What word does your mother always say?
late 14c., "keep safe," from Anglo-French preservare, Old French preserver, from Medieval Latin preservare "keep, preserve," from Late Latin praeservare "guard beforehand," from Latin prae "before" (see pre-) + servare "to keep safe" (see observe). As a treatment of fruit, etc., 1570s; of organic bodies from 1610s. Related: Preserved; preserving.
"fruit preserved with sugar," c.1600, from preserve (v.). Earlier it meant "a preservative" (1550s). Sense of "protected place for animals or plants" (a sense more properly belonging to conserve) is from 1807.