Scientific Name and Introduction Coconut (Cocos nucifera L.)
It is
marketed at two stages of development. At an immature stage, the fruit (water
coconut) contains mainly water and a little jellylike meat instead of the hard,
white flesh (meat/endosperm) found in mature coconuts immature green nuts are
trimmed and shaped, removing most of the husk. The final product has a flat
bottom, round body with a pyramid top, and the eyes showing.
To prevent
browning of the remaining husk, nuts are dipped in 1 to 3% sodium
meta-bisulfite for 2 to 5 min and then wrapped in plastic film (Tongdee et al.
1991). Sometimes fungicide is included in the sulfite solution. Alternatively,
the husk is removed before dipping in sulfite solution. Fruit are available
year round from most tropical countries (Seelig 1970). Quality Characteristics
and Criteria Major quality characteristics are maturity, size, and freedom from
blemishes, cracking, fiber of husked coconuts, and wet or moldy eyes. Check for
a sloshing sound for presence of coconut water in the nut.
Coconut milk is obtained by removing and
grating the hard, white flesh and squeezing out the milky juice. Immature,
dehusked coconuts are about 10 cm (4 in) in diameter, weigh about 500 g (1.1
lb), have 100 g (3.5 oz) endosperm, 120 g (4.2 oz) shell, and 250 g (8.8 oz)
water. Horticultural Maturity Indices Young coconuts are harvested 6 to 9 mo
after flowering as they approach full size and the skin is still green and the
short stem on the top of individual coconuts that originally held the male
flowers becomes half green and brown. In immature nuts, the skin surface around
the calyx (cap) on the top of the coconut is creamy white or a whitish yellow.
When the area surrounding the cap is green, the coconut is considered mature
and is 10 to 12 mo old.
At maturity the
skin begins to change from green to yellow, then brown, and the “rat-tail” is
entirely brown. Grades, Sizes, and Packaging There are no specific grades;
informal grades are generally based on size and weight.
Mature
dehusked coconuts are sold in 34- to 36-kg
(75- to 80-lb) woven plastic or burlap sacks containing 50 to 60 coconuts,
plastic mesh bags of 12 coconuts, and cartons with 20 to 25 filmwrapped
coconuts weighing 17 to 18 kg (37 to 40 lbs). Immature coconuts (water
coconuts) are shaped, dipped in bisulphate, and film-wrapped.
They are sold
in single-piece cartons containing 10 to 16 nuts. For young coconuts, the
entire husk is removed, and the nuts are then dipped in sodium bisulfite before
packing. Precooling Conditions Room cooling is generally used for mature husked
nuts. Forced-air cooling and hydrocooling are acceptable.
A rapid
temperature change of 8 ºC (14 °F) or greater can cause cracking. Optimum
Storage Conditions Mature coconuts with husk can be kept at ambient conditions
for 3 to 5 mo before the liquid endosperm evaporates or before the shell cracks
due to desiccation or sprouting.
Storage at 0
to 1.5 ºC (32 to 35 ºF) and 75 to 85% RH is possible for up to 60 days for
mature, dehusked coconuts and 13 to 16
ºC (55 to 60 ºF) and 80 to 85% RH for 2 weeks or less. Low RH and high
temperature should be avoided. Young coconuts are normally held at 3 to 6 ºC
(37 to 43 ºF) with 90 to 95% RH, while wrapped and shaped fruit can be held for
3 to 4 weeks.
Shaped young
coconuts treated with 0.5 to 1.0% sodium meta-bisulfite can be held at ambient
temperature for 2 days before browning occurs, while those treated with 2%
sodium meta-bisulfite can be held at ambient temperature for 2 to 7 days
(Tongdee et al. 1992). Young coconuts that have not been dehusked can be stored
for a longer period than dehusked or shaped young coconuts. In dehusked or
shaped coconuts, soluble solids content (SSC) declines and total acidity (TA)
increases more rapidly than in nondehusked coconuts. Thus, the taste of
dehusked or shaped coconuts sours more rapidly than nondehusked coconuts during
storage The husk acts as an insulator and may increase the storage life of
young coconuts.
