Why do apples,turns brown when cut and left exposed to air? I need to know for a biology project thats due in tomorrow! Why do apple slices turn brown after being cut? It is connected with an enzyme where one of the colourless ingredients are air oxidised to a brownish oxidised product. The skin of the apple protects it from this process. The trigger for this is damage to the cells, such as when you cut the apple, which then results in certain enzymes within the cells being exposed to oxygen. The insides of apples turn brown when exposed to air thanks to a built in defense mechanism against bacteria and fungus. Biology I know there are questions here about apples turning brown specifically, but other fruits turn brown as well when cut open and exposed to air, like bananas and avocados... but oranges, watermelons, and strawberries (to name a few) won't turn brown from exposure to air. When you peel an apple or dice it, the surface of the cut fruit comes into contact with air. Keeping sliced, cubed or mashed apples looking fresh requires a strong acid to stop the chemical reaction that happens when the sweet, crisp inner flesh is exposed to the air. If you slice an apple and pack it for lunch you’ll find apple slices that have turned a light shade of brown when you open your lunch bag. One final fact about avocados that I feel compelled to include here doesn’t actually have anything to do with chemistry, but with the fruit’s name. This is great for preparing apple slices before you’re ready to eat them – for example, when preparing a snack for kids. Answer (1 of 3): Apples contain some phenolic compounds containing iron. Kitchen Science Why Do Apples Turn Brown? Ideal for salads and other recipes that call for sliced or diced raw apples, these non-GMO slow-browning apple varieties include Cortland, Cameo, SnowSweet, Gala, Goldrush, Ginger Gold, and more. Favourite answer. And you’ll even know how to stop it from browning. The chemical reaction causes an apple, and other fruits and vegetables to turn brown because of Enzymes that are the proteins which react with its environment, changing the color of an apple or other to brown. The brown phenols form a layer on the exposed surface and that is how apples turn brown. ‎In this episode, you’re going to learn why the insides of apples turn brown when exposed to air and what this has to do with why most human’s skin browns when exposed to the Sun. In this edition, we are going to find out the science behind this color transition phenomenon called as enzymatic browning. Answer Save. In this apple oxidation experiment, we are going to explore the chemical reaction that turns the apple brown. Why Are Ambrosia Apples so Slow to Brown? Oxygen oxidizes these phenolic compounds and turns them brown. 3 4 5. The enzyme responsible for this is polyphenol oxidase. Air has oxygen in it. 0 0. Lemon juice is rich in vitamin C, which is a natural antioxidant, and stops the oxidation process that turns apples brown when exposed to air. 1 decade ago. The purpose of this chemistry laboratory exercise is to observe the effects of acids and bases on the rate of browning of apples when they are cut and the enzymes inside them are exposed to oxygen. As I am writing this, I am indeed staring at some pathetic apple slices next to my laptop. Answer. Apples turn brown when exposed to air because of the oxidation process that goes on when the inside of the apple gets exposed to the ambient air which contains oxygen and water molecules. Apple contain an enzyme called polyphenol oxidase (PPO) also known as tyrosinase. The Aztecs named the trees it grew on ‘āhuacacuahuitl’. Apples and other fruit turn brown once the cut surface is exposed to air due to a reaction with oxygen in the surrounding air, a chemical reaction called oxidation. 1 decade ago. [TRANSCRIPT] Don’t miss future episodes of this podcast, subscribe here: iTunes | RSS/XML You can also find more episodes… So there you have it! Fresh cut apples turn brown when iron-containing chemicals inside apple cells react with oxygen in the air. The reason why apples and other fruits and vegetables turn brown is because they contain iron in them. Why do apples turn brown? why do apples turn brown when exposed to air and how long does it takes for it to turn brown? The reaction happens quickly, and so a sliced apple can start to turn brown in only a few minutes. Why Do Apples Brown? Relevance. Relevance. The skin of the apple protects it from this process. why do apples turn brown when exposed to air? Next time you slice up an apple, you’ll understand why it turns brown. Wiki User Answered . Have you ever wondered why apple slices turn brown when exposed to air? Why do apples turn brown when the are left in the air? These cells also contain different types of enzymes. 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