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Sugar beet

January 15, 2021
Sugar beet

The sugar beet, whose scientific name is Beta vulgaris subsp. vulgaris var. altissima , refers to a type of beet that is commercially grown for sugar production due to its high concentration of sucrose. After sugar cane, this tuber is the second largest source of sugar in the world . It belongs to the Amaranthaceae family of plants1 , hence it is a close relative of amaranth and quinoa.

Characteristics and data of interest

  • Like the common beet , the sugar variety has a fleshy root, but white in color and a more elongated shape.
  • Each plant develops the root or tuber underground, while exhibiting a rosette of bright green leaves on the surface; it can reach a height of approximately 35 cm.
  • The sucrose from sugar beet is formed in the sheets during the photosynthesis process, and then goes to the roots for storage.
  • Each root is said to contain 75% water, approximately 20% sugar, and 5% pulp. The exact sucrose content can vary from 12 to 21%, depending on the growing conditions. The pulp, insoluble in water and composed mainly of cellulose, hemicellulose, lignin and pectin, is often used for animal feed.
  • When fully grown, the average weight of a sugar beet ranges from 0.5 to 1 kg.2
  • There are different varieties of sugar beet; some of the most common are Daphna, Senada, Degas, Samantha, Khazar, Dyna, Marisma and Sherif, among others.
  • Unlike sugar cane, which grows exclusively in tropical and subtropical areas, sugar beet grows in temperate climates.

Origin and history of sugar beet

Sugar beet was grown as a vegetable and animal feed long before it was valued for its sucrose content. The first beet sugar was produced experimentally in 1747, by the German chemist Andreas Marggraf. Years later, the first beet sugar factory was built in Silesia (present-day Poland).

In 1811 Napoleon became interested in the beet sugar manufacturing process, as the British blockade had cut off the supply of cane sugar from the West Indies to France. This situation resulted in the establishment of 40 beet sugar factories on French territory. During the 9th century the production of beet sugar increased rapidly throughout Europe; By 1880, its tonnage had exceeded the production of cane sugar.

At present, beet sugar accounts for almost all of the European Union’s sugar production and about a fifth (20%) of total world production. Russia, France, USA, Germany and Turkey are among the largest producers of sugar beet in the world3 . Several countries in Central and South America, such as Chile, Mexico, Brazil and Argentina, have also successfully ventured into the cultivation and processing of this variety.

How is the cultivation of sugar beets?

Sugar beets have been cultivated for centuries as a summer crop, especially in the cold and temperate regions of the planet; however, it is currently also grown as a winter crop in warmer areas, including parts of South America, Africa, the Middle East, and southern Europe.

For its industrial cultivation , precision drills are used that sow the seeds 2-4 cm deep, leaving a space of 6-8 cm between them and 50-56 cm between one row and another. Simultaneously with the sowing of the seeds a fertilizer is applied; these are then covered and a herbicide is applied by spraying. The duration of the cultivation can vary depending on the region, but the minimum waiting time is 3-4 months. When the time comes, the sugar beet harvest is done mechanically.

Both for industrialized planting and garden planting , these are the main aspects to take into account about its cultivation4 5:

  • It is grown from seed.
  • It can be sown in sandy or clay soils , but the most important requirement is that the soil must be rich in nutrients and capable of retaining some moisture. The land must be level and have good drainage.
  • It is always recommended to prepare the soil before planting. The deep plowing is the best way to ensure that the roots penetrate the soil and extract as much moisture and nutrients.
  • The ideal temperature range for the growing months is between 15 and 21 ° C.
  • Seed germination occurs approximately 10 days after sowing. The growing period, from sowing to harvest, typically ranges from 170 to 200 days.
  • Regular and moderate watering is required to get the average crop ( varies with weather conditions ).
  • Strong winds are damaging to the sugar beet plant as they often create a crust of soil that prevents the young beets from leaving the ground.
  • Beets are susceptible to many diseases and insect pests , for example the fungal disease known as black rot, characterized by the presence of lesions on the stem near the soil surface. Another common disease is Cercospora leaf spot, which causes yellowing of the leaves and a reduction in the size and sugar content of beets. Precautions against worms, beetles, and nematodes should also be taken.
  • In most regions, sugar beets are grown in spring-summer for harvest in the fall; Harvesting generally begins in late September or early October (before low temperatures cool the soil).
  • For collection, the soil around the plant must be loosened, slightly turned to the sides, holding the rosette of leaves with the hands and finally, gently pulled to extract the entire plant from the ground.
  • A ripe sugar beet root can grow up to 1 to 2 kg , and it can contain 8 to 22% sucrose.

