SILVER

Orange you glad you are not an apple; The Effect of Vitamin C on the Oxidation Process

I experimented on apples to measure the effectiveness of various antioxidant treatments.
Alyssa Kim
Grade 7

Hypothesis

If there is a higher dosage of vitamin C then the oxidation process in the apple slices will slow down because vitamin C can prevent oxidative stress which is a similar process to the oxidation in apples.

Research

Oxidation in apples is a chemical process. When the apple is cut, oxygen is introduced to the injured plant tissues. Once oxygen is present, the polyphenol oxidase enzymes in the chloroplasts rapidly oxidize phenolic compounds that are present in apple tissues to o-quinones. The O-quinces produce the brown color by reacting to form the compounds with amino acids or proteins. 

  • Apples have different levels of original enzyme amount so they will oxidize at different rates 
  • The level of original polyphenol and enzyme and differs by apple so for the experiment the same apple must be used. 
  • Vitamin c can also be called ascorbic acid, and it is a good source for food color preserver
  • Without Vitamin C there could be a development of scurvy, scurvy is caused if vitamin c is no longer in your body for 3 months because our own bodies can not create more.
  • Colour is one of the easiest ways to see if oxidation has worked. 
  • When the apple is cut they are exposed to oxygen and free radicals released from the apple.
  • When an apple undergoes the process this is when the apple undergoes the oxidation process eventually turning it brown. Enzymes in the apple oxidize phenolic compounds after oxygen goes into the injured plant tissue, tuning the apple tissues to form melanin.
  • This is a very simple way to look at oxidation because I do not have the proper equipment for bigger experiments. I had to try it on a smaller sample. Oxidation is also in human bodies, it causes many diseases such as cancer. 
  • Vitamin C prevents genetic mutation seen in this study https://www.jbc.org/content/277/19/16895.short
  • Vitamin c is also more frequent in smokers, low incomes, people with advanced cancer. With vitamin c deficiencies you have less chance of surviving it 
  • Critically ill patients have low plasma levels of vitamin c, 60mg is sufficient for most adults. 
  • Standard enteral provides 100-200mg of vitamin c to critically ill patients. It is insufficient to meet the needs of patients, and they need at least 2-3g of vitamin c respectively, which is insufficient to meet the needs of critically ill patients. 
  • 1g or more vitamin C can have consequences for many people, the consequences include diarrhea, nausea, vomiting, heartburn, abdominal cramps, headache, insomnia. 
  • Oxidation is a normal reaction in the body
  • Oxidative stress is when there is an imbalance between free radicals and antioxidants in the body, leading to diabetes atherosclerosis, hardening of blood vessels, inflammatory conditions, high blood pressure, heart disease, neurodegenerative diseases, and cancer.
  • The vitamin C in orange juice can degrade if stored in clear packaging which allows the sunlight to degrade it or contained in a polyethylene or polystyrene package which allows in oxygen also degrading the vitamin C
  • Other forms are lipid oxidation and oxidative stress
    • Lipid oxidation is between fatty acids and oxygen while oxidative stress is imbalaan nce between production and accumulation of oxygen reactive species.

Variables

Manipulated: Vitamin C amount

Responding: Oxidized amount in apples

Controlled: Apple Slices, Water amount, vitamin C tablet brand, room tempature

 

Procedure

  1. Cut an apple into approximately the equal size and the same weight
  2. Fill 6 cups each with 200 ml of pure water
  3. Put in one cup 200ml of orange juice
  4. In every 5 cups that have 200 ml of pure water put in 60mg, 120mg, 180mg, 240mg, and 300 mg of vitamin C each
  5. While waiting for the tablets to dissolve put in two cups each that have no liquid an apple slice each
  6. Put in the leftover cups each one apple slice, the orange juice, and water cup
  7. Label each cup with what liquid is containing it.
  8. Seal each cup except for one cup that has no liquid and only an apple slice. 
  9. Take observations at 24, 48, and 72hrs  

 

