Fruit Storage Techniques and Conditions

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Questions and Answers

What is the primary effect of scrubbing ethylene from the storage air for bananas?

It increases the ripening process.

It enhances the flavor of bananas.

It delays the ripening process. (correct)

It reduces the shelf life of bananas.

What is the average shelf life of bananas when ethylene is scrubbed from the storage air?

Two to three weeks.

Four to six weeks. (correct)

Six to eight weeks.

One to two weeks.

Which apple cultivar requires the lowest oxygen level for optimum storage?

Fuji (correct)

Granny Smith

Gala

Braeburn

What is the ideal storage temperature range for the Braeburn apple?

6-9 °C Signup and view all the answers

Among the listed apple cultivars, which one has the highest CO2 percentage requirement?

Idared Signup and view all the answers

Based on the averages for apple storage, what is the mean CO2 percentage for all cultivars listed?

2.0% Signup and view all the answers

Which apple variety should be stored at the lowest temperature?

McIntosh Signup and view all the answers

What is the required CO2 percentage for storing the Granny Smith apple?

2.0% Signup and view all the answers

What is the recommended storage temperature range for pears?

-1 to 0 °C Signup and view all the answers

Which pear variety is recommended to be stored with 1-2.5% O2 and 0-0.5% CO2?

Anjou, d’Anjou Signup and view all the answers

Which CA disorder is associated with the Bartlett pear variety?

Core flush (CF) Signup and view all the answers

What is the CO2 concentration for the Blanquilla pear variety?

3% Signup and view all the answers

Which pear variety has a storage recommendation of 3-5 months?

Bartlett Signup and view all the answers

What is a primary purpose of controlled atmosphere storage?

To modify the composition of air during storage Signup and view all the answers

Which method is used to decrease oxygen levels in controlled atmosphere storage?

Purging with nitrogen Signup and view all the answers

What is recommended to manage carbon dioxide levels in a CA storeroom?

Employing a molecular sieve scrubber Signup and view all the answers

How should hydrated lime be stored to maximize effectiveness in CO2 absorption?

On shelves allowing adequate air circulation Signup and view all the answers

Which of the following is NOT a method to increase carbon dioxide levels?

Implementing a hydrated lime scrubber Signup and view all the answers

What is the recommended ratio of hydrated lime used to treat air for every 100 kg of fruit?

0.6 kg Signup and view all the answers

Why should lime bags be only partially filled during storage?

To prevent hardening of the outer layer Signup and view all the answers

What is the function of a scrubber in controlled atmosphere storage?

To react with CO2 and remove it from the air Signup and view all the answers

How much lime is recommended per metric ton of apples to keep CO2 below 2% during storage?

12 kg Signup and view all the answers

Which of the following materials can be used for ethylene control to decrease its levels?

Potassium permanganate Signup and view all the answers

What thickness of polyethylene sheeting is recommended for creating plastic tents for controlled atmosphere storage?

7 to 8 mil Signup and view all the answers

What is a recommended method to achieve a better gas barrier at the floor of a controlled atmosphere tent?

Placing wood panels over a plastic sheet Signup and view all the answers

Which component is used in a controlled atmosphere tent to circulate the storage air?

A small fan Signup and view all the answers

What primary advantage does using a plastic tent provide for controlled atmosphere storage?

Economical and flexible setup Signup and view all the answers

What is the typical concentration of CO2 desired in a controlled atmosphere for produce storage?

5% Signup and view all the answers

How is a seal created between the tent plastic and the floor plastic in a controlled atmosphere setup?

Using tape Signup and view all the answers

Study Notes

Bananas

Bananas can be stored for four to six weeks at ambient temperatures if ethylene is removed from the storage air.

Apples

Apples are commonly stored using controlled atmosphere (CA) and modified atmosphere (MA).
The average optimum levels for apple varieties include 1.7% oxygen, 2% carbon dioxide, and 0.9°C for optimal storage.
Different apple varieties have different optimal storage conditions, and their storage time can vary significantly.
Braeburn can be stored for 6-9 months while Red Delicious can be stored for 6-11 months.

Storage Techniques

CA and MA storage complements appropriate temperature and humidity management.
It's important to monitor and control the air coming into and circulating within the storage room.
Oxygen can be decreased through purging with nitrogen obtained from liquid nitrogen, membrane systems, or molecular sieve systems.
Carbon dioxide can be increased using dry ice or pressurized gas cylinders.
Carbon dioxide can be decreased using molecular sieve scrubbers, activated charcoal scrubbers, sodium hydroxide scrubbers, and hydrated lime scrubbers.
A simple hydrated lime scrubber (Calcium carbonate) can regulate CO2 levels in a CA room.
The scrubber should contain enough lime for the entire storage period, with new lime added if CO2 absorption declines.
Lime with a smaller particle size (fine mesh) is more efficient at reacting with CO2 than lime with a coarse mesh.
To maximize effectiveness, lime should be packaged in partially (50%) filled bags, stacked on a pallet with shelves to allow air circulation.
Approximately 12 kg of lime per metric ton of apples is recommended for 3 to 4 months of storage to keep CO2 below 2%.

Ethylene Control

Ethylene can be decreased using potassium permanganate, activated charcoal, and catalytic oxidation.
A simple scrubber can be added to the air supply line to prevent ethylene buildup.

Storing Pallet Loads

Pallet loads of produce can be stored using a semi-permanent plastic tent setup for creating a gas seal.
A sheet of 4 to 5 mil polyethylene on the floor covered with wood panels provides a better gas barrier.
The seal is made by joining the tent plastic with the floor plastic using tape.

Storing in Refrigerated Warehouses

Controlled atmosphere (C.A.) tents can be constructed using 20 mil polyvinyl chloride (PVC) sheeting suspended over traditional pallet racks inside refrigerated cold storage warehouses.
The tents can be sealed by closing zippers and immersing the bottom of the door and adjacent floor panel in a trough of water.

Bananas Storage

For green bananas, a low-cost plastic tent made from clear polyethylene sheeting can be used for controlled atmosphere storage.
A small fan circulates the CA storage air (2% O2 and 5% CO2) through a chamber of potassium permanganate on aluminum oxide (Purafil).

Pears

Ideal storage temperature for pears is –1 to 0 ° C, unless otherwise indicated.
Different pear varieties require different levels of oxygen and carbon dioxide for optimal storage.
Some common CA disorders include internal breakdown/browning, brown heart, pithy brown core, core flush, cavity, and chilling injury.

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Description

This quiz explores the storage techniques for bananas and apples, including controlled atmosphere and modified atmosphere methods. Understand the optimal conditions for various apple varieties and how to manage storage environments effectively. Test your knowledge on the science behind fruit storage!