Keeping Cool--Refrigeration in Modern Life

An Absorbing Experiment

The first 2-door combination refrigerator and freezer, 1947

Description

It isn’t low temperatures alone that help to keep foods good to eat; other elements of food storage also impact freshness.

Ethylene gas is a horomone released by fruits and vegetables as they mature, or ripen. When this gas collects, it can “encourage” the produce to ripen faster, or ripen other, different produce nearby.

In this experiment, students will experiment with different storage solutions for produce, and “see” how ethylene gas collects.

Materials

Three green bananas (though other fruits/ vegetables can work, the color change bananas go through it easy to observe)

Access to a refrigerator/ minifridge

Two sealable plastic bags

An ethylene-absorbing packet (available from online retailers)

Outline

1.      Without cutting or peeling the bananas, observe how they look now. All three should start out as green/ relatively unripe. Have students draw any blemishes or bruises that they do see, so they can be tracked as the bananas change

2.      Place the bananas in the following locations:

a.      A countertop, out of the sun and away from a heat source

b.      Sealed in a plastic sandwich bag

c.      Sealed in a plastic bag with an ethylene absorbing packet

3.      As time passes, check the bananas and record/ draw any changes that are noticed. Even if nothing changes, that’s relevant!

4.      As time passes, note: which banana is ripening first? What might be influencing that?

5.      After the experiment was completed, try peeling the bananas to inspect the inside as well

Extended Activity

Adapted from https://inspirationlaboratories.com/banana-experiment/

·        Seal the green bananas in a regular sandwich bag, one per bag, alongside another piece of fruit: an apple, another banana, and orange, and a lemon. Leave them out on a counter and away from sun/ heat and in the same space. Now that factors such as bag type, location, and temperature are controlled, watch the bananas and see how they change. Which banana ripens first?