Post on 19-Jan-2015
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“CONTROLLED FRUIT RIPENING WITH EMPHASIS
ON BANANA RIPENING”
ANUSHA BABOOA
What is Fruit Ripening?A process where the fruits become edible. They become sweeter, less
green & soft.
One of the most accepted definitions describe the fruit ripening as a physiological process involving the induction/
acceleration of a variety of metabolic processes most or all enzymatically regulated and catalyzed.
Starch Sugar
Depending on their ripening behaviour, fruits are classified into: CLIMACTERIC FRUITS NON-CLIMACTERIC FRUITS
They enter climacteric phase after harvest, that is they continue to ripen although off tree.
Most ripened climacteric fruits are too soft and delicate to withstand transportation & handling.
The ripening process is considered irreversible in climacteric fruits
CLIMACTERIC FRUITS
Some examples of climacteric fruits
Banana Plum Mango Fig Passion fruit Papaya Guava Pear
Climacteric fruits
Once harvested, these fruits do not ripen further.
In order to attain full ripeness and flavor, these fruits are often harvested once they have fully ripened.
Thus have a short shelf life if harvested when they are ripe
Some examples Oranges Cherry Grapes Strawberry
NON-CLIMACTERIC FRUITS
Assures good shelf life.
Provides excellent fruit appearance.
Provides optimum eating quality.
Fruit is available when and where required.
WHY CONTROLLED FRUIT RIPENING IS BEING FAVOURED NOWADAYS ?
Assures good shelf life.
Provides excellent fruit appearance.
Provides optimum eating quality.
Fruit is available when and where required.
THE 4 MAJOR FACTORS OF COMMERCIAL RIPENING
Ethylene gas
Temperaturecontrol
RHcontrol
AdequateAir
circulation
4 major factors
• Colorless gas, slightly sweetOdor & soluble in water.
• Normally produced during banana ripening.
• Governs senescence & ripening processes.
• 1 ppm is sufficient for ripening but 1000 ppm is frequently used.
• concentration of ethylene gas higher than 2.7% (27,000 ppm) ) can be explosive.
1. ETHYLENE GAS
Inadequate T◦C control can decrease the shelf life of bananas (good for 4 days only at T◦C > 23).
Actual temperature used depends on when you want the fruit ready.
2. TEMPERATURE CONTROL (PULP T◦C)
Too low- chilling injury (< 12◦C )
Low- slow ripening/ possibly slight taste degradation
Optimum- 15◦C - 18◦C
Too high- irregular ripening of fruits, poor keeping quality (>18◦C )
High- rapid ripening, difficult to control; poor appearance (dull grey-green) & flavor
Deficiency:
skin color, freshness may be affected and may cause splitting, weak necks, breaking, weight loss and may cause existing blemishes to become enhanced.
Begin ripening:
90% RH (use automatic humidifiers with humistats control)
Color break:
Reduce RH to 75%
3. RELATIVE HUMIDITY (RH) CONTROL
Assures uniformity of ripening and prevents buildup of CO2.
Air circulation fans operate continuously while ripening fruit.
Fruit boxes are stacked to allow air circulation.
4. ADEQUATE AIR CIRCULATION
Air circulation fans
Boxes
Many stacking patterns are available, but a 4-inch air channel is ideal.
Rule of thumb
The discharge from the centrifugal blower in cubic feet per minute should equal the cubic capacity of the ripening room.
centrifugal blower
RIPENING PROCEDURE taking BANANA as an example
Green bananas in cartons are loaded into
ripening roomsFruit pulp temp:
≈14◦C
Room is closed & refrigerated for 12-
16 hrs until pulp temp reaches 15-
17 ◦C RH: 90%
Ethylene(catalyst) discharged at a concentration of
0.1%-0.04% (100-400ppm)
RH: 90%Room is kept
close for 24hrs
At the end of this time, room is ventilated to
clear ethylene & co2 gas
Room is closed again, atmosphere is controlled at a temp of 15-17 ◦C for 3-4
daysRH: 75%
Fruit pulp may reach a temp of 32 ◦C
during this process
Room is ventilated &
ripe fruit removed
Extractor fans may be used
Amount of ethylene gas required for ripening room is normally calculated on the free air space after the
bananas have been loaded (i.e., if bananas take up to 35% of the room size, calculate the amount of ethylene
required for remaining 65% free air space)
Ethylene gas from compressed gas cylinders:2 methods
Single shot of gas,given at one time.
