How long does it take for an apple to oxidize when cut open

Apples usually start to oxidize and discolor after 5-10 minutes of cutting, and the oxidation rate is affected by factors such as environmental temperature, apple variety, and cutting method. After cutting open an apple, the meat is exposed to air, and the polyphenol oxidase in it reacts with oxygen, causing the flesh to gradually turn brown. The higher the temperature, the faster the oxidation reaction, and the color change rate at room temperature in summer may be shortened to 3-5 minutes. The degree of oxidation of different varieties of apples also varies, for example, red Fuji apples have relatively stronger antioxidant capacity, while green apples are more prone to discoloration. Cutting with sharp knives can reduce cell damage and has a slower oxidation rate than cutting with blunt knives. Soaking sliced apples in light salt water can delay oxidation, and a salt water concentration of around 3% is recommended. The vitamin C in lemon juice has a reducing effect, and applying it to the cut surface can delay browning for 1-2 hours. Vacuum sealed storage can completely isolate oxygen, and the oxidation rate will be reduced by more than half in a refrigerated environment. Some pre made apple slices that have undergone special treatment can maintain their color for 24 hours without changing by adding food grade antioxidants.

It is recommended to control the cutting amount according to the consumption needs, and cutting and eating immediately can best preserve nutrients. If storage is required, rinse the cut surface with cold water to reduce enzyme activity, and then tightly wrap it with cling film and refrigerate. Apples can still be safely consumed after oxidation, but some nutrients such as vitamin C may be lost. Prolonged exposure to oxidized apples may breed microorganisms, and it is not advisable to continue eating when the skin becomes sticky or has an unpleasant odor. Apples can be paired with oranges and kiwis that are rich in vitamin C in daily life, as an acidic environment helps to inhibit oxidative reactions.