What is the reason why fruits will lose their sweetness if stored for a long time?

The reason why the sweetness of fruits will decrease after being stored for a long time is mainly due to the respiration of the fruits themselves.

Respiration is a basic life phenomenon of organisms. It is opposite to photosynthesis and forms the "exhaust of the old and the new" of plants. During respiration, plants absorb oxygen from the environment, break down organic matter, release carbon dioxide and water, and release energy in the process.

For fruits, their respiration will decompose the sugar in the fruit, causing the sugar in the fruit to gradually decrease and the sweetness to decrease. At the same time, long-term storage will also cause the water in the fruit to gradually evaporate, making the fruit drier and affecting the taste.

Therefore, in order to maintain the freshness and sweetness of the fruit, it is recommended to eat it as soon as possible or store it properly.