How to keep fruits from oxidizing

Preventing fruit oxidation can be achieved through physical isolation, soaking in acidic solutions, low-temperature storage, reducing cutting area, and selecting antioxidant ingredients. The oxidation of fruits is mainly due to the enzymatic browning reaction of phenolic substances upon contact with oxygen. By intervening in the oxidation conditions, the discoloration can be effectively delayed.

1. Physical isolation

Wrap the cut surface tightly with cling film or store the fruit in a sealed container, which can directly block oxygen contact. After cutting open easily oxidizable fruits such as apples and pears, immediately covering them with plastic wrap can maintain their color for several hours. Vacuum packaging technology can more thoroughly isolate air and is suitable for commercial use.

2. Acidic soaking

Soaking fruits in diluted vinegar or lemon juice solution can inhibit polyphenol oxidase activity in an acidic environment. Add 15 milliliters of lemon juice solution to every 500 milliliters of water, soak sliced fruits for 1-2 minutes to form a protective layer. Pineapple juice also has a similar effect due to its presence of bromelain.

3. Low temperature refrigeration

Low temperature environments below 4 ℃ can significantly reduce enzyme activity, and storing uncut fruits in fresh-keeping bags and refrigeration can delay oxidation for 3-5 days. Bananas and other tropical fruits should be stored at temperatures above 12 ℃, and the stems can be wrapped in kitchen paper to reduce ethylene release. Freezing storage can cause the oxidation reaction to essentially come to a halt.

4. Reduce Cut Surface

Whole fruit preservation is more resistant to oxidation than slicing, and when cutting, try to cut large pieces to reduce the exposed area. Apples can be pitted first and then sliced, while avocados can be stored with the core preserved. Using sharp knives can reduce cell damage and lower the probability of oxidase release.

5. Mix fruits with citrus fruits rich in vitamin C or onion shreds containing sulfur-containing compounds with antioxidants [SEP], which can block oxidative chain reactions through electron transfer. Adding pomegranate or grape seed extracts to salads also has a synergistic antioxidant effect. Honey coating can form a natural barrier on the surface of fruits.

It is recommended to prioritize the use of physical isolation when processing fruits in daily life, which is both safe and avoids affecting the taste. After soaking in acidic solution, rinse with clean water. People with sensitive gastrointestinal tract should use vinegar soaking method with caution. Long term storage can choose quick freezing, but the taste may change after thawing. Different types of fruits have significant differences in oxidation rates. Apples, bananas, and other fruits require special protection, while citrus fruits are more resistant to storage due to their inherent antioxidant content. Keeping tools and containers clean can also reduce the accelerated deterioration caused by microbial contamination.