Oxidation By Ace Ang, 5 Victorious, Rosyth School, 2010. Aim of Experiment The aim of my experiment is to find out if there are any other liquids to prevent oxidation of fruit better than those with Citric acid. How this piece of information can help mankind In restaurants, before chefs serve fruits, the fruits might get oxidized and spoil. Even if it doesn’t spoil it will not look presentable. Antioxidants will slow down the rate of oxidation. Many people apply Lemon Juice (Citric Acid) to reduce the rate of oxidation. I want to find out if there is an antioxidant that reduces the rate of oxidation further.
What is Oxidation? Oxidation is the interaction between oxygen molecules and the different substances they may come into contact with. Oxidation is the loss of at least one electron when two or more substances interact. Those substances may or may not include oxygen. Oxidation can be observed all around us. Rusting is a form of oxidation. You may notice a piece of fresh fruit turning brown – That is also oxidation.
Carrying out the experiment Steps Dip the pieces of apples into their respective liquids/Apply the piece of apples’ respective liquids. When done, place the pieces of apples on the piece of cloth Start timer for 1 hour. Take video of all the pieces of apples (Start of experiment, 0 Hour) At every 1 hour interval, take video of all the pieces of apple and record how brown they are. After 5 hours, take down the colour and video the pieces of apples as usual and stop the experiment. Make a table that shows what I observed during the experiment. Experiment 4 pieces of apples (1 Apple) 3 containers Lemon Juice, Milk, Green Tea A piece of cloth Timer Others There is an extra piece of apple. The apple will be used without any liquids applied to it.
Conclusion (Part 2) – Why? Why is the apple without anything applied to it the brownest? Basically, it has nothing, absolutely nothing that’s on it. So the oxygen in the air can interact with the substances in the apple easily. Why is milk 3rd? Milk basically has no antioxidant properties. Why is Green Tea 2nd? Green Tea has Polyphenolic Antioxidants. Why is Lemon Juice 1st? Lemon Juice has Citric Acid (Vitamin C). Lemon has a very high concentration of Citric Acid (Therefore many people use it to keep fruits fresh).
References http://www.wisegeek.com/what-is-oxidation.htm http://en.wikipedia.org/wiki/Antioxidant http://en.wikipedia.org/wiki/Citric_acid