Observations

First Trial

24hrs

  • Apple in Orange Juice
    • 5 brown spots
    • Has white spots around the sides
    • Hard 
  • Non-sealed Apple
    • 9 brown spots
    • Dry and crusty
    • Shriveling
  • Sealed Apple
    • 5 cm of brown spots covered apple
    • Dry
    • 3cm long brown stripe
  • Apple in 60mg of Vitamin C
    • No brown spot
    • Mushy
  • Apple in 120mg of Vitamin C
    • No brown spots or lines
    • No color change
  • Apple in 180mg of Vitamin C
    • No brown parts
    • Slight pink hue
  • Apple in 240mg of Vitamin C
    • No brown spots 
    • Pink hue is evident
  • Apple in 300mg of Vitamin C
    • Pink Hue is most evident
    • No browning
  • Apple in water
    • Mushy
    • Brown splotches that cover 13 cm of the apples
    •  

48hrs

  • Apple in Orange Juice
    • 8cm brown spots
    • More strong then water filled apples
  • Sealed Apple
    • 20cm brown long streaks
    • 5cm new brown spots
    • Shriveling
    • Crust had formed and is dry
  • Non-sealed Apple
    • 54 brown coverage
    • Dry and crusty
    • Shriveling
  • Water Apple
    • 5cm brown spots
    • 9 cm brown splotch
    • White translucent edge
  • Apple in 60mg in Vitamin C
    • Pink hue 
    • 18 cm browning coverage of apple
  • Apple 120mg of Vitamin C
    • 12cm browned coverage
    • Pink hue
  • Apple in 180mg of Vitamin C
    • Pink hue
    • 4cm browned coverage
  • Apple in 240mg of Vitamin C
    • 2 cm browned coverage
    • Mushy
    • Pink hue
    • White translucent edge
  • Apple in 300mg of Vitamin C
    • No browning 
    • Mushy
    • Pink hue

72hrs

  •  Apple in Orange Juice
    • Brown spots that are 1 cm each
    • Parts of Apple are falling apart
  • Non-sealed Apple
    • 100 cm of brown spot coverage
    • 100% coverage of browning
    • Size has decreased
    • Signs of rotting
    • Dry and crusty
  • Sealed Apple
    • 120cm brown spot coverage
    • 100% brown spot coverage
    • Dry and crusty
    • A slight smaller size compared o start
  • Water apple
    • 120cm new brown spot coverage
    • Mushy
  • Apple in 60mg of Vitamin C
    • 8 more 1 cm brown spots
  • Apple in 120mg of Vitamin C
    • 2cm brown streaks
    • 2cm brown spot
  • Apple in 180kmg of Vitamin C
    • 3 cm brown streak
  • Apple in 240mg of Vitamin C
    • 2cm brown spot
  • Apple in 300mg of Vitamin C
    • No brown spots
  • Every trial and control sample had molding occuring

 

Second Trial

24hrs

  • Apple
    • 2cm brown spot
    • A total of 2cm brown streaks
    • 3cm coverage of brown splotches
    • Slight crust

 

  • Sealed Apple 
    • 7 brown spots that cover a total of 1cm
    • 5cm coverage of brown splotches
    • Dry and a crust

 

  • Water apple 
    • Rotting edge 
    • Total of 7cm brown splotch
    • 2cm brown streaks in total
    • 1cm brown spot
    • Mushy 

 

  • 60mg of VC
    • White rotting edge
    • Mushy
    • No color change

 

  • 120mg of VC
    • White translucent edge (sign of rotting)
    • Light pink hue but not evident

 

  • 180pmg of VC
    • White translucent edge
    • No color change
    • Pink hue can also be seen on the surface

 

  • 240mg of VC
    • White translucent edge
    • Pink hue covers all areas
    • Color turns slightly orange from the pink hue and original color of apple clashing 

 

  • 300mg of VC
    • White translucent edge
    • Pink hue
    • All surface have turned a shade of orange which is  not a sign of oxidation

 

  • Orange juice 
    • No rotting edge
    • 2cm brown splotch
    • Brown streaks that add up to 3cm
    • A total of 2cm of brown spots.

