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!

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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.

SIP Trial Improvement and Insights

So things to work and improve on:

• Be more prepared! I should have thought through the experiment a bit more carefully. I think writing out a rough methodology and the list of materials needed would be useful so that my thoughts are more organised. 

And to solve the earlier problems:

1.  Label everything beforehand with a marker.
2. Cut the peaches as fast as possible so that they will not brown so quickly.
3. I think using spoons instead of chopsticks would work better to take the peaches out to prevent them from disintegrating. 
4. To solve the problem of putting them in all at once, I will rope in the help of my family members.

I hope the next experiment will work better!

SIP Experiment Trial 1

I decided to go ahead with my experiment yesterday! After buying the necessary materials, I was all ready to start. All I can say is that I only wish I had done more thinking before starting because the experiment was a total failure!

- The first thing I did was to get 10 transparent plastic cups and 10 small paper plates to put the peach slices and different liquids in. I decided to use two fruits for each type of fruit because I highly suspected the tiny lime may not contain enough juice to submerge the peach slice. But I overlooked one problem: the fact that at first slice of the knife, some juice squirted out. This was an especially big problem for the limes because every drop of juice could not be wasted. Thus in the end, I used 3 limes to make up for the wastage.

- I then laid everything out nicely onto the table before getting ready to cut the peaches. However, as soon as I had cut the peaches and was all ready to put the peaches into the cups, I realised I had forgotten to label all the cups and plates! Frantically, I began labeling them, but by the time I had finished the peaches were already turning brown!

- I decided to just continue with the experiment to see if I would encounter any more problems, even though I knew I would have to conduct the experiment again because the peaches were brown. So I took the peaches out at regular 5 minute intervals and placed them on the plates to see how brown the peaches were. (see pictures below)

There were a few problems with this:

1. I used chopsticks to take the peaches out, but the peaches were quite slippery and every time I took them out they seemed to disintegrate a little.

2. It was difficult to take them out all at once once the 5 minute interval was reached. The same problem was encountered at the starting to place all the peaches into the cups at the same time.

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Peaches in cups

Peaches taken out after 5 minutes



Peaches taken out after 10 minutes

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 So I encountered quite a number of problems in this try. In my next post I shall state what I should improve on to make the experiment more successful :)

SIP Materials + Research

After doing much research, I decided to test a few commonly available household products to see which of these can prevent the browning of the peaches the best. The products I tested are:

1. Tap Water
2. Salt Water (1 teaspoon of salt)
3. Salt Water (1/2 teaspoon of salt, to see if the concentration of salt affects the amount of browning of the peaches)
4. Lemon Juice
5. Orange Juice
6. Lime Juice
7. Kiwi Juice
8. Redoxon (1 tablet)
9. Redoxon (1/2 tablet)

And of course, a control which was exposed to air so that a fair comparison could be made.

I do think that the concentration of Vitamin C in products 4 - 9 affects how well they can prevent browning, so I did more research to find out the concentration of Vitamin C in each of the products. Here is the list (per fruit) :

1. Lemon (46 mg)
2. Orange (53 mg)
3. Lime (29 mg)
4. Kiwi (98 mg)
5. Redoxon tablet (1000 mg)
6. Redoxon 1/2 tablet (500 mg)

* Vitamin C content figures given are approximate, may vary between different varieties of the same fruit or even between separate fruits of the same variety. The ones listed here are taken from http://www.naturalhub.com/natural_food_guide_fruit_vitamin_c.htm