Flavor chemistry of vegetables

Vegetables are edible plant products which can be modified stems, roots, leaves, flowers, or even fruits. They are usually classified on the basis of the part of the plant that is used for food. Stem vegetables include asparagus and kohlrabi while beets,carrots, radishes and turnips are root vegetables. Among the leaf and leafstalk vegetables are brussel sprouts, cabbage, celery, endive, kale, lettuce, rhubarb and spinach. The head or flower vegetables include artichokes, broccoli, and cauliflower. Garlic, leeks, and onions are classified as bulb vegetables. Botanically, the term "fruit" applies to the structure, usually containing seeds, which develops from the flower ovary after pollination and fertilization (Vaughan and Geissler, 1997). Therefore, beans, cucumbers, eggplant, okra, peppers, squash, sweet corn and tomatoes would be classified as fruits according to this definition. However, the important distinction between fruits and vegetables has come to be made on a usage basis; those plant products that are usually consumed with the main course of a meal are considered to be vegetables while those used mainly as desserts are considered fruits.