How to prevent fruits from oxidizing

Fruit oxidation can be delayed through physical isolation, acidic soaking, low-temperature storage, and other methods. The oxidation of fruits is mainly due to the oxidation of phenolic substances upon contact with oxygen, resulting in darkening of color and loss of nutrients.

1. Physical isolation

Using cling film to tightly wrap the cut surface or storing fruits in sealed containers can effectively reduce contact with oxygen. After cutting open easily oxidizable fruits such as apples and pears, immediately cover them with plastic wrap to maintain their color for several hours. Vacuum packaging technology can more thoroughly isolate air and is suitable for commercial storage.

2. Acidic soaking

Soak sliced fruits in light salt water or lemon water to inhibit polyphenol oxidase activity in an acidic environment. Add 5 grams of salt to 500 milliliters of water or squeeze in half a lemon juice, soak for 3 minutes. This method has significant effects on tropical fruits such as pineapple and mango.

3. Low temperature storage

4 ℃ refrigeration can reduce enzyme activity and slow down oxidation rate. Bananas, strawberries, and other fruits that are sensitive to low temperatures should be stored in fresh-keeping boxes to avoid frostbite. Air conditioned refrigerated trucks are used in commercial transportation to extend the shelf life by controlling the temperature and gas ratio.

4. Pre treatment

Boiling water for 10 seconds can destroy the structure of oxidase, suitable for peach, apricot and other stone fruits. After steaming and cooking, the cell walls of fruits soften, making them easier to make into muddy complementary foods. Dehydration and drying treatment can completely prevent oxidation reactions and preserve most of the nutrients in dried fruits.

5. When consumed in combination with citrus fruits that are high in vitamin C, their antioxidant properties can protect easily oxidizable fruits. Mixing avocado with lemon juice or dipping apple slices in honey can form an antioxidant barrier. The tannic acid in pomegranate juice also has a significant antioxidant effect.

When processing fruits in daily life, physical isolation and acidic soaking methods are preferred, which are easy to operate and do not affect the taste. When long-term storage is required, low-temperature and dehydration treatment can be combined, but some water-soluble vitamins may be lost. Note that fruits with high enzyme content such as mangoes and papayas oxidize faster. It is recommended to cut and eat them immediately. Special populations such as those with excessive stomach acid should control the frequency of using the acid soaking method to avoid stimulating the gastrointestinal mucosa.