Why doesn't an apple oxidize after being cut

Oxidation after apple cutting is a normal phenomenon, which can be delayed by soaking in salt water, covering with plastic wrap, using lemon juice, refrigeration, vacuum sealing, and other methods.

1. Soaking in Salt Water

Soak the cut apples in light salt water for about 1 minute. Salt can inhibit polyphenol oxidase activity and slow down browning of the flesh after contact with oxygen. Note that the concentration of salt water should not be too high to avoid affecting the taste. After soaking, rinse the surface salt with clean water.

2. Cover with cling film

Wrap the cut surface tightly with cling film to isolate air contact. Choose food grade PE plastic wrap to ensure complete and seamless adhesion. This method is suitable for short-term storage, and it is recommended to consume it within 2 hours to avoid prolonged sealing that may cause moisture condensation and affect the taste.

3. Using lemon juice

citric acid can effectively inhibit oxidase activity. Dilute fresh lemon juice with water in a ratio of 1:3 and spray or lightly brush the apple slices. The reducing properties of vitamin C can delay browning. This method is suitable for ready to eat scenarios, but may cause a slight sour taste. Children or those with excessive stomach acid should use it in moderation.

4. Refrigerated storage

Low temperature environment can reduce enzyme activity. Putting sliced apples in a sealed box and placing them in a refrigerator at 4 ℃ can extend the preservation time to 4-6 hours. Be careful not to mix with other foods with strong odors. Apples that have been refrigerated have a crisper and more refreshing taste, but should not be repeatedly removed and reheated.

5. Vacuum sealing

Use a vacuum machine to remove the air inside the packaging and completely block the oxidation reaction. Vacuum processed apple chunks can remain non browning for 24 hours under refrigeration conditions, making them suitable for bulk meal preparation. Please note that vacuum packaging may slightly alter the texture of the fruit pulp. It is recommended to pair it with yogurt or salad. Although apple oxidation does not affect food safety, it can reduce vitamin C content. During daily processing, priority can be given to antioxidant varieties such as Red Fuji, and ceramic knives can be used to reduce metal ion catalysis during cutting. If long-term storage is required, apples can be mixed with other fruits rich in vitamin C to delay oxidation through synergistic effects. Before consumption, observe whether it has spoiled, if there is an odor or obvious softness, it should be discarded.