Vitamin C is an important component that gives tea its nutritional value, and its content is closely related to tea quality.

Vitamin C is also a substance easily oxidized. The higher the grade of green tea, the higher its Vitamin C content, and the more difficult it is to preserve.

When Vitamin C is oxidized, it generates dehydroascorbic acid, which interacts with amino acids to form aminocarbonyl compounds. This not only reduces the nutritional value of the tea but also causes the color to turn brown and diminishes the fresh, brisk taste.

If green tea retains over 80% of its Vitamin C content, its quality remains unchanged; once it drops below 60%, the quality noticeably deteriorates.