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Degreening Navel Oranges

The word degreening simply means to get rid of the green colour. As much as this procedure is simple in its basis and principles, as much as it is complicated in its application.

Principle
In the month of October, which is the very beginning of the season, some Navel oranges in Egypt reach good pleasant taste whereas they are still green. The green colour is not attractive to the consumers.  This is because consumers know that green oranges are mostly immature.   In order to convince consumers at that early time that there are tasty Navel oranges, the color must be changed from green to orange.  This is done by degreening them.
 
Coloration on the trees and coloration by degreening
To understand the difference, we must know first why the Navel turns in the nature from green to orange colour.  In simple words, the weather is the cause.  There are some optimum weather conditions which make the ignition of the coloration.  But these most favorable weather conditions are present in the nature for only few hours during the day.  This is why on the trees, the Navel orange turns from green to orange colour very slowly in a month and more. In the degreening process, these most favorable weather conditions for natural coloration are kept 24 hours per day.  When the Navel oranges are exposed all the time to these best weather conditions all the time, they naturally turn their colour from green colour to orange colour within few days. 
 

How the degreening process is done
Degreening rooms are the equipment used for the process.  These rooms are totally insulated from the outside world. Green Navel oranges are stacked in these rooms. Parameters of the optimum weather conditions for turning the colour from green to orange are then regulated, kept, and monitored around the clock. 
The main parameters are:

  1. Temperature
  2. Humidity
  3. Oxygen level
  4. Carbon dioxide level (CO2)
  5. Ethylene level
 Is the degreening room all what we need to degreen Navel oranges?
Of course not.  What is done in the fields is not less important than what is done in the degreening rooms.  Not all the Navel oranges will respond equally to the degreening process.  This is why we must choose the best reacting oranges to the process.  This is done by monitoring all what is done in the fields 6 months before the degreening season.  Most important parameters to be verified in the fields are:
  1. Origin of the shoots and their variety
  2. Age of the trees
  3. Irrigation program
  4. Fertilization program
  5. Soil humidity
  6. Soil composition
  7. Weather conditions throughout the year

How do we know that we can start the degreening season?
The idea is that we can make the colour of the fruit attractive to the consumer by degreening it but, we can do nothing about the taste.  This is why, we never start the degreening season before we make sure that the taste is good.  This is done in our laboratory by analysis called maturity tests.  When the analysis show that the fruits of a certain field have reached the permissible maturity index, we can start the degreening process at once.  If the fruits of another field do not reach the satisfying maturity index,  the degreening process of this field is postponed until it gets the right maturity state. The main parameters of the maturity index which shows how good the taste, are:

  1. Juice content
  2. Acidity level
  3. Sugar level
  4. Solids level diluted in the juice
What are the challenges of the degreening process?
When we command well the degreening process, it turns to be an art and not a science.  The challenge is to get the beautiful deep orange colour in the minimum number of days.  This is encountered with a lot of hazardous things which the most important of them are:
1- Decay: 
The optimum weather conditions in which the fruit is kept in the degreening room are also the most favorable conditions to decay the fruit.  We use special sophisticated procedures to prevent this from happening.
2- Dark green spots: 
This is called oleocellosis.  The green fruit peel is very sensitive to the shocks.  The least friction or shock make a rupture in the peel.  This injury spreads and make a spot which do not degreen in the degreening room.  The result is ugly blemished peel. We invented an exclusive State-of-the-Art equipment to prevent fruits from this defect. This process which we developed throughout the years is giving the perfect quality.
 
Why our degreened fruits are the best that you can get?
Because we guarantee:
  1. Good taste
  2. Beautiful orange colour
  3. No skin defects
  4. No decay
  5. Longer shelf life
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