Ripening of Fruits complete document

1. Fruits Ripening
Chambers
Prepared By: Jahanzaib Ahmad (Refrigeration Engineer)
Organization: Winrock International

2. What is ripening?
• Ripening is a process in that fruits that makes suitable for
consumption. The fruit become sweeter and softener.
• During ripening starch is converted to sugar.
• The fruit is said to be ripe when it attains its full flavour and aroma.
• Ripening causes colour change in the fruit.
• Based on ripening behaviour, fruits are classified as
• Climacteric
• Non-Climacteric

3. Climacteric Fruits
• Fruits shows dramatic increase in the rate of respiration during
ripening and well respond to ethylene for ripening.
• Mango, Apple, Banana, Tomato

4. Non-Climacteric Fruits
• Fruits do not show dramatic increase in the rate of respiration during
ripening and do not respond to ethylene for ripening.
• Watermelon, Pineapple, Citrus, Grapes

5. Chemical Ripening Process
Unripe Fruit
H₂C=CH₂
(Ethylene)
Genes
(For enzyme synthesis)
Producing
Enzymes
Degrade
Parts of fruit
(Chlorophy II, acids, Starches,
pectin, proteins etc.)
Produces
Resulting in
Increasing
H₂C=CH₂
(Ethylene Artificial)

6. Ripening Methods
• Ripening by using Calcium carbide
• Calcium carbide is used in some countries for artificially ripening fruit.
When calcium carbide comes in contact with moisture, it produces acetylene
gas, which is quite similar in its effects to the natural ripening agent, ethylene.
• Calcium carbide treatment of food is extremely hazardous because it contains
traces of heavy metal arsenic and phosphorous.
• Ripening by using Artificial Ethylene gas
• Ethylene gas is commercially used to ripen fruits after they have been
picked. Fruits, such as tomato, banana, and pear are harvested just
before ripening has started (typically in a hard, green, but mature stage). This
allows time for the fruit to be stored and transported to distant places.
• Ethylene is highly flammable gas, but safe for human health.

7. Avoiding Exposure to Excessive Ethylene
• Removal of excessive ethylene from Storage chamber
• Use of adequate air changes
• Use of ethylene absorber
• Potassium permanganate (Alkaline KMnO4 on inert pellets “Ethysorb” etc).
• Activated and Brominated Charcoal +/- KMnO4 = “Stayfreash” absorber.

8. Major factor for commercial fruits ripening
• Temperature Control
• RH Control
• Ethylene Gas
• Adequate Air circulation
• Ventilation
Fruits
Ripening
Temperature
Control
RH Control Ethylene Gas
Air
Circulation
Ventilation

9. Temperature Control
• Refrigeration Equipment
• Evaporative Unit
• Condensing Unit (Air Cooled)
• Accessories

10. Relative Humidity Control
• Industrial Humidifier
• High humidity improves quality by
adding moisture to the fruit, reduces
cracking and bruising, and slows
down the ripening process to extend
shelf life.
• It can be different size and capacity
as per design requirement.

11. Ethylene Gas
• Ethylene gas generator
• An external ethylene application
will trigger the proper ripening
process to begin, which includes
the fruit producing internal ethylene.
• It can be different size and capacity
as per design requirement.

12. Adequate Air circulation
• Open Air Circulation
• Air Path
• Air Bags (Vertical Air Circulation)
• Air Ducts

13. Ventilation System
• Ventilation by doors opening
• Manual ventilation system (Exhaust Fans)
• Automatic Ventilation System (PLC Control)

14. Types of ripening chambers
Traditional cold storage room type Room designed with specified air path

15. Types of Controls
Manual Operating System Automatic Operating System

16. Types of Evaporators
Front discharge Bottom discharge

17. Types of Insulated Doors
Manual Hinged Door Manual Sliding Door

18. Types of Floor
RCC Checkered

19. Types of Refrigerants
Freon Ammonia
It can be use in relatively small refrigeration systems It can be use in large refrigeration systems

20. Pro & Cons of Different Ripening Chambers
Traditional cold storage room type
• Pros
• Simple Design
• Less installation cost
• Less maintenance cost
• May be use manual stackers
• Cons
• More land required
• Most chances of human error
• Max. human resources required
• Mostly Single stage stacking possibility
• High operating cost
Room designed with specified air path
• Pros
• Automatic controlling system
• Less chances of human error
• Less operating cost
• Suitable for Multi stacking
• Equality in ripening of fruits
• Less land required
• Cons
• Compact design
• High installation cost
• Electric stacker is compulsory