SIP Experiment - FINAL

I conducted the experiment, the final one! I improved on the way I conducted the experiment using the tips given by Ms Tan. Here are the results, the pictures speak for themselves:

Control slice

After 10 minutes

After 20 minutes

After 30 minutes

After 40 minutes

After 50 minutes

After 1 hour

After 1 hour 10 min

After 1 hour 20 min

After 1 hour 30 min

After 1 hour 40 min

After 1 hour 50 min

After 2 hours

Set-up of experiment

Consultation with Ms Tan

Yesterday, I had a consultation session with Ms Tan, my Science teacher. It was a most fruitful session, and I picked up many tips about how to improve my experiment!

Experiment

1. My control should be the one in tap water, and not the one exposed to air since all the other peaches were immersed in a kind of liquid.

2. It is better to record the appearance of the peaches at regular intervals e.g. after every 10 min, instead of my earlier design, which was to record their appearances at 5 minute intervals for half an  hour (6 times), then at 15 minute intervals for the next 1 hour (4 times), then at 30 minute intervals for the next 2 hours (4 times).


3. When I take pictures, the curtains must be closed and only artificial light should be used to regulate the amount of light the peaches are exposed to so that the pictures of the colour of the peaches will be accurate.


4. I need to use photoshop to record their HSB values (Hue, Saturation, Brightness). This can be obtained by using a colour picker to pick a specific spot on the peaches.


5. The second part of the experiment is no longer necessary.


Anyway, here are the pictures of Part 2 since I have already conducted the experiment!

Experimental set-up

Control slice (bad photographic skills)

Peaches taken out after 15 minutes of soaking

SIP Tentative Methodology (Part 2)

Materials needed:

• 3 plastic transparent cups
• 10 small paper plates
• 3 plastic spoons
• Marker
• Juice extractor
• Knife
• Stopwatch 
• Measuring Cylinder

Materials for liquids:

• 100 ml Tap Water + 1 teaspoon of salt
• 2 Lemons
• 3 Limes
• 1 peach (cut into 10 equal slices)

Method:

1. Label all plates and cups with a marker. Arrange everything on the table, such that there are 3 rows of 3 sets of plates

2. Squeeze the fruits using the juice extractor and pour the juice into the cups. Prepare the salt water.

3. Cut the peaches into 10 equal slices. Drop 3 slices into each liquid, making sure all 3 slices are fully submerged in the respective liquids. Place the final slice on the control plate.

4. Start the stopwatch immediately when all the peach slices are in the liquid. 
5. After 5 minutes is up, take one peach slice from each cup and place it on the first row of plates.   
6. Observe each peach slice for the first sign of browning and record the time this occurred.
7. At the same time, continue timing with the stopwatch. Repeat steps 5 and 6, but this time take the peaches out 10 and 15 minutes after the start of the experiment. Place the peaches on the second row and third row of plates respectively.

SIP Experiment Part 2

I decided to do an extension of the previous experiment to find out what is the least amount of time that the peaches have to be soaked in Vitamin C before they can retain their colour when placed outside. (this was taken from one of my previous posts) The reason why I wanted to do this experiment is because it is more practical: most people would not soak their peaches for that long before eating them. Soaking the peaches for so long would alter their taste as well. 


From the previous experiment: After soaking for 9 hours, lemon juice and lime juice were the clear winners.  I decided to test these juices for this new experiment. I also decided to test salt water (1 teaspoon) because it is the most cost-effective. 


In my next post I shall once again do a rough methodology for this extension experiment.

SIP Experiment Results

Continuing from the previous post, after 9 hours I took all the peach slices out and put them on the paper plates. I threw away the control and the peach in tap water because their it was obvious they were not effective.

After 9 hours of soaking

I ended up leaving the rest of the peaches overnight! I put a cover over them to prevent flies/lizards from interfering with the results of the experiment.

