After the apple juice is squeezed, it is boiled in a pot, how can it be eaten black?

The starch oxidizes and turns black, which does not affect eating.

The apple juice is black and cannot be drunk as soon as it is squeezed, and the reason why it turns black is because of oxidation, and continuing to drink this apple juice may cause physical discomfort. If you want to avoid the apple juice from turning black due to oxidation, you can first pour some salt into the cup or drop a few drops of lemon juice to inhibit the oxidation rate of apple juice.

The reason why the apple juice turns black as soon as it is squeezed is mainly due to the oxidation reaction with the air, and continuing to drink this juice may cause gastrointestinal discomfort.

If you want to avoid the blackening of apple juice after it is squeezed, you can put a little salt water in the cup containing the apple juice and pour the juice into the cup with salt water to avoid rapid oxidation of the juice.

In addition, you can also drop a few drops of lemon juice into the cup, and then pour the apple juice into the cup, which can also slow down the rate of blackening of apple juice, because lemons contain a lot of vitamin C, which has strong antioxidant properties.

Freshly squeezed juice is very easy to brown, brown does not mean that it is toxic and harmful, it can still be sold and drunk, but it just means that the polyphenol health ingredients in fruits and vegetables are oxidized in contact with oxygen, and the antioxidant effect will be violently reduced.

Freshly squeezed apple juice is a freshly squeezed juice, the main ingredients are fresh apples, fresh pure water, freshly squeezed apple juice is nutritious, suitable for all ages, and is tolerant and insoluble cellulose. When making this juice, add some salt water or lemon juice to the loin to prevent oxidation.

Freshly squeezed apple juice is prone to blackening due to the oxidation of apples with the air. Once an apple is cut, it produces the same reaction when exposed to air.

The blackening of apple juice (which is actually yellowish-brown) is due to the oxidation of Fe2+ to Fe3+, and the addition of vitamin C to this apple juice can avoid this phenomenon, indicating that vitamin C can reduce Fe3+ to Fe2+, and vitamin C is reductive.

How do you avoid apple juice from going black?

Put some salt water in the cup where you want to hold the juice, as long as the salt water has a little salty taste, and then pour the juice into the cup with salt water, and the juice will not be dark.

Lemons are rich in vitamin C, so adding a few drops of lemon juice to apple juice can also slow down the rate at which the juice turns black.

The discoloration reaction occurs mainly due to the presence of phenolic compounds in these plants. For example: polyphenols, catechols, etc.

Phenolic compounds are easily oxidized to quinones, that is, they change color and turn yellow, and the color gradually deepens with the increase of the amount of reaction, and finally turns dark brown. The oxidation reaction occurs due to the contact with oxygen in the air and the release of phenol oxidase in the cell.

Phenolic oxidase exists in organelles and cannot come into contact with phenolic compounds until the tissue is damaged, and oxygen in the air cannot enter, so no oxidative discoloration reaction occurs. When the cell tissue is damaged, phenol oxidase is released to contact with phenolic compounds, catalyzing the oxidation of phenolic compounds, coupled with the action of oxygen in the air, a discoloration reaction will occur. Among them, polyphenols can be directly oxidized to quinones and change color.

Catechol molecules, on the other hand, polymerize under the action of phenol oxidase. Two catechol molecules are linked together to form catechol dimers, which in turn can be joined in pairs to form tetramers. The individual catechol molecules and their dimers and tetramers are all colorless, but catechol tetramers can form multimers, which are purple.

So the more polymers are formed, the darker the color of the apple juice will be.

When apples change color, the amount of vitamin C will decrease, affecting the nutritional value. To prevent the apple from changing color after cutting, the best way to keep it out of contact with the air is to put a little salt water in the apple juice.

Simple, you soak the fruit in salted water when you peel it. Then add a small amount of salt when juicing. It's sweet and doesn't change color. A small amount, a little bit.

Wrap it in plastic wrap and try it if you don't believe it.

The discoloration is due to the oxidation of the ferrogen in it from divalent to trivalent, and this problem will not occur with a tablet of vitamin C. Because VC is a strong reducing agent, it will not cause harm to the human body if taken in moderation, and it is really unnecessary if you drink it yourself, because the discoloration is not much related to the nutrients.

Apple oxidation is mainly due to the oxidation of VC under the action of enzymes.

Solution: 1 is to isolate oxygen (did you do it?) Waiver).

2 is to kill enzymes, that is, to cook a little, as for how much time and how much temperature you have to try yourself. For your reference, 70 degrees for 30 seconds.

3 Add a little salt to the li! Give it a try! Really, it doesn't affect apple juice nutrition.

You can add some salt water, or lemonade.

When apples are peeled, the phenols in plant cells are oxidized with the air under the action of phenols, producing a large amount of quinones. The new quinones can cause plant cells to turn brown rapidly, a change called enzymatic browning of food. So apples will change color after peeling and leaving them for a while.

This is also the case for apples and pears, as well as some vegetables (such as potatoes and eggplants). This browning affects the appearance of the food, reducing the nutrient content of the outer layer, but it is still edible. If the apple is left for a long time after peeling, the oxidative decomposition of plant cells in the air is intensified, the nutrients in the outer layer of the apple are decomposed more, and the pectin substances are further decomposed into pectin acid and methanol under the action of enzymes, making the flesh loose, moist, discolored, tasteless, and even rotten and deteriorated.

The best way to do this is to rub the skin with salt before peeling, then wash it off, and then peel the apples, so that the apples will not oxidize, and they will last longer than soaking them in salt water after peeling, and they will not have a salty taste.

At the beginning, I talked about iron, and then I copied a paragraph, which talked about polyphenolic compounds. The top and bottom are not in the same context. Do polyphenols have a dime to do with iron?

Apples are rich in phenolic compounds that are highly susceptible to oxidation. After cutting, the phenolic compounds are oxidized by the air, turning yellow in color and gradually turning black, but it does not affect health.

Homemade fruit juice should be drunk immediately after preparation, otherwise the vitamin components are exposed to the air for too long and are prone to oxidation, and the taste will also deteriorate.

Don't drink juices with high acidity on an empty stomach, eat some staple foods before drinking them to avoid stomach upset. Whether it's fresh fruit juice, pure fruit juice or fruit drink, try to drink as little as possible during lunch and dinner.

The acidity of the juice will directly affect the acidity of the gastrointestinal tract, a large amount of fruit juice will dilute the concentration of gastric digestive juices, and the fruit acids in the juice will also combine with some nutrients in the diet to affect the digestion and absorption of these nutrients, so that people feel full of stomach when eating, unable to eat, poor digestion after meals, and stomach discomfort.

How can there be so much nonsense above, if you beat apple juice, you put some salt or salt water and beat it together, and it won't be dark.