Observing colour layer on cut fruits and vegetables in Changes around Us – Class 7 Science Experiment

Chapter Name: Changes around Us

Activity Name: Observing colour layer on cut fruits and vegetables in Changes around Us

Activity Description:

Required Items:

1. Apple
2. Brinjal (Eggplant)
3. Potato
4. Tomato
5. Cucumber
6. Banana
7. Knife
8. Plates

Step by Step Procedure:

1. Take the apple, brinjal, potato, tomato, cucumber, and banana.
2. Using the knife, cut each fruit and vegetable into small pieces.
3. Place the cut pieces of each fruit and vegetable in separate plates.
4. Expose the plates with the cut fruits and vegetables to open air for some time (e.g., 30 minutes to 1 hour).

Experiment Observations:

Fruit/Vegetable	Initial Color	Color After Exposure
Apple	Red	Brown
Brinjal	Purple	Brown
Potato	White	Slightly Brown
Tomato	Red	Slightly Brown
Cucumber	Green	No Significant Change
Banana	Yellow	Brown

Note down your observations in below table format

Precautions:

1. Ensure the knife used for cutting is sharp and handled carefully to avoid accidents.
2. Use clean plates for each fruit/vegetable to prevent contamination and accurate observations.
3. Avoid touching the cut surfaces with hands to minimize any external factors that could affect the color change.

Lesson Learnt from Experiment:

The experiment will likely demonstrate that some fruits and vegetables undergo a visible change in color when exposed to open air. This change is primarily due to a process called enzymatic browning, which occurs when certain enzymes present in the fruits and vegetables react with oxygen in the air.

The browning is more noticeable in fruits like apples and bananas, as they contain an enzyme called polyphenol oxidase. When the cell structure is damaged through cutting, this enzyme reacts with oxygen, resulting in the formation of brown pigments called melanins.