點解加熱會破壞維他命c??

維生素 C, 又稱抗壞血酸。分子式 C6H8O6。
維生素 C 是一個強還原劑﹐在人體內扮演一個抗氧化劑, 使得人體組織之衰退和衰老得以延緩. 然而, 維生素 C 在水溶液中或受熱很容易被氧化﹐氧化時先失去兩個氫﹐生成去氫抗壞血酸﹕

圖片參考：http://i117.photobucket.com/albums/o61/billy_hywung/Ascorbicacid.jpg

在人體內維生素 C 通過上式的氧化還原體系參與體內的氧化還原反應﹐但去氫抗壞血酸經進一步氧化﹐分子碳鏈斷裂﹐生成其他物質﹐則完全失去它的還原能力。
Note: 去氫抗壞血酸英文為 "Dehydroascorbic acid"

Vitamin C is not fat-soluble and is easily destroyed by heat. So it cannot be stored in large amounts in the body.

However, for acids soluble in fats, it is harder to be destroyed by heat.

VITAMIN A,D,E,K are fat-soluble, so they are harder to be destroyed by heat and can be stored.

VITAMIN B,C are water-soluble, and are easily destroyed by heat.

Actually your question is related to Biology~~

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