| The harvesting season |
When the persimmon has its own color,
pick well-ripened persimmons first. You have to consider a climate
condition, because of a heavy frost in late autumn. If a persimmon
suffers from a heavy frost, you cannot store it for a long time. For
a long storage, pick persimmons which have strong flesh before they
are ripen.
|
| Harvesting process |
| It is desirable to pick the persimmons
one by one with a harvesting scissors. If a persimmon is not handled
carefully, it is bad for storage. Cut the stems shortly and use a
strong container when you move them. Especially, be careful of vibration
or impact when you move persimmons by monorail. |
| Precooling and drying |
| A persimmon breathes continually after
picking and it reduces nutritious value and lowers its quality. To
keep its best quality, check the fruit's respiration by lowering the
inside temperature of the fruit, and it means 'precooling'. Half cooling
time of persimmons is 50 minutes and it takes 4 to 5 hours to lower
the temperature to 2 to 3 degrees.
The respiration amount of a persimmon at 20 degree
is 20 to 24mg/㎏/h, but it is decreased at 4 degrees with 6mg/㎏/h.
To keep from other damage by moisture, wrap them with PE paper at
the low temperature after precooling. If you had a bad condition
for precooling, you have to predry them for storage. If the persimmon
is predried, it would become resistant to damages and keep from
getting moldy by removing its moisture.
|
| Selecting |
| After precooling and predrying, the
persimmon is sold in the market or stored after being divided by its
color and weight except injured persimmons, softened persimmons. Choose
middle sized, ripened persimmons or unripened persimmons for long
storage and if the persimmon has any damage, it is easily softened
or rotten by mold, so you have to sell them eariler. |
| Wrapping |
| Persimmons are so weak to store, so
a low temperature storage method is generally used by LDPE film wrapping
in a thickness of 0.06mm. But the paper which is used in the market
is under 0.06mm thick. Its transmissivity can be changed by a damage
in the paper from the uncareful handling and loose wrapping and it
is the cause of damage. |
| Polyethylene film
wrapping |
| Polyethylene film wrapping uses the
merits of CA storage and makes up for the weak points of it. Put 3
to 5 sweet persimmons in the polyethylene film bag which is 14cm wide
and 28cm long and store at 0 degree. It is proper to store persimmons
in 0.06mm wide polyethylene film bag, keeping the 4 to 8% oxygen content
of the air and the 5% carbon dioxide content of the air.
The amount of oxygen is reducing and carbon dioxide
is increasing in the bag by the respiration of the fruit, but the
proper density is kept by control of film. But while the persimmons
are distributing, the bag contains too much carbon dioxide and little
oxygen by increasing of fruit's respiration at the high temperature.
It is necessary to develop more proper film for distribution at
the change of temperature.
|
|
|
10day
out of a warehouse
|
|
20day
out of a warehouse
|
|
30day
out of a warehouse
|
|
|
kind
of experiment
|
decrease
rate(%)
|
Fruit
|
Quality
|
decrease
rate(%)
|
Fruit
|
Quality
|
decrease
rate(%)
|
Fruit
|
Quality
|
|
distribution
in the bag
|
0.5
|
no
change
|
Excellence
|
0.7
|
no
change
|
Excellence
|
0.7
|
no
change
|
Excellence
|
|
distribution
without bag
|
2.3
|
no
change
|
Excellence
|
6.7
|
softened
|
good
|
13.5
|
softened
|
badness
|
| Freezing wrapping |
| Frozen persimmons are suitable for long
storage. Divide a persimmon into 4 parts and freeze at -25 degrees,
wrapping with a polyethylene film bag. Three months later, it is worthless
as a fresh fruit because its flesh is softened, but it has a good
flavor in the frozen or half-melted situation.
For the freezing wrapping, use Paeng-haek-mu which
has soft flesh. A proper storage temperature is -20 to -30 degrees
and a persimmon can go bad at -2 to -3 degrees even though it is
frozen.
|
|
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