh ripe pulp of the higher quality cultivars, and the "sherbet"
made from it, are taken for their mild laxative, tonic and digestive
effects. A decoction of the unripe fruit, with fennel and ginger, is
prescribed in cases of hemorrhoids. It has been surmised that the
psoralen in the pulp increases tolerance of sunlight and aids in the
maintaining of normal skin color. It is employed in the treatment of
leucoderma. Marmelosin derived from the pulp is given as a laxative and
diuretic. In large doses, it lowers the rate of respiration, depresses
heart action and causes sleepiness.
For medicinal use, the young
fruits, while still tender, are commonly sliced horizontally and
sun-dried and sold in local markets. They are much exported to Malaya
and Europe. Because of the astringency, especially of the wild fruits,
the unripe bael is most prized as a means of halting diarrhea and
dysentery, which are prevalent in India in the summer months. Bael
fruit was resorted to by the Portuguese in the East Indies in the
1500's and by the British colonials in later times.
A bitter,
light-yellow oil extracted from the seeds is given in 1.5 g doses as a
purgative. It contains 15.6% palmitic acid, 8.3% stearic acid, 28.7%
linoleic and 7.6% linolenic acid. The seed residue contains 70% protein.
The
bitter, pungent leaf juice, mixed with honey, is given to allay catarrh
and fever. With black pepper added, it is taken to relieve jaundice and
constipation accompanied by edema. The leaf decoction is said to
alleviate asthma. A hot poultice of the leaves is considered an
effective treatment for ophthahnia and various inflammations, also
febrile delirium and acute bronchitis.
A decoction of the
flowers is used as eye lotion and given as an antiemetic. The bark
contains tannin and the cournarin, aegelinol; also the furocourmarin,
marmesin; umbelliferone, a hydroxy coumarin; and the alkaloids,
fagarine and skimmianine. The bark decoction is administered in cases
of malaria. Decoctions of the root are taken to relieve palpitations of
the heart, indigestion, and bowel inflammations; also to overcome
vomiting.
The fruit, roots and leaves have antibiotic activity.
The root, leaves and bark are used in treating snakebite. Chemical
studies have revealed the following properties in the roots: psoralen,
xanthotoxin, O-methylscopoletin, scopoletin, tembamide, and skimmin;
also decursinol, haplopine and aegelinol, in the root bark.
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