conserve

fruit preserved by cooking with sugar

keep constant through physical or chemical reactions or evolutionary change; "Energy is conserved in this process"

keep in safety and protect from harm, decay, loss, or destruction; "We preserve these archeological findings"; "The old lady could not keep up the building"; "children must be taught to conserve our national heritage"; "The museum curator conserved the ancient manuscripts"

use cautiously and frugally; "I try to economize my spare time"; "conserve your energy for the ascent to the summit"

preserve with sugar; "Mom always conserved the strawberries we grew in the backyard"