How is the manufacturing process of beet sugar?

Generally, the beets are transported to the factory right after harvest. There, a sample is examined to determine the average size of the roots and its sucrose content. This is followed by a series of steps to turn these tubers into the sweet, refined sugar we see in supermarkets.

  1. After examining the sample, the beets go through a washing process to remove all dirt; They are mechanically cut into thin strips and passed to a machine called a diffuser (container), which is responsible for extracting the sugar content into a hot water solution. Inside the diffuser, the beet strips go in one direction, while the hot water flows in the opposite direction. In this way the first by-product is obtained, known as “raw juice”.
  2. The strips, or beet pulp, come out of the diffuser with a high percentage of humidity (95%), but with a low content of sucrose. Next, the wet pulp is pressed with the help of presses to extract up to 75% of its moisture; thus the remaining sucrose is obtained and the energy required to dry said pulp is reduced ( the pressed pulp is dried and sold as animal feed ).
  3. Then, the liquid extracted from the pulp is combined with the raw juice that was initially obtained. This juice is subjected to a carbonation process to remove all impurities. It is first mixed with a solution of calcium hydroxide in water, which precipitates impurities, including sulfates, phosphates, citrates, and oxalates. Carbon dioxide is then bubbled through the alkaline sugar solution, precipitating the lime as calcium carbonate; chalk particles trap some impurities and absorb others.
  4. Then everything goes through a filtering process , obtaining a light brown sugary solution, called thin juice. The thin juice is converted into a thick juice through evaporation. The result is a concentrate (60% sucrose), similar in appearance to traditional pancake syrup.
  5. Then, the thick juice goes through a crystallization process , from which a mixture of sugar and syrup is obtained, known as cooked mass. The cooked dough goes to a centrifuge, where the syrup is removed and the remaining sugar crystals are washed. The centrifuge rotates at a higher speed to partially dry the crystals, which will then be transported to a rotating granulator.
  6. The crystals are granulated, dried with hot air and finally, after a long process, the beet sugar is obtained.

Photos of sugar beet

How are cane sugar and beet sugar different?

The white table sugar that we see in supermarkets can come from sugar cane or sugar beets. Sellers often do not clearly specify the plant source of the product and this leaves many wondering how they can differentiate cane sugar from beet sugar .

Chemically speaking, the two products are identical. Refined sugar is pure, crystallized sucrose, just like salt is simply sodium chloride. Although sucrose is also found naturally in honey, dates, and maple sap, it is more concentrated in sugar cane and sugar beets, hence these are the two main sources of sugar on the market. However, the refining process renders the original source irrelevant, since sucrose is completely extracted from the plant.

Actually, the main difference between the two products lies in the way they are processed. For example, to make pure white sugarcane crystals, many factories use charred bone ( porous black material made by charring animal bones ), whereas beet sugar does not require this step.6 7

Note : Although the final sugarcane product does not contain bone, this distinction is important to many vegans and vegetarians who want to minimize animal suffering.

Despite their great similarity and although the industry maintains that they are identical products, many chefs, bakers and pastry chefs claim that cane sugar and beet sugar do have differences . In fact, many of them claim that they only use the first one because it seems that beet sugar negatively affects the taste of their products. Some claim that this difference is due to the trace minerals in both plants, although it is also likely due to changes in humidity that affect baked goods and desserts.

References:

  1. https://es.wikipedia.org/wiki/Amaranthaceae
  2. https://americansugarbeet.org/who-we-are/what-is-a-sugarbeet/
  3. http://www.fao.org/home/es/
  4. http://www.fao.org/land-water/databases-and-software/crop-information/sugarbeet/en/
  5. https://hort.purdue.edu/newcrop/afcm/sugarbeet.html
  6. https://www.britannica.com/story/whats-the-difference-between-cane-sugar-and-beet-sugar
  7. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/bone-char
Louise Hammond
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My name is Louise Hammond, and I am the creator of this website, a place to find information about tubers, bulbs and medicinal roots. In Dreamsship.com I show the properties, benefits, characteristics, photos and images, ways of growing and how to make delicious meals from starchy vegetables.