How do apples not oxidize when stored

After cutting the apple, it can be soaked in salt water, coated with lemon juice, sealed and refrigerated, vacuum packaged, or treated with honey water to delay oxidation. The oxidation of apples is mainly caused by the contact between polyphenol oxidase and oxygen, and the color can be effectively maintained by physical isolation or acidic environment inhibition of enzyme activity.

1. Salt water immersion

Soak sliced apples in light salt water for 3 minutes, sodium ions can temporarily inhibit polyphenol oxidase activity. This method is easy to operate and does not affect the taste, but soaking for more than 5 minutes may lead to excessive sodium content. hypertensive patients should use it with caution. After processing, the apples should be stored at room temperature for about 2 hours without browning.

2. Lemon Juice Application

Fresh lemon juice is rich in vitamin C and citric acid, and directly applying it to the incision can form an antioxidant barrier. Mixing 5 milliliters of lemon juice with every 100 grams of apples yields the best results, and those with citrus allergies can use white vinegar as a substitute. This method can keep apples in their original color for more than 4 hours, but it will add sourness.

3. Sealed refrigeration

Wrap the incision tightly with cling film and refrigerate at 4 ℃. Low temperature environment can reduce enzyme activity, and isolating oxygen can slow down oxidation reaction. This method is suitable for situations that require long-term storage. The fully wrapped apple chunks can still maintain a good appearance after being refrigerated for 12 hours, but the taste will gradually become softer.

4. Vacuum packaging

uses a vacuum machine to extract the air inside the packaging, completely blocking the path of oxygen contact. Vacuum processed apple slices can maintain their color without browning for 48 hours under refrigeration conditions, making them suitable for bulk storage or outdoor carrying. Attention should be paid to the possibility of squeezing the fruit pulp during the vacuum process. It is recommended to first perform hardening treatment.

5. Honey water treatment

Honey contains natural antioxidant components, and soaking apple chunks in 10% honey water for 3 minutes can form a protective film. The synergistic effect of catalase and phenolic substances in honey can maintain non oxidation for 3 hours at room temperature. In patients with diabetes, oligosaccharides can be substituted, which is less effective but safer.

For daily storage of apples, it is recommended to prioritize physical isolation methods, such as cutting apples in sealed boxes and filling them with drinking water. Pour out the water before drinking. Whole apples should be placed in a cool and ventilated place, avoiding being placed with fruits that release high amounts of ethylene. Long term storage can be done by peeling and cutting into pieces, followed by quick freezing. When in use, it can be directly mashed or heated for cooking. The oxidation reaction is basically stagnant in the frozen state. Regardless of the method used, processed apples should be consumed within 24 hours to ensure their nutritional value and safety.