2. Methods

Independent
variables: Moisture of the food piece (volume of water added), amount of light and amount of air in the container/ziplock bag (air tight vs open air).


Dependent variables: The amount of moldy patches on the bread, size of the moldy patches and the colour of the moldy patches

Equipment List:

- 6 1/2 pieces of wholemeal bread
- 3 Ziplock bag
- 3 white LED. ($2.95 each bought from RS components, RS stock No.454 4661)
- 3 UV LED. ($5.63 each bought from RS components, RS stock No.454 4396)
- 50 ml cylinder/syringe. You buy it from a pharmacy.
- Ruler/graph paper
- Gloves
- A box that doesn’t allow light to pass through
- A stand at a fix position
- Cookie cutter a small one.
- Charger thingy for plug to USB
- Thermometers. Brought from home.



How to do it?

Step 1: Get the necessary materials. 

Step 2: Take 6 1/2 pieces of bread and cut it out into 18 disks (shapes) while wearing gloves. 

Step 3: Take 6 disks of bread and moist it with 1 ml of water. 
Take another 6 disks of bread and moist it with 2.5 ml of water. 
Take another 6 disks of bread and moist it with 5ml of water.

Step 4: Take another 3 sets of 1ml,2.5ml and 5ml disks of bread and put it into ziplock bags.

Step 5: Expose one set of 1ml, 2.5ml and 5ml to 24 hours LED light.(using a lamp)
Expose another set of 1ml, 2,5ml and 5ml to no light.(using a lamp)
Expose another set of 1ml, 2.5ml and 5ml to 24 hours of UV light.(using a lamp)

Step 6: Put the bread pieces into the set-up.

Step 7: Take out the disks everyday and check the colour, size of the mold everyday.

Step 8: Measure the size of the mold using a ruler(cm)

Step 9: Tabulate the results each day.

Step 10: Throw away the bread pieces after 7 days of measuring.

Step 11: Clean-up the set up and keep the bread for further investigation of it

Step 12: Write an analysis about it.

The black box:
Made by Jia Tong
Click this for larger picture

RISKS:

1) As this experiment involves the growth of mould on bread
2) When using of LED lights and water
3) 24 hour of LED might caused overheat and fire.
4) The UV lighting may also cause the styrofoam to melt causing differences in temperature of the set-ups
5) The mouldy pieces of bread may contaminate other foods nearby

How to Manage:
1) Do not consume the mouldy pieces of bread.
2) the water can shock us if we accidentally pour it on the LED lights. Do not touch any electrical wiring or lights with wet hands.
3) Check the LED lights periodically and make sure it is doesn’t overheat.
4) make sure to keep the bread pieces away from any food.



How to record results:

1.    Tabulate the size of the mould. Occasionally we will take out the disc and check how far deep the mould has grown inwards. 
2.  We would overlay some tracing paper on the mold, trace the shape, and then overlay the tracing paper on some graph paper, and count the squares.
2.    Plot a table of how the different amount of water, type of lighting in a table that would  affect the size, colour and depth of the mold.
3.    From the table we can find out the best way to preserve food over a long period of time such as using what types of light, amount of water and what kind of air environment.
4. This is the table for filling it up


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