I woke up at 2.45 am to check on the peaches. (Actually no, I woke up to catch the rare total lunar eclipse and went to check on the peaches after that)

Here are the results after 6 hours of the peaches being taken out of the liquids in order of merit, starting from the least brown to the most brown:

Lemon Juice - Unchanged (Not brown at all)
Redoxon 1000
Lime Juice
Orange Juice (slight brown)
Redoxon 500 (totally brown)
Kiwi Juice (totally brown)

At 8.30 am the next morning, I recorded down their appearances again:

Lemon Juice (still the best)
Redoxon 1000
Lime Juice
Orange Juice (slight brown)
Salt water (1/2)
Salt water (1)
Redoxon 500
Kiwi Juice

8.30 am (about 12 hours after peaches were taken out)

The last 4 were completely brown. However, I had forgotten to note down the appearances of the 2 peaches placed in the salt water at 2.45 am! But judging from the rest of the peaches, things had not changed much 6 hours later.

SIP Experiment Trial 2

 The tentative methodology really helped! I was a lot more organised then, so the experiment was a success. Here are some of my observations:

1. Trial 1 actually helped in this experiment, because I was better at taking the peaches out of the cups and was able to record their appearances faster. This minimised the time the peaches were exposed to air.

2. The peaches in the juices appeared slightly discoloured, but this was because of the colour of the juice which stained the peaches.

3. Naturally, I took many pictures, but had to make sure my shadow (or the camera's) did not get in the way of the experiment. Later, I also had to make sure the lighting of the set-up was the same, or the peaches may look lighter or darker than they actually were during the experiment.

I also made some modifications to the methodology. Instead of observing them every 5 minutes, I observed them at 5 minute intervals for the half hour (6 times), then at 15 minute intervals for the next 1 hour (4 times), then at 30 minute intervals for the next 2 hours (4 times). I did this because I realised that in the 1st experiment, after around 30 minutes the rate of browning of the peaches slowed down. Thus, it would be all right to observe them at progressively longer intervals.

After 3 1/2 hours, the control was so brown it looked more like a potato wedge covered in dark gravy. The peach in tap water did not fair too well either, being only slightly less brown than the control. (of course I will use more precise terms in my report!) But all the peaches in the Vitamin C remained perfectly unchanged, since the start of the experiment! They were still a brilliant yellowish-white. This really surprised me, for I had not thought that Vitamin C could be such a wonderful preservative! I expected them to be slightly brown, but not as brown as the tap water or salt water.

I decided to leave the peaches in the cups to observe them after 5 1/2 hours and after 9 hours since the start of the experiment. At the 9 hour mark, I took the peaches out of the cups and left them on the plates, then observed them to see if they would turn brown after being exposed to air and having been soaked in their respective liquids for 9 hours. 1 hour after I did so there was no change in appearance in all the peaches!

This is very interesting. The peaches in Vitamin C had not changed their colour since the start of the experiment. After 9 hours of soaking, when taken out, they did not change their colour even after being exposed to air. Hmm...I wonder what is the least amount of time that the peaches have to be soaked in Vitamin C before they can retain their colour when placed outside? After all, most people would not soak their peaches for 9 hours before eating them!

~~~

Experimental materials: fruits + redoxon + salt



Experimental materials 2: fruit juices + juice extractor



Experimental set-up

Peaches taken out after 5 minutes

Peaches taken out after 30 minutes

After 1 hour

After 3 hours

SIP Tentative Methodology

Materials needed:

• 10 plastic transparent cups
• 10 small paper plates
• 9 plastic spoons
• Marker
• Juice extractor
• Knife
• Stopwatch 
• Measuring Cylinder

Liquids Tested:

• 100 ml Tap Water
• 100 ml Tap Water + 1 teaspoon of salt
• 100 ml Tap Water + 1/2 teaspoon of salt
• 2 Lemons
• 2 Oranges
• 3 Limes
• 2 Kiwis
• Redoxon (1 tablet)
• Redoxon (1/2 tablet)
• 1 peach

Method:

1. Label all plates and cups with a marker. Arrange everything on the table.

2. Squeeze the fruits using the juice extractor and pour the juice into the cups. 

3. Measure 100 ml of water from the measuring cylinder and pour into the respective cups (tap water, salt water and redoxon). Put the redoxon tablets in gently, making sure not to make the water in the cups spill out excessively.

4. Cut the peaches quickly, and once 10 peach slices are obtained, drop the peaches in carefully into the cups. Put one peach slice  on the control plate.

5. As soon as slices are put in, start timing with the stopwatch immediately.

6. Take the peaches out at 5 minute intervals and place them on the plates. Record their appearance, then quickly put them in the cups again.

7. Repeat step 6 for about one hour.