Continuous slow trickle of gas into the room for 24 hrs.
A method to monitor ethylene concentration should be available.
Insulation. Refrigeration. Heat. Air tight. Controllable vents for
ventilation. Humidifiers. Sanitary.
BASIC PRINCIPLES OF BANANA RIPENING ROOMS.
Humidifiers.
Simple banana ripening room
Plywood walls and roof ;insulated
Compressor (air conditioner) on top
Cement floor
Temperature, ventilation and humidity controls
Note: it is best to have at least three : ripening rooms, instead of just one.
It is also possible to convert existing rooms or structures into banana ripening rooms, depending on scale.
Primitive
Traditional
(standard cold rooms with openly stacking of boxes)
Modern
( so-called pressure-ripening)
Ripening systems
Catalytic G
enerators
• a liquid concentrate 'Ethy-Gen' is decomposed in an electrically powered catalytic generator, to produce ethylene gas.
• The 'Ethy--Gen' concentrate is supplied in containers which produces about 12 ft3 (0.33 m3 ) of ethylene gas.
Ethyle
ne Cartri
dges
•Each ethylene cartridge contains approximately 51g of pure ethyl•Ethylene is released by piercing the cartridge with a tool which is supplied.
Ethylene and
Ethylene/Nitrogen Cylinders
•The explosion risk from ethylene can be eliminated by the use of a mixture of gas a consisting of 5% ethylene in nitrogen.
METHODS OF INTRODUCING ETHYLENE GAS
Iodine (I) can be used to determine whether the fruit is ripening or rotting by showing whether starch in the fruit has turned into sugar. For example, a drop of iodine on a slightly rotten part (not skin) of a banana will turn a dark-blue or black color, since starch is present. If it stays yellow, then most of the starch had converted to sugar.
Ripening indicator
Calcium carbide chemical used for the production of
acetylene gas during gas welding. Ethrel (brand name) phosphonic acid that produces ethylene gas
and is known to trigger the process of fruit ripening.
Ethepthon (2-chloroethylphosphonic acid) a plant growth regulator known to penetrate
into the fruit and decompose to ethylene.
Alternate ripening method
These ripening agents have been banned in many countries due to their harmful effects. The most effective and widely used ripening
agent nowadays is ethylene
Banana colour chart
evenly green; common colour
afterharvesting
light green/ trace of yellow;
colour of bananas
treated by gas
more green than yellow; ready for wholesale supply
more yellow than green;
recommended for retail outlets
green tip- ideal colour for sale
all yellow-fully ripe bananas ready for
consumption
yellow-flecked with brown ; over ripe fungus effected
banana
A RIPENING SCHEDULE FOR BANANASRipening time is from hard green to Color Stage 4
( Green-yellow with dark green tips)
Bananas are ripened to color stage 3 or 4 depending on mode of retailing for dispatch to market.
Depending on cultivar and market requirements, ripening cycle maybe spread from 4 to 8 days.
HAZARDSFire/Explosion by
spillage/ uncontrolled use of ripening gasses
Toxicity & Asphyxiation by o2 deficiency& co2
accumulation
Preclimacteric phase
CONCLUSION
Days after harvest
A B
C
D
Preclimacteric phase
Climacteric phase
ripening phase
eat-ripe& senescence
phase
Controlled Ripening of Some Fruits,FoodRecap
Ripening - Wikipedia, the free encyclopedia
Banana ripening, ISOPAN INSULATION PVT LTD/PDF
AIC ripening protocol/PDF
Fruit ripening by Prof S.N. Naik 2T Delhi/PDF
Ripening bunch management, Dr Scot Nelso, plant pathologist, University of hawaii/ PDF
The ripening of bananas, Interko B.V/PDF
REFERENCE
Thank you for your kind attention…