How to prevent oxidation of apples

Apples can be prevented from oxidation by soaking them in salt water, applying lemon juice, wrapping them with plastic wrap, storing them in cold storage, vacuum sealing, and other methods. The oxidation of apples is mainly due to the enzymatic browning reaction caused by the contact between polyphenol oxidase and oxygen.

1. Soaking in Salt Water

Soak the cut apples in light salt water for a few minutes. Salt can inhibit the activity of polyphenol oxidase and slow down the oxidation rate. The concentration of saltwater should not exceed 3%. After soaking, rinse with clean water to avoid excessive saltiness. This method is suitable for short-term preservation, such as making fruit salads or serving bento meals.

2. Applying lemon juice

The vitamin C and acidic environment in lemon juice can effectively block oxidative reactions. You can directly drop a few drops of lemon juice on the cut surface of the apple, or mix lemon juice with water in a 1:1 ratio and spray it. This method not only prevents oxidation but also adds fruity aroma, making it suitable for direct consumption scenarios.

3. Wrap the sliced apple tightly with cling film, which can physically isolate oxygen contact. Be sure to ensure that the cut surface fully adheres to the cling film without leaving any gaps. This method is suitable for short-term storage in household refrigerators, but it is recommended to consume within a few hours to avoid changes in taste caused by prolonged storage.

4. Cold storage

Low temperature can significantly reduce the activity of polyphenol oxidase. After cutting apples and storing them in a sealed container, refrigeration can delay oxidation for several hours. The best temperature control is around four degrees Celsius, but the taste of the apples after refrigeration will be slightly harder, making them suitable for subsequent cooking or making salads.

5. Vacuum sealing

uses vacuum equipment to extract air from the packaging, completely blocking oxygen from coming into contact with the apple. This method has the best preservation effect and can maintain the freshness of apples for a long time, but it requires professional equipment and is suitable for commercial use or large-scale preservation needs.

When consuming apples in daily life, it is recommended to cut and eat them immediately. If preservation is needed, it is recommended to choose refrigeration or lemon juice processing. Although the color of apples changes after oxidation, it does not affect their safety for consumption, only some nutrients such as vitamin C will be lost. For long-term storage of apples, it is recommended to choose intact and uncut fruits, store them in a cool and ventilated place, and avoid storing them together with fruits that release large amounts of ethylene, such as bananas. Reasonable selection of antioxidant methods can maximize the preservation of the nutritional value and taste of apples.