How to make fruits that are not oxidized

The fruits in the fruit scoop can be delayed in oxidation by soaking them in acidic liquids, reducing exposure time, and selecting varieties that are not easily oxidized. The oxidation of fruits is mainly due to the browning reaction caused by the contact between polyphenol oxidase and oxygen. The key controlling factors include isolating air, reducing enzyme activity, and regulating acidity and alkalinity.

1. Acidic soaking

Soaking cut fruits in lemon juice or diluted salt water can effectively delay oxidation. Citric acid and vitamin C have reducing properties and can inhibit the activity of polyphenol oxidase. The ratio of 1 part lemon juice to 3 parts water should be used, and the soaking time should be controlled within 2 minutes. Prolonged soaking may affect the taste. Pineapple juice, orange juice, and other fruit juices containing natural antioxidant components can also be used as soaking solutions.

2. Air isolation

Tightly wrapping the cut surface with cling film or vacuum sealing can block oxygen contact. Fruit chunks should be immediately placed in a sealed box to reduce exposure to air. You can place absorbent paper at the bottom of the container to absorb the juice, and cover the surface with wet kitchen paper to maintain humidity. When placing in layers, use baking paper to separate them to avoid mechanical damage caused by stacking.

3. Low temperature treatment

refrigeration environment can significantly slow down the enzymatic reaction rate, and storage below 4 ℃ can reduce the oxidation rate by more than half. Pre processed fruits should be placed in the refrigerator as soon as possible, but tropical fruits such as bananas should not be kept below 10 ℃. Although freezing can completely inhibit oxidation, the texture will become soft after thawing, making it suitable for subsequent heating and consumption of fruits.

4. Variety selection

Apples, pears, and other easily oxidizable fruits should be treated last, with priority given to using antioxidant varieties such as strawberries, grapes, and citrus fruits. Red meat dragon fruit, mango and other fruits containing anthocyanins not only prevent browning, but also increase color. Applying olive oil to the cut surface of avocado can form a protective film, while preserving the entire stem of banana can delay oxidation.

5. Preprocessing Techniques

Use a ceramic knife to cut and reduce metal ion catalysis, ensuring uniform block size and consistent treatment effect. Blanching in boiling water for 5 seconds can completely inactivate oxidase, but it may result in the loss of some water-soluble nutrients. Soaking honey in water can form a sugar film to block oxygen, but it will change the sweetness. Patients with diabetes need to use it carefully.

When making fruit scoops, it is recommended to first deal with oxidation resistant varieties and cut and use fruits that are prone to browning. Choose glass or ceramic containers to contain and avoid metal containers accelerating the reaction. Paired with acidic substrates such as yogurt and coconut milk can extend the shelf life, but it should be consumed within 2 hours. If long-term storage is required, different fruits can be processed separately and mixed before consumption. Please note that fruits such as mangoes and pineapples that may cause allergies should be labeled separately, and children's consumption should be monitored by adults.