The joy of farmers markets around the world is a fresh tomato in season, and that season is beginning in the Rio Grande Valley. Botanically speaking, solanum lycopersicum is a fruit that is technically classified as a berry since it develops from the ovary of a vine plant, and contains seeds and pulp within it. Visualize cranberries, grapes, and watermelon and consider the general similarity of structure.

Fruit it may be, but on May 10, 1893, the United States Supreme Court declared the tomato a vegetable for purposes of trade, since it was commonly eaten as part of a main course and not as a dessert. As you celebrate the 117th anniversary of this decision next Monday, ponder the fact that the tomato is a member of the solanaceae, or nightshade family, along with eggplant, potatoes, sweet and hot peppers, and tobacco. A native of the western side of South America, the tomato was already being cultivated in Central America and Mexico when the Spanish arrived. Tomato plants were taken back to Spain in the 16th century, and soon spread throughout the rest of Europe, Asia, the Middle East, and North America. However, in some areas they were thought to be as poisonous as their nightshade cousins, and were consequently used only as decorative plants.

Fresh, vine-ripened tomatoes have an unbeatable nutritional profile. They are rich in vitamins A, C and K; are a good source of vitamins B1, B2, B3, B6, and E, in addition to minerals such as chromium, potassium, magnesium, and iron; and are an excellent source of dietary fiber. As you may remember from our discussion of eating by color, their red pigment is a clue to their high levels of lycopene and other beneficial antioxidants.

Commercially available tomatoes are often picked green and ripened with ethylene gas in warming rooms. Ethylene is a hydrocarbon gas that many fruits produce as a cue to start the ripening process. Tomatoes ripened under such artificial methods will keep longer but will have poor flavor and a starchier texture than the plant-ripened tomatoes available at farmers markets. At the market, choose tomatoes that have rich color (appropriate for their variety), smooth skin that is free from blemishes, are heavy for their size, and are sweetly aromatic. The fragrance of a naturally ripened fresh tomato is simply unforgettable.

Always store tomatoes at room temperature, out of direct sunlight, and use them within a few days. Avoid refrigerating them; cold temperatures kill their flavor, and turn the flesh pulpy. Unripe tomatoes can be ripened by placing them in a pierced paper bag along with an apple or a banana for a few days at room temperature.

Tomatoes can be blackened to bring out more robust and complex flavors, a method particularly appropriate for making cooked salsas. They can also be slow roasted with garlic and a drizzle of olive oil; a good way to make use of ripe tomatoes that won’t keep much longer.

Whether you prefer them raw or cooked, buy your tomatoes at the Harlingen Farmers Market, every Saturday from 3 - 4:30 p.m., 712 N. 77 Sunshine Strip in the courtyard at El Mercado Mall.