Coconut - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 158

Postharvest storage of mature coconuts
Mature coconuts harvested may be used either for fresh
nuts consumption or for further processing. If the harvested
nuts are to be used for fresh consumption, they may have
to be dehusked partially in order to facilitate handling and
transportation. The green epicarp is usually removed while
retaining the surrounding coir component attached directly
onto the nutshell. The coir component not only protects the
nut from any possible cracks during handling or transporta-
tion but may also serve as a protective cover against any
microbial contamination. As there is a market potential for
fresh nuts in the Middle East and the Europe, the partially
dehusked nuts are packed in gunny bags before shipment.
Prior to the shipment, they may be subjected to fumigation
to ensure that the gunny bags are free from insects. With
this method of processing, fresh nuts can last up to 3 weeks
before reaching the destination.
For commercial processing of copra and desiccated co-
conut (DC), freshly harvested green nuts have to be kept in
storage for a period of about 5-6 weeks in the open yard.
Traditionally known as the “seasoning” period, this step
would generally facilitate the preprocessing operations. In
the DC industry, for instance, seasoning of coconuts usually
helps to ease difficulties in the deshelling operation. Owing
to the effect of the environmental heating, the kernel in-
side could become loosely attached to the nut shell during
seasoning.

Table 9.4. Physicochemical characteristics of
fresh 'King' coconut water at different stages
of maturity.

Maturity Stage

Quality Parameters 7-8 Months 8-9 Months

Soluble solids ( ◦ Brix) 5.08 6.10

Glucose (g/100 ml) 2.4 2.9

Fructose (g/100 ml) 2.1 2.5

Sucrose (g/100 ml) — 0.4

Total sugar (g/100 ml) 5.0 6.3

pH 4.83 5.29

Potassium (mg/100 ml) 198.7 215.8

Calcium (mg/100 ml) 14.5 11.5

Magnesium (mg/100 ml) 4.6 5.1

Chloride (mg/100 ml) 144.6 157.4

Source: Ranasinghe et al. (2003).

extend the shelf life of 'King' coconut under cold storage
conditions (Ranasinghe et al., 1999, 2003).
Of the various methods proposed for the preservation of
tender nuts, guidelines developed by the Coconut Research
Institute of Sri Lanka have shown tremendous commer-
cial success. Initially, bunches with optimum maturity are
selected first. On the basis of the sugar profiles and pH
variations at different stages of maturity, the right time of
harvest of tender nuts is about 7-8 months (Table 9.4). Af-
ter the harvest of tender nuts, care must be exercised during
handling and transportation to avoid any damages which
might affect the outer appearance of nuts. When separating
an individual nut from the bunch, a sharp knife disinfected
with alcohol should be used. In the next step, fruit stalks
are cut, followed by manual cleaning to remove any dust
or debris. After cleansing, an appropriate fungicide would
be applied to the whole nut using cotton wool. To protect
nut surfaces from drying out, the whole nut is wrapped in
polypropylene cling wrap. The nuts are then covered with
a net-type cushioning (McFoam Net) to avoid any physical
damage during handling, transportation, and storage. For
packing, seven-ply corrugated boxes of 20 ×

Postharvest storage of tender 'King' coconuts
Postharvest preservation of tender nuts has become a new
business venture in recent years due to the ever increasing
demand for natural beverages all over the world. Partic-
ularly, there is a good market potential for tender nut of
'King' coconut variety found in Sri Lanka. Although ten-
der coconut could be air-freighted successfully within a day
or two, this might not be economically viable when consid-
ering large volume of export. On the contrary, sea freight
would be the most economical means of transportation for
the export of tender nut. As the shipping time takes around
2-3 weeks to reach the destination, postharvest preservation
of tender nuts is necessary. But the storage of tender 'King'
coconut for more than 1 week under ambient temperature
might not be possible due to shrinkage of nuts, discoloration
of the outer skin (epicarp), the detachment of perianth, or
fungal attack on the soft region under the perianth as well as
the deterioration of the quality of nut water. As storability
improvements to tender 'King' coconut would be promis-
ing, much effort was dedicated to developing a protocol to

8
size, with two round vent holes of 1 diameter on each long
side, are recommended. Depending on the nut size, each
box can accommodate six to eight coconuts. The packed
nuts are transferred to cold storage, at 13 ◦ -15 ◦ C and 70%
RH; under these conditions, tender nuts can be kept in fresh
form up to 28 days (Ranasinghe et al., 1999, 2003).

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