To keep apple juice from oxidizing, you can add some brine or lemon juice when making this juice, or you can dip cut apples in water or coat the cut surface of the apples with syrup or honey.

There are two ways to stop apples from discoloring: one is to remove enzymes and the other is to remove oxygen. By dipping cut apples in a container filled with water before serving, the cut surface of the apple is prevented from being exposed to oxygen for an extended period of time.

Covering the cut surface of apples with syrup, honey, and covering the cut surface surface of apples with granulated sugar have the same effect. These create a barrier film that separates the apple tissue from the air and, more importantly, inhibits the diffusion of oxygen into the apple cells. By preventing oxygen from coming into contact with PPO, the iron element contained in plant cells.

Enzymes are essential to living organisms and are more sensitive than other substances. In order to eliminate enzymes, or at least slow down the rate of change, a slight adjustment of the environment is all that is needed. When lemon juice is drizzled on an apple, the pH of the environment changes, and the PPO is less active than it would be without the lemon juice.

And lemon juice has other effects lemon itself absorbs oxygen, which prevents it from reaching the apple's tissues and acts as an antioxidant.

Extended information

Nutritional composition of apple juice

1, carbohydrates

Carbohydrates are one of the main components of apple juice, accounting for more than 95% of the total soluble solids. Fructose and glucose are the two main carbohydrates in apple (juice), with contents of 3.2%-10.5% and 0.17%-4.1%, respectively, and the ratio of fructose and glucose content is greater than 2.

In addition to these two monosaccharides, apple juice also contains considerable sucrose as well as sorbitol (polyols), with contents of 0.2%-5.6% and 0.16%-1.2%8, respectively. -1.2%8.

2. Phenolic compounds

Phenolic compounds affect the color, texture, flavor and metabolism of foods of plant origin, and are recognized as beneficial to human health.

Phenolic compounds in apples can be divided into six categories: flavonol glycosides (flavonoids, quercetin and quercetin conjugates), anthocyanins, dihydrochalcone (rhizoderma and rhizoderma glycosides), catechins and epigallocatechins, phenolic acids (malic acid and chlorogenic acid) and proanthocyanidins.

3, dietary fiber

In addition to being rich in polyphenols, apples and their by-products are also an important source of dietary fiber. Apples contain about 1.2% of dietary fiber. Dietary fiber includes soluble dietary fiber and insoluble dietary fiber. Studies have shown that consuming fruits and vegetables rich in dietary fiber can promote human health and reduce the risk of chronic diseases. Increased intake of dietary fiber can effectively reduce postprandial blood sugar levels.

Baidu Encyclopedia - Freshly Squeezed Apple Juice

Baidu Encyclopedia - Apple Juice

People's Daily Online - Uncover a few tips for cutting apples without discoloration: apply honey to isolate oxygen