Eggplant, also called an aubergine, is now in season as a ‘fresh from the garden’ vegetable. For many Americans, it is an underused vegetable even though it is highly versatile. It can be grilled, stuffed, roasted, and stir-fried and also used in soups, stews, curries, and kabobs. Eggplant is nutritious, low in calories, fat, and sodium while high in fiber and nutrients such as potassium, magnesium, folic acid, Vitamin B6 and A. Eggplants are also recognized as a source of phenolic compounds that act as antioxidants. All of this “goodness” helps with maintaining good blood cholesterol, cognitive function, weight, and eye health and preventing cancer and heart disease. As such it is a big component of vegetarian and Mediterranean diets; it is also a family favorite and we are fortunate to have a number of varieties in our garden to enjoy.
While this vegetable provides so much good, many shy away from it because they detect a “bitterness” in it or have heard that the fruit is bitter. A young, freshly picked eggplant with smooth, glossy skin and intense color will have no bitterness whatsoever if consumed soon after picking. Old or overripe eggplants or those that are off color or sit out for a while after being harvested are more likely to exhibit a bitter flavor. Therefore, choose eggplants that are heavy, shiny and firm and avoid eggplants that are off-colored and/or do not exhibit a bright, glossy color. The seeds of a young, fresh eggplant are very small, so the flesh will not have accumulated the bitter compounds found in eggplants that have become overripe and rubbery.
If bitterness should be of concern, there are some actions one can take to eliminate it.
Begin by peeling the skin to remove any bitter compounds present in the skin or between the skin and the flesh.
“Sweating” an eggplant with salt will draw out the compound solaine, the chemical found in the seeds and flesh that contributes to the bitterness; it will also draw out some of the moisture making the eggplant more tender. To do this, slice, dice, cube, etc the eggplant and sprinkle the pieces with salt. (Canning and pickling salt is best, but any salt will do.) Allow the eggplant to set for 30 or more minutes, rinse off the salt, pat dry, and continue to prepare. Sweating an eggplant will also reduce the amount of oil it will absorb during cooking, too.
If salt is a dietary problem, another method used to remove bitterness is to soak the eggplant pieces in milk for 30 minutes prior to cooking. Drain off the milk and prepare the eggplant normally. Some feel that removing the seeds from the flesh is helpful. This may be of some use in an older eggplant as the seeds enlarge with age thereby increasing bitterness. To remove the seeds, slice the eggplant length-wise and use a spoon to scrap out as many seeds as possible.
In an ideal world, the eggplant is used the day of harvest and is fine on the counter short term. For longer storage, eggplants can be refrigerated for about a week as long as they don’t get too cold or damp. They should be stored in the refrigerator crisper drawer in a perforated plastic bag. I find it helpful to also wrap it in a paper towel before placing in the bag; the thin skin is highly susceptible to moisture damage so the paper towel helps with that. It can be sliced or cubed, then blanched or steamed, and frozen up to eight months for later use.
Eggplant should be cooked as it has chemicals that can cause digestive upset if eaten raw. Since the flesh discolors quickly, use right away after cutting. Lightly sprinkling raw eggplant with lemon juice helps to prevent browning. Eggplant is best cut with a stainless steel knife since carbon blades will cause discoloration. Cooking in an aluminum pan also will cause blackening. Eggplant fruits should be handled with care as they do bruise easily and those flaws quickly turn bad; a bruised eggplant will exhibit brown, corky flesh in the affected area.
Eggplant is a member of the nightshade family, same plant family as tomatoes and peppers. There are many varieties of eggplant in numerous colors and sizes. To learn more about eggplant, check out the eggplant fact sheet from the National Garden Bureau. (This site has fact sheets on other vegetables that may be of interest, too.) Visit ISU Extension and Outreach’s Quickinars, 5-15 minute online lessons, of seasonally appropriate topics for the garden, food preparation and food preservation to also learn more about gardening and how to use garden produce.