Sugar beet is
an annual plant
in the family Amaranthaceae,
the tuberous root of which contains a high proportion of sucrose.
It is cultivated in temperate regions with adequate rainfall and
requires a fertile soil. The crop is harvested mechanically in the
autumn and the crown of leaves and excess soil removed. The roots
do not deteriorate rapidly and may be left in a clamp in the field
for some weeks before being transported to the processing plant.
Here the crop is washed and sliced and the sugar extracted by
diffusion. Milk of lime is
added to the raw juice and carbonatated in
a number of stages in order to purify it. Water is evaporated by
boiling the syrup under a vacuum. The syrup is then cooled and
seeded with sugar crystals. The white sugar which crystallizes out
can be separated in a centrifuge and dried. It requires no further