You Say Tomato

With so much disagreement over the pronunciation of "tomato," imagine the fights that would ensue over Lycopersicon esculentum, the tomato's scientific name. However, pronunciation is just one debate over this colorful fruit ... vegetable ... food.  

Botanically speaking, tomatoes are fruits; the edible part of a plant containing its seeds. In 1893, a dispute between fruit importers and import duty collectors resulted in the U.S. Supreme Court ruling -- based on consumers' perceptions and common serving practices -- that tomatoes were vegetables.

As part of the family Solanaceae, tomatoes are related to the eggplant, red pepper, potato, ground cherry and tomatillo. Tomatoes were first cultivated in the West by the Aztecs and Incas as early as 700 A.D. Today, tomatoes are one of the most widely grown and commercially important crops in the world.  

Once considered poisonous, today tomatoes are hailed for their health benefits. One medium-sized tomato (about 148 grams) is a good source of vitamins A and C, and potassium. They also contain small yet notable amounts of iron and fiber, and are low-calorie, low-fat and even low-carb (about 6 grams per 5-oz. tomato). Tomatoes surpass all vegetables and fruits in total carotenoids. In 1995, researchers at Harvard University, Boston, recognized a link between tomato consumption and reduced cancer risk.

Tomatoes are rich in lycopene, the subject of much research in recent years. Studies have demonstrated lycopene's effectiveness at reducing the risk of prostate cancer, colorectal cancer and other digestive-tract cancers. Studies also show that it may protect against endometrial, breast and lung cancers. Consumption of heat-processed tomatoes appears to yield the highest amount of lycopene absorption. Adding a small amount of fat during heat processing further increases the available lycopene by "dissolving" it and making it more readily absorbed into the bloodstream.  

Today, hundreds of tomato varieties exist. They often are categorized based on size, shape, color, moisture and taste, although the terms used vary.  

Cherry tomatoes are similar in size to cherries (with a diameter of approximately 1 in.). Whether yellow, orange or red, they are wonderful for off-the-vine snacking or as a garnish. These healthy little snacks can also be stuffed with smoked oysters or slow-roasted with goat cheese.  

Paste tomatoes, like the classic Roma or Italian plum tomato, can vary in size and shape, but are larger than cherry tomatoes. Varieties such as 'Jersey Devils' can be very elongated-looking, like banana peppers, while regular plum tomatoes are round like their namesake. Most people, however, associate Roma tomatoes with a slightly elongated shape. More pulp and less moisture than larger tomatoes makes them rich and flavorful, ideal for cooking down into sauce, and good for baking or oven-roasting in various cooked dishes. Although certain varieties generally are better suited for canning, commercial canners/processors will utilize a variety of "their favorites" based on growing conditions and other characteristics.

With the larger tomatoes, some argue that midsize tomatoes, such as the 'Better Boy' or 'Better Bush,' are the most flavorful. At 6 to12 oz., they grow in the largest array of colors, and have a rich taste and juicy texture. They are a favorite for slicing onto sandwiches, and making salsas and soups -- anywhere a hearty tomato taste is desired. Varieties that grow with increased moisture levels will require longer draining and cooking times when used in prepared dishes.

Beefsteak tomatoes are the largest, ranging from 1 to 4 lbs. and as large as 6 in. in diameter. Although they usually exhibit many cuts and warts, these ugly ducklings provide a tasty topping, and yield enough slices to cover the biggest hoagies, grinders or deli sandwiches.  

Heirloom tomatoes also are quickly gaining popularity at the foodservice level, as they represent numerous varieties that have been selectively grown for specific characteristics and passed down for several generations.  

So, what's in the "perfect tomato?" Most would agree that vine ripening is the foremost factor. Most commercial fresh tomatoes are picked "green," as fully ripened tomatoes are too soft to withstand transport. Green tomatoes ripen in transit by exposure to ethylene gas. While this produces a ripe-looking tomato, the taste and texture differ from a vine-ripened product. In addition, most commercial products are refrigerated, which leads to mealy texture and flavor deterioration. Many foodservice professionals prefer the taste of canned tomatoes, which are picked at the peak of ripeness immediately prior to processing.  

Processed tomatoes are almost as varied as those off the vine. The Code of Federal Regulations (CFR) defines canned tomatoes as "the food prepared from mature tomatoes" (21 CFR, Pt. 155, Sec. 90-91). They may be whole, diced, sliced or in wedges, and can be packed with one or more approved ingredients, such as calcium salts to increase firmness; organic acids; sweeteners to temper the tartness of added acid; or spices and flavorings.

Stewed tomatoes contain up to 10% added vegetable ingredients, such as onion, peppers and celery. Packing media further distinguish canned products as "Tomato Purée or Pulp" having between 8% and 24% soluble tomato solids (21 CFR, Pt. 155, Sec.3), and "Tomato Paste" having not less than 24% soluble tomato solids.

Spray-dried tomato powders and dried flakes offer developers a low-moisture (typically below 4%, but as high as 7%) way to incorporate fresh-tomato taste and color into seasoning blends and dry mixes for sauces, soups and beverages. A traditional technology, sun-drying, creates a 12% to 24% moisture product, by dehydrating ripe tomato pieces treated with sulfur dioxide on drying trays exposed to the sun for about a week.

The tomato has found application in endless regional and ethnic cooking styles, making it one of the most universally popular vegetables (or fruits) on the planet. And with innovative new uses continually arising, it's doubtful the rest of the fruit and veggie world will ever "ketch-up."

R. J. Foster earned a B.S. in Food Science from the University of Wisconsin- Madison, and has worked for over a decade in technical service and research and development in the food and meat industries. He can be contacted at [email protected].

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