Today, Xiaobian will share the knowledge of color-changing fruit with you, and will also analyze and answer the color-changing fruit teaching plan in small classes.

Can the apple be eaten after it has changed color?

Apples can be eaten when they change color. If an apple is eaten for a long time, the bitten surface will appear yellow, and the water content of that part of the pulp will also decrease, making it more "soft" and less brittle. Experts explained that this is actually the result of apple oxidation. Although the "appearance" is ugly and the taste is not particularly good, in fact, its nutrients have not been lost, and eating it will not cause harm.

If it is safe to eat after cutting for half an hour, and the pulp inside is not corroded and infected, you can wash it and continue eating, or you can cut off the yellow side before eating. Of course, if it is stored for a long time, more than an hour or even half a day, then don't eat it.

Precautions for eating apples:

Apple has high nutritional value and is rich in vitamins and acids. Eating apples should not be too fast. Chewing in the mouth for a long time can secrete more saliva and gastric juice, which is conducive to promoting the absorption and digestion of apple nutrients by the human body.

From the point of view of nutrition, it does not advocate' wolfing down'. For people with bad stomach, it is especially necessary to pay attention to the speed of eating apples. Eating too fast can easily lead to indigestion and discomfort.

People's Daily Online-Is it most beneficial to eat apples in the morning? Eating apples like this is fatal.

Why do apples, pears and other fruits change color after being cut?

After apples, pears and other fruits are cut, the pulp will change color quickly, because the trace enzymes containing polyphenol oxidase in fruits promote this process. The cut apple can be soaked in a contain filled with water to prevent that sliced apple from blacken after being exposed to oxygen for a long time. The same effect can be achieved by coating syrup and honey on sliced apples and covering the surface of sliced apples with sugar.

All of these forms an isolation film, which isolates the apple tissue from the air, and more importantly, inhibits the diffusion of oxygen in the apple cells. Prevent oxygen from contacting with PPO and iron contained in plant cells.

Some fruits and vegetables have their own "switches" to destroy themselves. The moment you cut it with a knife, the self-destruction of fruits and vegetables begins. Its touch and color began to change, and it became no longer crisp and neat, and its surface turned brown. This is actually the most basic phenomenon, called oxidation.

These fruits all contain iron. When the surface of the fruit is cut and exposed to oxygen, the iron-containing elements begin to oxidize and the color begins to change.

People's Daily Online-A few tips for peeling apples without discoloration: coating honey to isolate oxygen.

What fruit changes color when it is oxidized?

Basically cut or opened fruit, the pulp will change color when exposed to air. Apples and pears are obvious. Dark fruit watermelon will also oxidize and discolor, but it is not obvious.

Will mango change color if it is cut for a long time?

Slightly oxidized and black can be eaten.

Mango pulp contains polyphenol oxidase. Once its cell tissue is destroyed after peeling, the phenols in mango will be oxidized into brown quinones when it comes into contact with air, which will appear black on the pulp, but will not produce any toxic substances. Peel the blackened part and you can continue to eat it, but don't eat it if it is seriously blackened, which means that mango has been rotting and deteriorating for too long, and eating it is harmful to your health. Usually it is no problem to eat mangoes cut the day before the next day. Mango cutting time should not exceed 2 days.

Those fruits will change color when they are cut. Strawberries, bananas, pears, apples, mangoes, oranges and grapes.

Apples, pears and other fruits will soon change color after peeling, so you can eat them yourself. If it is used to entertain guests, it will not look good. Fruit discoloration is due to the action of enzymes. This situation can be changed if the freshly cut fruit is soaked in salt water.

What fruit will change color after peeling?

Pears, apples and bananas change color when they are cut.

The discoloration of fruit after cutting is called browning. Browning is a common discoloration phenomenon in food, especially when fresh fruits and vegetables are processed, stored or mechanically damaged, the original color of food becomes dark. These changes belong to Browning.

Proper browning is beneficial in some food processing processes, such as the production of soy sauce, coffee, black tea and beer, and the baking of bread and cakes. In other food processing, especially fruit and vegetable processing, browning is harmful, which not only affects the flavor, but also reduces the nutritional value. Therefore, it is of great practical significance to understand the reaction mechanism of food browning and find control methods.

Methods to prevent fruit from discoloring:

1, with lemon juice. Lemon juice can prevent oxidation because it contains an effective antioxidant-citric acid. You can mix cold water and lemon juice in a bowl to soak the fruit to prevent oxidation. A spoonful of lemon juice is added to a glass of water. You just need to soak the apple for 3 to 5 minutes, then pour out the water and rinse it clean.

Step 2 use salt. Salt is a natural preservative, which can effectively prevent fruit from oxidation. Using this method, half a teaspoon of salt can be dissolved in about 946 ml of cold water. Soak the cut fruit in salt water for 3 to 5 minutes. After that, take out the fruit and wash it thoroughly on a sieve or colander. Fruit slices should be kept for a period of time without oxidation.

Step 3 use carbonated drinks. Carbonated drinks containing citric acid are also very useful for preventing fruit oxidation. Lime juice and ginger ale are two popular antioxidant choices. Just put the fruit in a bowl filled with carbonated drinks of your choice, wait for 3 to 5 minutes, and then pour out the water.

Baidu encyclopedia-fruit preservation

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