48hrs

  • Apple
    • 15cm total of brown splotches
    • A total of 5cm of brown streaks
    • 5cm brown spot total coverage

 

  • Seaed apple
    • 6cm brown spot total coverage
    • A total of 7cm for brown splotch coverage
    • 2cm brown streaks in total

 

  • Water apple
    • White translucent edge
    • 11cm brown splotches in total
    • A total of 4brown spots
    •  4cm brown streaks

 

  • 60mg VC
    • White translucent edge
    • Slight pink hue which seems to be only under the surface
    • 9cm brown splotches in total
    • A total of 3cm of brown spots

 

  • 120mg VC
    • White translucent edge 
    • Pink hue
    • 4cm brown splotches in total
    • 2cm total of brown spots
    • 3cm brown streaks in total 

 

  • 180mg VC
    • Pink hue
    • White translucent edge
    • 2cm brown spot

 

  • Vitamin C 240mg 
    • No signs of oxidation
    • No difference spotted from 24hour observations

 

  • Vitamin C 300mg
    • No signs of oxidation
    • No differences
    •  
  • Orange juice
    • 4cm brown splotches
    • 2cm brown streaks
    • Rotting marks are seen

72hrs

  • Apple
    • Shriveled up 
    • 100% oxidized/90cm 
  • Sealed
    • 100%oxidized/110cm 
    • Crusty and dry
  • Water:
    • Different stages of browning were seen in different areas 
    • 100% oxidized/110cm 
    • No a lot of rotting seen 
    • Water turned yellow but were 
  • 60mg VC:
    • 4cm brown splotch 
    • 1cm spot
    • Little spots and specks of rotting
    • White translucent edge 
    • Pink hue
  • 120mg VC
    • White hues showing around the apple
    • 4cm brown spots 
    • 2cm brown streaks
    • 3cm brown patches
    • Pink hue
  • 180mg VC
    • 3cm brown splotches
    • 1cm brown spots
    • White splotches
    • Pink hue
  • 240mg VC
    • 1cm brown spots
    • White splotches
    • No other appranct changes
    • Pink hue
  • 300mg VC
    • No oxidation seen
    • Pink hue
    • White splotches around the apple slices
  • Orange Juice 
    • 2cm brown splotches
    • 2cm brown spots
    • Multiple rotting spots seen on one side

Analysis

 

For my first experiment there were sharp increases of oxidation between 48hours and 72 hours, the highest increase was seen in three trials that became oxidized 100%. A trend was spotted between the vitamin C water as every trial had no signs of oxidation in the first 24 hours. An outlier spotted was in the orange juice which did not follow this trend even when it contained vitamin c like the rest which could show that orange juice is not an adequate source for vitamin C. There was only a 5mg difference of vitamin C amount between the 60mg of vitamin C tablet. This revealed that orange juice was not a viable source of antioxidants as it had been advertised on the bottle. The trend revealed that the minimum amount of 60mg of vitamin C still had a positive effect on oxidation but any amount underneath it would not be beneficial. Whie an error could have been the rotting could have been mistaken as rotting or the other way around but those parts were peeled and the surface underneath was counted as browning if there were the signs. For my second experiment I saw the same observation that there was a sharp increase of oxidation between 48hours and 72 hours. The highest increases were once again seen in the non-sealed , sealed, and water apple that at my final observation became oxidized a 100%. The trends spotted in my second experiment were between the vitamin C water in which every trial in the first 24 hours had no signs of oxidation but an outlier was spotted amongst this trend. The outlier was in the orange juice which contained 55mg of vitamin C but had 7cm of oxidation seen in the first 24hours. Which was repeated once again from my first experiment when the orange juice had 5cm of oxidation seen. This repeating shows that orange juice is not an adequate source of vitamin C as it has been advertised as. While this trend also reveals the minimum amount of 60mg of vitamin C is effective as health officials are informing individuals of orange juice is not effective as advertised my manufacturing companies. An error in my second experiment would have been that there was a temperature difference from the first experiment and the second one and the ortting that was spotted. The outside temperature at the first experiment was around -15 celsius but at the time of the second one it was -30 celsius so this could have altered the results but it could have helped the rotting because not many signs of rotting were seen. While there wasn’t much rotting spotted I compared the areas to other apples and examined whether it was a sign of oxidation or rotting which was still not as precise. The rotting was at a minimum rate  there was less confusion when measuring and determining which parts of my apple were oxidized. Overall this experiment has very similar results except for the slight differences between the oxidized amount. While in the first experiment the highest oxidation was seen in the non-sealed apple because it did not shrivel up opposed to my second experiment where it did shrivel up so less oxidation was measured. The orange juice also had higher oxidation seen in the first 24hrs in the second experiment than my first, but in the end the first experiment nearly had 2times the second experiment’s oxidized amount. THis was a big difference so this could have been a result of the temperature difference or there could have been a slightly higher amount of vitamin C then calculated from the bottle.  There were slight differences from the amount oxidized between trials compared between both of my experiments but other than the other changes stated above they held similar results. The vitamin C worked to an extent and even while the orange juice was not as effective compared to the tablets they had a better effect overall compared to the control sample which was oxidized to a 100% at 72 hours which was seen in both experiments. The vitamin C tablets worked better than the orange juice but if vitamin C tablets are not avaible drinking orange jucie would be good alternative if dirnking it over 55 mg. Seen in the comparision of graphs it was seen that for the first one the apple, sealed, and water was going down in amounts but for the second one apple, sealed, and water went up in the amount observed. Though there didn't seem to be many different changes an did not seem to have a whole wide effect on my results. 

