“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 SugarDepending on their ripening behaviour, fruits are classified into: CLIMACTERIC FRUITS NON-CLIMACTERIC FRUITS
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
Some examples of climactericfruits Banana Plum Mango Fig Passion fruit Papaya Guava Pear Climacteric fruits
NON-CLIMACTERIC FRUITSOnce harvested, these fruits donot ripen further. In order to attain full ripenessand flavor, these fruits areoften harvested once they havefully ripened.Thus have a short shelf life ifharvested when they are ripeSome examples Oranges Cherry Grapes Strawberry
WHY CONTROLLED FRUIT RIPENING IS BEING FAVOURED NOWADAYS ? Assures good shelf life. Assures good shelf life. Provides excellent fruit appearance. Provides excellent fruit appearance. Provides optimum eating quality. Provides optimum eating quality. Fruit is available when and where required. Fruit is available when and where required.
THE 4 MAJOR FACTORS OF COMMERCIAL RIPENING 4 major factors AdequateEthylene Air gas circulation Temperature RH control control
1. ETHYLENE GAS• Colorless gas, slightly sweetOdor & soluble in water.• Normally produced during bananaripening.• Governs senescence & ripeningprocesses.• 1 ppm is sufficient for ripening but1000 ppm is frequently used.• concentration of ethylene gas higherthan 2.7% (27,000 ppm) ) can beexplosive.
2. TEMPERATURE CONTROL (PULP T C) 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.
Too high- High- irregular rapid ripening of Optimum- ripening, fruits, poor 15 C - 18 C difficult to keeping Low- control; poor quality slow appearance (>18 C ) ripening/ (dull grey- possibly green) &Too low- slight taste flavorchilling degradationinjury (<12 C )
3. RELATIVE HUMIDITY (RH) CONTROL 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%
4. ADEQUATE AIR CIRCULATION Assures uniformity of ripening and prevents buildup of CO2. Air circulation fans operate continuously while ripening fruit. Air circulation fans Fruit boxes are stacked to allow air circulation. 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
Ethylene(catalyst) Green bananas in Room is closed & discharged at a cartons are loaded refrigerated for 12-16 concentration of 0.1%-into ripening rooms hrs until pulp temp 0.04% (100-400ppm) Fruit pulp temp: reaches 15-17 C RH: 90% ≈14 C RH: 90% Room is kept close for 24hrs Room is closed again, atmosphere is controlled At the end of this Room is at a temp of 15-17 C for time, room isventilated & ripe 3-4 days ventilated to clear fruit removed RH: 75% ethylene & co2 gas Extractor fans may be used Fruit pulp may reach a temp of 32 C during this process 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 methodsSingle shot of gas, Continuous slow trickle ofgiven at one time. gas into the room for 24 hrs.A method to monitor ethylene concentration should beavailable.
BASIC PRINCIPLES OF BANANA RIPENING ROOMS. Insulation. Refrigeration. Heat. Air tight. Controllable vents for ventilation. Humidifiers. Sanitary. 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.
METHODS OF INTRODUCING ETHYLENE GAS •a liquid concentrate Catalytic Generators Ethy-Gen is decomposed in an electrically •Each ethylene •The explosion powered cartridge risk from Ethylene/Nitrogen Ethylene and Cylinders Ethylene Cartridges catalytic contains ethylene can generator, to be eliminated approximately produce 51g of pure by the use of a ethylene gas. ethyl mixture of gas •The Ethy--Gen a consisting of concentrate is •Ethylene is released by 5% ethylene in supplied in containers which piercing the nitrogen. produces about cartridge with 12 ft3 (0.33 m3 ) a tool which is of ethylene gas. supplied.
Ripening indicatorIodine (I) can be used to determine whether the fruitis ripening or rotting by showing whether starch inthe fruit has turned into sugar. For example, a drop ofiodine on a slightly rotten part (not skin) of a bananawill turn a dark-blue or black color, since starch ispresent. If it stays yellow, then most of the starch hadconverted to sugar.
Alternate ripening method 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.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 chartevenly green; common trace of light green/ yellow-flecked with brown ; yellow; colour of greenmore yellow than yellow-fully fungus effected colour after more than green tip- ideal all over ripe ripe colour yellow; ready for green; bananas treated by harvesting for sale bananas ready for banana gas wholesale supply recommended for consumption retail outlets
A RIPENING SCHEDULE FOR BANANAS Ripening 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.
Fire/Explosion by spillage/ uncontrolled use of ripening gassesHAZARDS Toxicity & Asphyxiation by o2 deficiency& co2 accumulation
CONCLUSION D eat-ripe& senescence phase C ripening phase ClimactericPreclimacteric B A phase phase Preclimacteric phase Days after harvest
REFERENCEControlled Ripening of Some Fruits,FoodRecapRipening - Wikipedia, the free encyclopediaBanana ripening, ISOPAN INSULATION PVT LTD/PDFAIC ripening protocol/PDFFruit ripening by Prof S.N. Naik 2T Delhi/PDFRipening bunch management, Dr Scot Nelso, plant pathologist,University of hawaii/ PDFThe ripening of bananas, Interko B.V/PDF