Sugar is a common preserve for jams and jellies.

A substance used to maintain the quality or condition of something, often in the context of food.
This jam is a delicious preserve.
Salt is a good preserve for meat.
Vinegar acts as a preserve for pickles.
fruit preserve
sweet preserve
homemade preserve
conservant
preservative
stabilizer
We should preserve the environment for future generations.

To keep something in its original state or in good condition.
Please preserve the food.
They preserve old buildings.
We must preserve our culture.
preserve food
preserve nature
preserve history
maintain
conserve
protect