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History
It is widely believed that the tomato, Lycopersicon
exculentum (1), was first domesticated in Mexico, where a variant of the wild cherry tomato was brought into cultivation.
Europeans were introduced to the tomato in the mid-16th century, and generally reacted with fear and scorn, due largely to
the tomato's membership in the family Solanacea, which includes many poisonous species such as the deadly nightshade. The
Italians, however, soon embraced the tomato, dubbing it pomi d'oro (golden apple) and adopting it into their cuisine. The
French gave this new fruit an even more romantic name: pomme d'amour (love apple). Still, it was not until the 1830s that
the tomato was much more than a curiosity in England or America. Today, the tomato is known as the pomodoro in Italy, as the
tomate in France, Germany, and Spain, and as the tomaat in Holland.
Although chefs in New Orleans were commonly using
the tomato by 1800, it took until the 1830s for it to catch on in New England. Within a decade the tomato became widely recognized
for its nutritional value(2), and even attributed medicinal qualities which it probably did not deserve. Tomato processing
began in 1847, when Harrison Woodhull Crosby, the chief gardener at Lafayette College developed a crude method of canning
tomatoes. Prior to 1890 all tomato canning was done by hand. Industry techniques improved with canning technology, and tomato
juice came on the market with the development of the juice extractor in the 1920s. In the late 1960s, mechanical harvesting
became a reality, this drove the industry to develop better techniques of bulk handling and processing.
Today, the
United States produces over 10 million tons of processing tomatoes, with California processing over 90% of the total.
Processing
Most
of the volume of processed tomatoes is packaged as bulk tomato paste. Packed in 50-gallon drums or in lined boxes weighing
over 3,000 lbs, the paste is usually shipped from the processing plant to other manufacturing sites. There it is used to make
a myriad of other products including ketchup, juice, soups, and sauces. Tomato paste produced in the United States is 100%
tomato; the raw tomato is simply cooked, separated from its skin and stems, and then boiled to a consistency of approximately
30% tomato solids to 70% water. A major concern in the production of tomato products is the preservation of pectin. Pectin
is a natural constituent of ripe tomatoes. It is formed between the microscopic cells, which make up the fleshy red tissues,
cementing these together. The more pectin is retained, the thicker the final product; thus it is a great concern in the manufacture
of "thick" products such as ketchup. To prevent the loss of pectin, tomatoes must be heated very rapidly once they have been
chopped or otherwise disturbed. This inhibits the action of pectic enzymes, another natural constituent of tomatoes. The industry
utilizes a large cooker known as a Hot Break to perform this task. The hot break works on the principle that a stream of cold
product (the raw tomatoes) will heat very rapidly when entering a large volume of very hot (210 degrees Fahrenheit is common)
tomatoes. There are some tomato products, such as juices and soups, where thickness is not the most sought after quality.
Instead, the emphasis is often on color and flavor. In processing these products the hot-break temperatures are set lower
(around 150 degrees), and the paste is commonly referred to as Cold Break.
Nutrition
Tomatoes are high in potassium
and vitamins A and C, and are cholesterol-free. In fact, recent scientific studies(3) indicate that eating cooked tomatoes
reduces one's likelihood of suffering from cholesterol-related heart problems and digestive-tract cancers. Why cooked tomatoes?
Cooking tomatoes releases lycopene, a strong antioxidant, from the skin of the tomato.
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