The Enzymatic Browning Of Apples

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The Enzymatic Browning of Apples
Practical experiment:
The purpose of the experiment is to measure the level of browning, due to the effects of the enzyme called polyphenol oxidase (phenolase), on apple slices exposed to different Ph. levels.
When exposed to oxygen the enzyme catalyzes the reaction creating melanins (brown pigments) on the fruit. Soaking the apple slices in acetic acid, orange juice (ascorbic acid), tap water and calcium carbonate (alkaline) will affect the rate in which the apple slices brown. The reduction of the browning is dependent on the Ph. levels of the soaking solutions, also soaking the apple slice in water will restrict the amount of oxygen that comes into contact with the apple thus temporarily inhibiting the effects of the phenolase.
Understanding the Prac:
By peeling or cutting fruit and vegetables the enzymes that are stored within the plant cells are released. When in the presence of oxygen the enzyme phenolase catalyzes the biochemical reaction of converting phenolic compounds into melanins. Enzymatic browning occurs optimally between a PH of 5.0 and 7.0.
Browning can also occur via the bruising or other injury to the plant tissue, exposing the enzyme to oxygen. Although enzymatic browning is not always a defect, for instance it is required in the process of making raisins, coffee, prunes and cocoa, it does however have significant effects on the fruits and vegetables that do not require browning such as apples. Enzymatic browning not only

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