Brussels sprout

Brussels sprout
Brussels sprouts, cultivar unknown
Details
Species	Brassica oleracea
Cultivar group	Gemmifera group
Origin	Low Countries, year unknown
Cultivar group members	Cabbage

The Brussels sprout is a cultivar in the Gemmifera group of cabbages (Brassica oleracea), grown for its edible buds. The leafy green vegetables are typically 2.5–4 cm (0.98–1.6 in) in diameter and look like miniature cabbages. The Brussels sprout has long been popular in Brussels, Belgium, and may have originated there.^[1]

Cultivation

Forerunners to modern Brussels sprouts were likely cultivated in ancient Rome. Brussels sprouts as we now know them were grown possibly as early as the 13th century in what is now Belgium.^[2] The first written reference dates to 1587.^[2] During the 16th century, they enjoyed a popularity in the southern Netherlands that eventually spread throughout the cooler parts of Northern Europe.

Brussels sprouts grow in temperature ranges of 7–24°C (45–75°F), with highest yields at 15–18°C (59–64°F).^[3] Fields are ready for harvest 90 to 180 days after planting.^[2] The edible sprouts grow like buds in helical patterns along the side of long, thick stalks of about 60 to 120 cm (24 to 47 in) in height, maturing over several weeks from the lower to the upper part of the stalk. Sprouts may be picked by hand into baskets, in which case several harvests are made of five to 15 sprouts at a time, or by cutting the entire stalk at once for processing, or by mechanical harvester, depending on variety.^[2] Each stalk can produce 1.1 to 1.4 kg (2.4 to 3.1 lb), although the commercial yield is about 900 g (2.0 lb) per stalk.^[3] In the home garden, "sprouts are sweetest after a good, stiff frost".^[4]

Brussels sprouts are a cultivar of the same species as cabbage, in the same family as collard greens, broccoli, kale, and kohlrabi; they are cruciferous (they belong to the Brassicaceae family; old name Cruciferae). They contain good amounts of vitamin A, vitamin C, folic acid and dietary fibre. Moreover, they are believed to protect against colon cancer, because they contain sinigrin.^[5] Although they contain compounds such as goitrin that can act as goitrogens and interfere with thyroid hormone production, realistic amounts in the diet do not seem to have any effect on the function of the thyroid gland in humans.^[6]

Breeding research conducted by Syngenta in the Netherlands focusing on compounds known as glucosinolates found in Brussels sprouts has resulted in reduced bitterness and in improved health attributes. These improvements in reducing unpleasant taste through scientific breeding advances have been credited with spurring a "renaissance" and growth in production and consumption of Brussels sprouts hybrids.^[7]

Europe

In Continental Europe, the largest producers are the Netherlands, at 82,000 metric tons, and Germany, at 10,000 tons. The United Kingdom has production comparable to that of the Netherlands, but it is not generally exported.^[8]

North America

Production of Brussels sprouts in the United States began in the 18th century, when French settlers brought them to Louisiana.^[3] Thomas Jefferson grew them at Monticello.^[9] The first plantings in California's Central Coast began in the 1920s, with significant production beginning in the 1940s. Currently, several thousand acres are planted in coastal areas of San Mateo, Santa Cruz, and Monterey counties of California, which offer an ideal combination of coastal fog and cool temperatures year-round. The harvest season lasts from June through January.^[2][10] They are also grown in Baja California, Mexico, where the harvest season is from December through June.^[10]

Most of the United States production is in California,^[9] with a smaller percentage of the crop grown in Skagit Valley, Washington, where cool springs, mild summers and rich soil abounds, and to a lesser degree on Long Island, New York.^[11] Total United States production is approximately 32,000 tons, with a value of $27 million.^[3] Ontario, Canada produces about 1,000 tons per year.^[12]

About 80% to 85% of US production is for the frozen food market, with the remainder for fresh consumption.^[11] Once harvested, sprouts last three to five weeks under ideal near-freezing conditions before wilting and discolouring, and about half as long at refrigerator temperature.^[3] American varieties are generally 2.5–5 cm (0.98–1.97 in) in diameter.^[3]

Nutritional and medicinal value

Brussels sprouts, as with broccoli and other brassicas, contains sulforaphane, a chemical believed to have potent anticancer properties. Although boiling reduces the level of the anticancer compounds, steaming and stir frying do not result in significant loss.^[13]

Brussels sprouts and other brassicas are also a source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.^[14][15]

Consuming Brussels sprouts in excess may not be suitable for heart patients taking anticoagulants since they contain vitamin K. In one such reported incident,^[16] doctors determined that the reason for a heart patient's worsening condition was eating too many Brussels sprouts.

Cooking and preparation

The most common method of preparing Brussels sprouts for cooking begins with cutting the buds off the stalk. Any surplus stem is cut away, and any loose surface leaves are peeled and discarded. Once cut and cleaned, the buds are typically cooked by boiling, steaming, stir frying, grilling, or roasting; however, boiling results in significant loss of anticancer compounds.^[13] To ensure even cooking throughout, buds of a similar size are usually chosen. Some cooks will make a single cut or a cross in the center of the stem to aid the penetration of heat. Brussels sprouts can be pickled as an alternative to cooking.

Overcooking will render the buds gray and soft, and they then develop a strong flavour and odour that some dislike.^[9] The odor is associated with glucosinolate sinigrin, an organic compound that contains sulfur: hence the strong smell.

For taste, roasting Brussels sprouts is a common way to cook them in large quantities that seems to bring out the flavor that school children can enjoy.^[17] One school district served roasted and pickled Brussels sprouts to 20,000 children who reportedly enjoyed the food during a single day.^[18]

Common toppings or additions for Brussels sprouts include balsamic vinegar, apple cider vinegar, bacon, pistachios, pine nuts, mustard, brown sugar, and pepper.

Gallery

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  A field of Brussels sprouts after harvest

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  Brussels sprouts on the stalk

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  Brussels sprouts on stalks

References

External links

Wikimedia Commons has media related to Brassica oleracea var. gemmifera.

• PROTAbase on Brassica oleracea (Brussels sprouts)
• Cultural information on brussels sprouts for the home garden from the experts at Learn2Grow
• Brassica oleracea gemmifera - Plants For a Future database entry
• Brussels sprouts nutrition
• Brussels sprouts recipes - informative articles and recipes on Brussels sprouts