Write an essay on why apples change color, the mystery of apple discoloration essay

Yesterday, my aunt and brother were coming, and my mother bought a big bag of apples.

After eating, my mother peeled apples for everyone to eat, and my brother and I kept playing on the computer and didn't care about eating. After a while, the bright and white flesh of the apple turned a light brown color, and after a while, it turned a dark brown. What is the reason for this? ”

Today, I found the Juvenile Encyclopedia, and in it, I found the answer. This is because of the presence of phenols in apples as a result of maintaining their respiration. When the apple is peeled, the phenolic substances in the plant cells will be oxidized with the air under the action of phenolsase to produce a large number of quinones, and the new quinones can make the plant cells quickly turn brown.

Mainly used in the knife when peeling apples, the tannin in the apple flesh has a chemical reaction with the iron of the blade, and a black iron tannin is produced to cover the surface of the apple flesh. When the apple loses its skin, the pulp encounters air, and the organic matter in the pulp is oxidized and discolored by oxidase. So peeled apples will change color.

But you don't have to worry, although the color of the peeled apple has changed, as long as it is not left for too long, such an apple will not affect your health after eating. One thing to pay special attention to: the tannic acid in apples is difficult to dissolve in water, so don't wipe them with a handkerchief or towel after eating apples, you know?

In addition, let me tell you a trick: drop some lemon juice on the cut surface of the apple, not only does not change color, but also retains the original flavor, and some fruits that are easy to change color can also be treated in this way, the effect is excellent.

It is true that there is science everywhere in life, and only when we continue to learn and explore science will society continue to progress! By peeling apples that change color, I not only learned a little bit about it, but more importantly, I realized how wonderful nature is!

The specific process cannot be repeated, please check the relevant popular science books.

The specific process cannot be repeated.

One day, my family served a guest with peeled apples. The guests didn't eat it, and the color of the peeled apple turned brown. After sending off the guests, I asked my father:

Why do apples change color? Can you still eat it after changing color? Dad smiled and said

Let's do a little experiment! He brought a few bowls and an apple. He peeled the apple and cut it into three pieces, and told me to put the first one in an empty bowl of land objects; the second piece is placed in the second bowl, but with a glass clasped on; The third piece was placed in a third bowl, and some salted water was poured over the apples.

Then he said mysteriously: "Don't rush, you will understand in a while." ”

I lay on the edge of the table, my eyes fixed on the apples in the three bowls ......Thirty minutes passed, and I saw a strange phenomenon: the apple in the first bowl turned brown, the apple in the second bowl changed color slightly, and the apple in the third bowl was as fresh as ever, and did not change color at all. Dad gave me a taste, I took a bite, wow!

It's so sweet! I can't wait to ask what's going on? Dad patted me on the head and said, "Apples contain an ingredient called enzymes, which chemically react with oxygen in the air and become oxidases, which make apples brown."

My dad and I worked together to learn the secret of apple discoloration, and I was so happy!