Monday, 21 April 2014 18:30

Where Does Sugar Come From? Part 2: Sugar Beets

 Did you know about 50% of U.S. sugar consumption is derived from sugar beets?

  • Latin Name:

    Beta vulgaris 

     

     

  • Growth:

    What are sugar beets?  How do sugar beets grow?

    The sugar beet is a white conical root with a flat crown and a rosette of leaves. Sugar is formed through photosynthesis in the leaves that is then stored as sugar in the root which contains 12 to 21% sugar, 75%water and 5% pulp depending on the growing conditions and the cultivar. Pulp and molasses are byproducts of the beet crop and add 10% to the value of the harvest.

    The average weight of a sugar beet ranges from 1 lb. to over 2 lbs. The foliage is a bright rich green color and grows over 14 inches tall. Sugar beets grow best in temperate zones where they are planted in spring and harvested in the fall. In warmer areas where there are no freezing temperatures, they are planted in the fall and harvested in spring.

  • Propagation:

    How are sugar beets propagated?

     

    Before planting, fields are deeply ploughed as the beets grow better in loose soil.  Then seeds are planted into the rows and thinned, so they are spaced about a foot apart.  Sugar beets reach maturity 90 to 95 days after planting.

  • Harvest:

    How are sugar beets harvested?

     

    Sugar beets mature 90 to 95 days after planting.  They are harvested when the leaves turn yellow as the plant pushes all its nutrients into the beet root for winter storage.  This is when the sugar content in the beets is at its highest, so this is the best time to harvest.   The beets are harvested by a mechanical harvester with a load truck following alongside to catch the beets and then transported to a processing plant.

     

     

  • History:

    What is the history of sugar beets?

     

    Olivier de Serres first extracted sugar from beets in the 16th century when he discovered that boiling them yielded a juice similar to that made from sugar cane (except it was red in color at the time).  In 1747, Professor Marggraf discovered that the sugar in beets had the same properties as that of sugar cane.  However it wasn’t until 1801 that the first beet factory was opened  in Silesia.  Napoleon compelled farmers to begin devoting large acreages to growing sugar beets and prohibited the importation of sugar from the Caribbean.  Sugar beet production started in the United States around 1890 and in the mid-1920’s in the United Kingdom.

  • Top Producers:

    Who are the top producers of sugar beets?

    France, the United States, Germany, Russia and Ukraine are the biggest producers of sugar derived from sugar beets.

  • Varieties:

    Which is better:  Beet or Cane sugar?

    • Some people taste no difference between cane sugar and beet sugar unless they are tasted side by side.
    • For baking, always use cane sugar, especially when using brown sugar. Brown beet sugar is actually white beet sugar with sugarcane molasses mixed back in for taste, texture and color.
    • If you suspect you might have an allergy to sugar from one source, try using the other. It may make a big difference.
  • Products:

    How are sugar beets processed?


    1. The beet roots are washed, mechanically sliced into strips, or “cossettes”, and passed through diffusers to extract sugar content into a water solution. In the diffusers, the water and cossettes go in opposite directions which more efficiently draws the sugar out of the cossettes.

    2. This sugar water is called “raw juice.” The cossettes, pulp now, are then pressed to extract even more sucrose out of them and then sold as animal feed. The sucrose is added back to the raw juice.

    3. Bacterial breakdown of the sucrose is into undesirable sugars and acids is sometimes chemically arrested by adding formaldehyde to the mixture and carefully monitoring pH levels.

    4. Carbonation: The raw juice is mixed with a solution of lime (calcium hydroxide in water) and carbon dioxide is bubbled through it in order to entrap and absorb impurities and to chemically stabilize the mixture. The heavier particles settle out in the tanks. This process may be repeated in order to further purify the raw juice. This cleaner light brown solution is called “thin juice.”

    5. Evaporation: The thin juice is concentrated by means of evaporation to make a thick syrup which is then crystallized or can be stored for later use.

    6. Crystallization:
    The thick juice is fed to the crystallizers, recycled sugar is dissolved into it and the resulting syrup is called "mother liquor".
    This is concentrated further by boiling under vacuum in large vessels and seeded with fine sugar crystals. These crystals grow, as sugar from the mother liquor forms around them.


    The resulting sugar crystal and syrup mix is called massecuite (which means "cooked mass" in French).
    The massecuite is passed to a centrifuge where the liquid is removed from the sugar crystals.
    Remaining syrup is rinsed off with water and the crystals dried in a granulator using warm air. The recycled syrup is fed into another crystallizer from which a second batch of sugar is produced.
    This sugar ("raw") is of lower quality with a lot of color and impurities and is the main source of the sugar that is re-dissolved into the mother liquor.


    The syrup from the raw sugar is also sent to a crystalliser. From this a very low quality sugar crystal is produced (known in some systems as "AP sugar") that is also redissolved.
    The syrup that is separated is also called molasses; still containing sugar but with too many impurities to be economically processed further. Only molasses from sugarcane is consumable.

  • Top Health Benefits:

    What are the health benefits of sugar?  

    What is the impact of sugar on health?

    Sugar intake should be severely limited as its impact on health can be, and often is, very bad. Too much sugar contributes to increased rates of obesity, diabetes, inflammation and dental problems.

    The only good reasons for eating sugar are 1) to sweeten foods that are nutritious but otherwise unpalatable; and 2) for an extra burst of quick energy - especially for athletes just before they compete.

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