1. Moisture content: After dehydration, the moisture content of raisins is low, only about 2%, while the moisture content of fresh grapes is above 8%.

2. Sugar content: Because raisins are dehydrated, the sugar content is relatively high. The sugar in raisins is mainly fructose and glucose, while the sugar in fresh grapes is relatively low.

3. cellulose content: the cellulose content in raisins is relatively high, while the cellulose content in fresh grapes is relatively low. This is because the cellulose in raisins mainly comes from grape skin and pulp. In the process of dehydration, water is removed, but cellulose is retained.

4. Contents of vitamins and minerals: There are some differences in the contents of vitamins and minerals between raisins and fresh grapes. The contents of vitamin C and vitamin B in raisins are relatively low, while the contents of vitamin C and vitamin B in fresh grapes are relatively high. Similarly, the contents of potassium, iron and magnesium in raisins are relatively high, while those in fresh grapes are relatively low. Raisins are rich in cellulose, sugar and minerals, and are suitable as snacks to supplement energy and nutrition. Fresh grapes, on the other hand, contain more vitamin C and water, have lower sugar, and can provide more water and vitamins.