Red seaweeds are rich in phycocolloids,
which make them excellent for use as stabilising and gelling agents in a number of
industries.
Together with microscopic algae called
phytoplankton, seaweeds (also known as
marine macroscopic algae or marine ‘sea
vegetables’) are responsible for all primary
production in the oceans and, therefore,
form the base of the food chain in the
oceans.
Seaweeds are amongst the fastest growing
organisms on the planet. For example, under optimal conditions, the giant kelp Macrocystis pyrifera, can grow nearly a meter
(three foot) a day, attaining lengths in excess of 50 m.
While most seaweeds are soft and fleshy, a
large number of particularly red seaweeds
are hard as rock. These hard red seaweeds,
commonly known as coralline algae, deposit lime into their cell walls.
Strictly speaking, not all seaweeds are
plants. Only the green (ancestors to the
land plants) and red seaweeds are currently
considered plants. However, like plants,
most microscopic algae and seaweeds depend on sunlight to produce food through
photosynthesis.
Many marine scientists are of the opinion
that red seaweeds should not be treated as
‘plants’ but placed in a kingdom all on their
own, sister to the plants. The reason for
this suggestion is that they are the only
group of organisms on the planet that pos-
The red seaweeds account for more than
half of all the currently known species of
seaweeds.
sess three life cycle stages.
Seaweeds assimilate minerals directly from
the sea and are thought to be the single
most nutritious foods that you can eat.
Rich in trace elements and vitamins, many
of them frequently contain more protein
than meat and more calcium than milk.
The word seaweed is so commonly used,
yet to refer to these marine macroscopic
algae as ‘weeds’ is so very far from the
truth. Although we often cannot smell or
taste them, many ingredients in our foods
and household products come from the sea
and from seaweeds.
Common uses of seaweeds
Green seaweeds
Eaten in the Far East as a green vegetable
in salads and soups.
Are rich in carotenoids (an antioxidant, age
-defying substances).
Are now known to help in preventing cancer (including breast cancer in woman),
heart disease, and strokes.
Beta carotene derived from green seaweeds, is used as a yellow-orange food colorant in cheese, coffee creamers, egg substitute, margarine, mayonnaise, multivitamins and salad dressings.
Whole brown seaweeds and kelp