Broccoli

Broccoli

Key Facts

  • Broccoli is a member of the mustard family of plants and is closely related to Brussels sprouts, cabbage, cauliflower, kale, and kohlrabi.
  • Several broccoli-related product recalls have been reported, all associated with contamination with Listeria monocytogenes.
  • There are two forms of broccoli: sprouting broccoli, and heading broccoli. Sprouting broccoli is the form most commonly grown in the United States.
  • The U.S. is the 3rd largest producer of broccoli in the world, with California leading in U.S. production (90%).
  • The majority of U.S. broccoli is harvested from mid-October through December, though crops can also be harvested through April.
  • Broccoli is harvested for fresh consumption or processing, depending on factors such as current market value. There is no way to mechanically harvest broccoli, so it must be harvested by hand.
  • Optimal storage life for broccoli is 21-28 days. 
  • The average annual per capita consumption of broccoli in the United States is 5.8 pounds.
  • Broccoli provides an excellent source of vitamin K, vitamin C, chromium, and folic acid.
  • Phytonutrients are highly concentrated in broccoli, especially glucosinolates, which are under scientific investigation for their role in cancer prevention.
broccoli
Broccoli Sprouts

Introduction

Broccoli (scientific name: Brassica oleracea var botrytis) is a member of the Brassicaceae plant family, also known as the mustard family.Other familiar plants in the species Brassica oleracea include Brussels sprouts, cabbage, cauliflower, kale, and kohlrabi. Broccoli is a derivative of cabbage, and was selected for its edible, immature flower heads. The flower buds are green or purple, are picked before they open, and are eaten raw or cooked. Broccoli sprouts are also edible, consumed raw, and are a popular health food in the United States.

There are two distinct forms of broccoli: sprouting broccoli, and heading broccoli. Sprouting broccoli is the form most commonly grown in the United States. It is characterized by its branching cluster of green flower buds atop a thick, green flower stalk, with smaller clusters that arise like sprouts from the stem. The other form of broccoli is called heading broccoli and makes a dense, white curd similar to cauliflower. 

Broccoli
Calabrese Broccoli

Broccoli originated in the Mediterranean region where it has been cultivated since Roman times, but is a relatively new crop to the United States. The first commercial broccoli crop grown in the US was started in California in 1923, but Broccoli did not become a significant commercial crop in the US until after World War II.,

The United States is now the 3rd largest producer of broccoli in the world. According to the United States Department of Agriculture National Agricultural Statistics Service, in 2014 the United States produced 2 billion pounds of broccoli with a value of over 800 million dollars, grown on 129,000 acres of land. Most of the broccoli harvested in the U.S (90%) is grown in California, and 15-20% of U.S.-produced broccoli is exported to Canada, Japan, and Taiwan.

Foodborne Outbreaks

Romanesco Broccoli
Romanesco Broccoli

While there have not been many reported broccoli related foodborne illness outbreaks, broccoli salad kits were recalled in 2013 and ready-to-eat pork and chicken meals were recalled in 2011; both recalls were due to concerns of contamination of broccoli with Listeria monocytogenes.

To contribute to the Broccoli-associated Foodborne Outbreak section, please follow this link: http://fsi.colostate.edu/suggest-a-topic/

Production

Food Production Level 1

Broccoli is a cool season vegetable and can be grown as a spring or fall crop. Seeds will germinate between 40-95°F but the optimal temperature for growth is 60-65°F, and it takes 75-140 days to grow to maturity. Broccoli is primarily planted in two ways, either by direct seeding or transplanting, with the majority of the industry using direct seeding. Seedlings that are transplanted can be started either in hotbeds or greenhouses. Broccoli is typically grown in double rows on raised beds. While it can grow in a wide range of soil types, for optimum growth the soil must be well-draining, moderately salt sensitive, nutrient dense, and have a pH between 6.0-6.5. Phosphorus and potassium may be added to the soil to meet nutrient demands. Irrigation is required to maximize yield, and is usually done with furrows and overhead sprinklers, though surface drip is also sometimes used. Weed control can be achieved with herbicides, mechanical control, and a good crop-rotation system. The most common broccoli pests include different types of caterpillars, which can be controlled using organic insecticides, synthetic insecticides, or by manually removing the worms (small crops only).

Looper Caterpillar
Looper Caterpillar, a common broccoli pest

Food Production Level II

The majority of broccoli is harvested from mid October through December, though crops can also be harvested through April. Broccoli is harvested for fresh consumption or processing, depending on many factors such as current market value. There is no way to mechanically harvest broccoli, so it must be harvested by hand. Fresh market broccoli is field packed. Good-quality broccoli should have dark or bright green, closed flower buds, and the head should be compact, with a cleanly cut stalk of the required length. The standard pack consists of heads that average 3 to 8 inches in diameter. Field workers either cut or snap the stems at 8 inches and place the heads on a harvest-aid belt. Two to four heads are bunched, secured with a rubber band, and then cut to a uniform 7 inches. Fourteen or eighteen bunches of broccoli are packed in a waxed-fiberboard carton that weighs a minimum of 23 pounds. Crown-cut broccoli consists of a top dome 5 to 5.5 inches in diameter, cut from the stem at 5 inches. A packed carton consists of 34 to 38 bulk- packed crowns and weighs a minimum of 20 pounds. Field-cut florets are loosely packed in tote bags and packed into cardboard cartons that weigh 9 to 18 pounds and contain three to four bags each. Broccoli destined for the freezer is also hand-harvested. The stem is cut at 6 inches, slightly shorter than for fresh market. The heads are placed on belts, then collected into large bins or trailers, and hauled to the processor.

Broccoli
Large bins of broccoli florets

Food Production Level III

Once harvested, broccoli must be cooled rapidly to preserve shelf life. Liquid icing of the field packed cartons is common. The optimal storage temperature is 32°F, varying outside of this temperature could negatively affect shelf life. Broccoli is extremely sensitive to exposure to ethylene, and exposure to as little as 2ppm of ethylene can reduce shelf life by 50%. Once broccoli is field packaged, the cartons are filled with slushed ice for shipping. Optimal storage life for broccoli is 21-28 days.

Food Safety

Broccoli can be consumed raw or cooked. Broccoli should be stored unwashed in the refrigerator until use, and for best quality, it should be used within four days after purchase. Broccoli should be washed before consumption, and standard safety practices should be followed to ensure food safety.

Consumption

Over the last 25 years, broccoli consumption has increased over 940%. The average annual per capita consumption of broccoli in the United States is 5.8 pounds.

Nutrition

Broccoli provides an excellent source of vitamin K, vitamin C, chromium, and folic acid. It is a good source of dietary fiber, pantothenic acid, vitamin B6, vitamin E, manganese, phosphorus, choline, vitamin B1, Beta-carotene, potassium, and copper. Broccoli in the diet also supplies vitamin B1, magnesium, omega-3 fatty acids, protein, zinc, calcium, iron, niacin, and selenium. One cup of broccoli contains 54 calories, 0.64 grams of fat, provides 135% of the daily vitamin C requirement, and 245% of daily vitamin K requirement of a 2000-calorie per day diet. Vitamin C, vitamin E, lutein, and other antioxidants in broccoli are anti-inflammatory and prevent damage to the body caused by free radicals. Phytonutrients are highly concentrated in broccoli, especially glucosinolates, which are under scientific investigation for their role in cancer prevention. Recent studies have provided evidence that glucosinolates decrease the metastatic potential of lung cancer, prolong survival in patients with bladder cancer, and lower the risk of breast cancer.

References

Authors

Sara Mullaney

Sara Mullaney

Maggie Weinroth

Maggie Weinroth