Wrinkles, browning and soft spots are all signs that an eggplant has spoiled. An eggplant should be smooth, shiny and firm in all areas. Do not purchase eggplants that exhibit any of these signs of potential spoilage.
If an eggplant bruises after it is purchased, it is still safe for eating provided it has not begun to rot. Because rotting begins quickly after an eggplant bruises, use any damaged eggplants as soon as possible. Cut away the bruised area, and use the remaining portion of the eggplant. If rotted patches or mold are apparent after peeling and cutting, discard the entire eggplant.