How can apples not oxidize

After cutting an apple, oxidation can be delayed by soaking it in salt water, covering it with plastic wrap, using lemon juice, refrigerating it, vacuum sealing, and other methods. The browning reaction of apple flesh after contact with air is mainly catalyzed by polyphenol oxidase, which can effectively block or slow down the oxidation process.

1. Soaking in Salt Water

Soak the cut apples in light salt water for about 1 minute. Sodium ions in the salt water can inhibit polyphenol oxidase activity. This method is easy to operate and does not affect the original flavor of apples, making it suitable for ready to eat scenarios. Note that the concentration of salt water should not be too high to avoid apples absorbing too much sodium salt.

2. Cover with cling film

Tightly wrap the cut surface with cling film to isolate air contact and physically block oxidation reactions. It is recommended to choose food grade PE plastic wrap for better air release during wrapping. This method is suitable for short-term storage, but may affect the integrity of the fruit pulp due to squeezing.

3. Using lemon juice

The vitamin C and acidic environment in lemon juice can effectively inhibit enzymatic browning. Fresh lemon juice can be diluted with water in a ratio of 1:3 and sprayed onto the surface of apples, or directly applied. This method will give apples a slightly sour flavor and is suitable for making dishes such as fruit salads.

4. Cold storage

Low temperature environment can significantly reduce polyphenol oxidase activity, and placing sliced apples in a refrigerator at 4 ℃ can delay oxidation for 6-8 hours. It is recommended to put the apples in a sealed container to avoid cross flavors. Before consumption, they can be restored to room temperature to enhance the taste. This method has the least impact on the texture of apples.

5. Vacuum sealing

uses vacuum equipment to extract oxygen from the packaging, fundamentally blocking oxidation conditions. Vacuum processed apple chunks can remain non browning for 24 hours under refrigeration conditions, but professional equipment support is required. Suitable for batch pre-processing or long-term storage needs in the catering industry.

When consuming apples in daily life, it is recommended to choose freshly cut and eaten. If preservation is needed, it is recommended to use the above methods in combination. Processed apples should be consumed as soon as possible to avoid repeated exposure to air. For young children or special populations, it is recommended to choose physical isolation to reduce exposure to additives. Keeping the cutting board clean can also reduce the oxidation rate, and using ceramic knives during cutting can slow down metal ion catalytic reactions. Long term storage can consider making dried apples or jam, which can completely destroy oxidase activity through dehydration or high temperature.