7/28/2019 Preservation of Bananas for Ripening by MA Packaging

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Prepared by : F. Reid

Preservation of Bananas for Ripening

Options to be tested

Option 1

VACUUMPACKAGING OFBANANA

1. Function : To pack and store the stage 2 ripened bananas inmodified atmosphere packaging in an attempt to delayripening for up to 5 days when stored at 20 o C.

2. Specification :(a) Overall bagdimension : Box liner dimension will be 38 in. (W) x 60 in. (L)(b) Structure/ BagType : Amcor Lifespan vacuum bag (see information below)(c) Power required : The Horse Power for the vacuum packaging machine/

vacuum pump.3. General Information : Bananas usually ripen in three to five days after

harvesting. We aim to delay ripening of fruits for anadditional 5 to 7 days by vacuum packaging.

At the pack house the matured banana hands arepackaged in a box lined with a polypropylene sleeve/bag. Using a vacuum or suction device the air/ oxygensurrounding the bananas is removed and the bagsecured.

The bananas are stored under vacuum for 24 hrs at 14o C after which the vacuum is removed when air is re-introduced.

Bananas are gassed and ripened to stage 2 and thenthe vacuum is restored for 24 48 hours. The vacuum

7/28/2019 Preservation of Bananas for Ripening by MA Packaging

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Prepared by : F. Reid

is again removed 1 day before the bananas are sold.This will re-trigger ripening to stage 3 within 4 to 5days of storage at 20 o C. No further gassing is needed.

4.

Cost of the unit, etc.,

:

(Cost of the vacuum packaging machine), cost forLifespan polypropylene bags.5. Cost of operation : Additional labour cost for machine operator

6. Salient features ofthis method : The vacuum packaged green banana can bestored without ripening up to 21 days if no

ripening is needed for long periods. The quality is not affected.

7. Disadvantages of the method 1. Double handling of bananas before and after

ripening can cause bruising. 2. Only small quantities of bananas can be vacuumedas the process is an additional step in the pack house operations

Introduction to Lifestyle Modified Atmosphere Packaging

At the time of sealing, the internal atmosphere is air and the produce is respiring at the (higher) rate

associated with air. However, the LifeSpan package has been designed for a lower respiration rate that

exists under a modified atmosphere.

Also, initially there is no gas concentration difference across the wall of the LifeSpan package - there is

air on both sides. Hence there will be no transfer of oxygen into the package and no transfer of carbon

dioxide out of the package.

Respiration by the banana uses up oxygen within the headspace of the LifeSpan package and the

oxygen level will begin to decline from 20.9%. Respiration by the banana releases carbon dioxide into

the headspace of the LifeSpan package and the carbon dioxide level will begin to rise from 0.03%. The

atmosphere is modifying passively. The rate of modification is high at first, but as it continues, the

modified atmosphere will start to suppress respiration rate. At the same time, there is a growing

concentration difference for each gas across the wall of the LifeSpan package. Hence there is an

increasing rate of gas diffusion through the walls.

In an ideal situation, the rate at which the atmosphere modifies will slow with time and eventually theMA will stabilize at the designed values for oxygen and carbon dioxide. In practice, the MA quite often

overshoots the designed values and then drifts back to the long term equilibrium MA. This occurs as themodification happens at a rapid pace and there is a substantial lag in the change in respiration rate.It is important that this passive modification is monitored in development trials to ensure anyovershoot does not switch the produce into anaerobic respiration.