To prevent eggplant from oxidizing once you have cut it and to leach out the bitter tasting solanine, there are several techniques utilizing salt. One way is the salt-water method described in this recipe. Another way is to pour salt over the cut eggplant, place on a sheet pan lined with parchment paper, cover the eggplant with another piece of parchment, top with a second sheet pan and add weight such as canned goods or bags of dry beans. Place the pan in the refrigerator at least one hour or as long as overnight. Be sure to wipe the liquid and salt off before using in your preparation. It does not have to be dredged in salt, but you can be liberal with your application as you will be taking most of the salt off when you wipe it with a paper towel.