1. Investigating how different atmospheres affect iceberg lettuce pinking

2. What do they all have in common?
All of these images show oxidation reactions: rusting; lettuce pinking and butter turning rancid.
Acknowledgements
C026/1295
H110/0771

3. Objectives To recall the common gas tests;
To investigate safely how different gases affect pinking of iceberg lettuce;
To suggest methods for increasing the shelf life of iceberg lettuce.
Acknowledgements
Please link shelf life to waste reduction in the home – if MAP is used it’s in the consumer pack so it’s only that part of the supply chain which benefits.
Shelf life is defined the period during which the product maintains its microbiological safety and sensory qualities at a specific storage temperature

4. Comparing the gas tests
Hydrogen Carbon dioxide Oxygen
Lighted splint:
Hear a Pop!
Limewater changes from colourless to cloudy
Glowing splint:
Relights
Video clip that you may wish to use:
Acknowledgements
C017/7770
C010/9637
C023/3026

5. Investigation
Cut iceberg lettuce will turn pink. How can we increase its shelf life?
You are going to investigate how different gases affect the pinking of iceberg lettuce
Note that it’s particularly iceberg lettuce that pinks

6. What have we found out? Look at your results table
Is the pinking of iceberg lettuce affected by the type of gas that it is stored in? Why might this be so?
Extension:
How does this relate to the prepared salad industry?
This relates primarily to prepared salad containing iceberg lettuce.

7. Reflection Describe the tests for: Hydrogen gas Carbon dioxide gas
Oxygen gas?
Explain the causes of iceberg lettuce pinking?
Describe how iceberg lettuce pinking can be reduced?