Conclusion

In conclusion my hypothesis was true for both of my experiments because as there was a higher concentration of vitamin C had a slower oxidation rate seen when the 300mg of vitamin C prevented any signs of oxidation from occurring, even the lowest amount of vitamin C in the orange juice which showed an outlier still only had 33cm of oxidation seen in total. The control sample also showed the differences between vitamin C located apples because the control sample eventually became oxidized 100% while the vitamin C prevented most of the oxidation process. My second experiment held a similar result because as the amount of vitamin C concentration decreased more oxidation was spotted. This was seen when 300mg of vitamin C showed no signs of oxidation and remained similar to the start of the experiment and the lowest amount of vitamin C 55mg which was in the orange juice showed signs of oxidation in the first 24 hours. This also revealed how ascorbic acid is helpful as a food colour preserver and perserve the colour for long periods of time if used in high concentrations. This shows that antioxidants can prevent oxidation in many different forms and still be very effective against the different types such as the oxidation in apples, or in the human boyd, oxidative stress. With both experiments backing up my hypothesis it can be observed that vitamin C becomes more effective in higher dosages and will have a drastically different results compared to not having any vitamin C. VitaminC  can be seen as an effective source of antioxidants and this information can help prevent others from getting medical conditions that have oxidation in the process.

Application

To extend on this experiment I could turn it into a research project and research the different forms of oxidation and the effects and cures for the forms. This could include lipid oxidation and oxidative stress in which both cases antioxidants can be used to counter or slow down the progress. The study of these areas would help spread knowledge about the importance of antioxidants which would help people from getting lipid oxidation or oxidative stress or the most basic prevent their apples in their lunch from being all brown. I could also research if  orange juice is as effective as an antioxidant as the marketing reveals it to be. Based on my experiment it was seen that vitamin C could not prevent the first 24hours of the oxidation process so orange juice is as effective and filled with vitamin C as it is advertised with. My experiment can not only help prevent apples from being brown but help prevent certain medical conditions.

Sources Of Error

Sources of error in my first experiment could have been the signs of oxidation being mistaken as sign of rotting of the signs of rotting being mistaken as oxidation. This would have casued miscalculations which would lead to the amount of oxidation being false. I attempted to solve this by comparing the signs to other apples or peeling back the spots to identify what was underneath. For my second experiment the source of error could have been the tempature difference from the first experiment, because they were drastically different this could have lead to the signs of oxidation and rotting being drastically different, and would lead to differing results. The second error could have been repeated from the first of the oxidation either identitfied as rotting or the other way around. I attempted to solve this error in the same way as the first. 

Citations

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  • Vitamins at physiological levels cause oxidation to the DNA nucleoside deoxyguanosine and to DNA—alone or in synergism with metals. (2012, March 30). Retrieved from https://academic.oup.com/mutage/article/27/4/511/1118664
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Acknowledgement

Thank you to my teacher Mr.Hotzel and Ms. Davis, our school science fair coordinator for helping my school fair project.