Eating fruit is an everyday occurrence, but drinking it as juice seems quite fashionable. However, after buying a juicer, many people have the same questions: Does juicing lead to a loss of nutrients? How should I juice properly? And how long can the juice be stored? Cucumber juice loses 80% of its Vitamin C
First, even if you drink the juice immediately after juicing, a significant portion of the nutrients will be lost. This is because the cells of fruits and vegetables contain complex ultrastructures. Think of it like an office building with many rooms; each room has its own function and contains different things that cannot be mixed. For example, Vitamin C must not meet various oxidizing enzymes, or they will interact with each other. However, during juicing, the high-speed rotating blades destroy all the cells, mixing everything together. As a result, Vitamin C comes into contact with multiple oxidizing enzymes and is naturally severely depleted. An experiment conducted by one of my students showed that the destruction rate of Vitamin C in cucumber juice after blending was as high as 80%, with similar results for tomatoes, bok choy, and others.
In addition to Vitamin C, antioxidant components like flavonoids and anthocyanins will also be lost to varying degrees. As for insoluble fiber, it naturally does not end up in the juice. Insoluble elements like calcium are also left in the pulp. If possible, it's best to consume the pulp along with the juice. Blanching before juicing preserves nutrients
Many people don't know that in commercial production of fruit and vegetable juices, the produce is often blanched. This means the fruits and vegetables are briefly scalded in boiling water to "kill" the oxidizing enzymes and slightly soften the tissue before juicing. This not only reduces the loss of vitamins and increases the juice yield but also makes the juice color more vibrant and less likely to turn brown. This is especially important for vegetables without a sour taste, such as carrots, greens, celery, and sweet corn, which must be blanched before juicing.
As for the feeling of fullness you get from whole fruits and vegetables, this cannot be retained no matter how you juice them. Therefore, for those trying to lose weight, it's better to eat them whole; juicing is not an ideal choice. Fresh juice can be stored for up to one day
If the juice has not been blanched, it should be consumed immediately after juicing and cannot be stored. You could say that with every passing minute, the loss of vitamins and antioxidant components increases. If the juice is made from blanched produce, the enzymes have been inactivated, so it can be stored in a sealed container in the refrigerator for about a day. However, try to minimize the contact between the juice and air to prevent oxidation and browning.
Blanched juice is very prone to turning brown. Turning brown does not mean it is toxic or harmful; it is still drinkable. It only indicates that the health-promoting polyphenols in the fruit and vegetable have been oxidized upon contact with oxygen, and their antioxidant properties will be somewhat reduced. At the same time, during storage, the flavor will also gradually change, losing its original fresh and delicious taste.