Do you want to learn a little bit about how to process seaweed?
Well come along and find out more!
Between 1981 and 1992 world production of seaweed increased from 3.2
million tons to 7 million tons. Brown algae production was at 5.2 million
tons (75%); red algae production was at 1.73 million tons (25%); and green
algae production was at 0.07 million tons (0.5%). Wow! That's a lot of
seaweed. If you read are harvesting page, you will realize that the world
has move from harvesting and processing seaweed by hand to using higher
One Example of Technology
J.R. Hulls developed such a process in 1976. He was assigned
to Bio-Kinetics Inc. his process involves producing an algae product and
purifying aqueous organic waste material to provide clean water. Starting
algae and aqueous waste are admixed in sufficient amount to provide
nutrients for the algae, which are grown in symbiotic relation ship with
aerobic bacteria present. The mixture is aerated with, if desired, carbon
dioxide added, and is exposed to alternate period of light (e.g., one-half
second to ten seconds) and darkness (about ten times as long as light
period) to accelerate growth of the algae, harvesting the algae product to
maintain the growth rate at a very high level.
Have you ever eaten sushi? Did you know that a lot of sushi uses
seaweed as one of its ingredients? The green crunchy wrapping sometimes
used in sushi is called nori. Nori is made from seaweed - but it is not
in a fresh state. After the seaweed Prophyra is picked, it is immediately
dried into sheets. This was formerly done by sun-drying process, but this
job is now highly mechanized. The harvesters only take what they can
process in one day. Nori is first washed with freshwater than fed into a
shredding machine, which makes it to a piece 0.5x1 cm in size. The cut
nori is then thoroughly mixed with freshwater, 4 kg of nori per 100
The nori/water mixture is than fed into a machine that is almost like
a papermaking machine. In the machine it is put on top a wooden frame
about 30 sq cm on the outside, which is fit into mats of split bamboo
20x18 cm big. Then it's placed into a wire netting screen about 600 ml of
mixture is fed into each frame and the water drains away through the mats
and screen. The frames then move slowly across a production line and
afterwards it goes over a heated surface. The nori and the bamboo mats
are then moved going back in a circle for more nori-water mixture.
After the nori sheets are piled up and put into an oven to reduce the
moisture content to about 18%. This is in order to make a good product.
The temperature of the drying process is 500C. Than the bamboo mats are
then removed, the nori is than put together it 10s and packed in bundles
The nori is then shipped to a co-operative shipping point. There
they are carefully packed and sealed in cellopane so that the moisture
uptake is reduced as much as possible. Then they are shipped to all parts
of the world. The Japanese output is about seven billion sheets a year.
Korea produces 60-100 million sheets.
North American Kelp
Asia is not the only place that harvests and process seaweed. Robert
Morse, a marine engineer who was one of the first members of Maine's
Organic Farmer and Gardeners Association, founded North American Kelp in
1971. North American Kelp is a Maine-based company with more than 28
years of experience in processing kelp. The company harvests several
types of kelp year-round with a regular crew of 10 that becomes 35 during
peak harvesting seasons. The kelp is processed in North American Kelp's
facility in Waldoboro, Maine. The company harvests sea kelp from the same
cold clean water that has been providing world-famous seafoods for
Yantai Prince Chemical Co. LTD
YSIC and a German Company started a joint venture named Yantai Prince
Chemical Co. LTD. Yantai Prince Chemical Co. LTD. was found in 1970 and
is one of the founders of seaweed processing industry in China. Yantai
Prince Chemical Co. LTD. annually produces 1,200 tons of sodium alginate,
500 tons of mannitol, 15 tons of iodine, 200 tons of carrageenan and 100
tons of agar-agar. Recently they have advance new productions such as
EPOXY RESIN a series of printing auxiliaries and various aquatic
foodstuff. Alginate, carrageen and mannitol have been exported to over 10
countries in the past 20 years. It is mainly marketed in Europe, America,
Japan, and Korea. Alginate is a thickener an emulsifier. Carrageen is
a suspending agent used in foods, medicine, cosmetics, and industrial
products. Mannitol is used in intravaneous medicine.
Danisco Ingredients and Carrageen Seaweed
Yantai Prince Chemical Co. LTD rented three machines to a
seaweed-processing factory in southern Chile. This client, Danisco
Ingredients, uses carrageen seaweed as a raw material. They produce
carrageenan, a food additive that is extracted from the seaweed. Danisco
purchases red, black and narrow leaf carrageen.
The harvesters use helmets and lead boots to harvest red narrow leaf
carrageen. The black narrow leaf washes up on the beaches, and women and
children picked up the black narrow leaf from the ocean's shore.
The three machines rented were the Vincent horizontal shredder with
narrow blades, a Vincent triple pass rotating drum dryer, and a soft
squeeze KP-6 press. The VS-35 shredder has worked well both on baled dry
material and on fresh seaweed from fishing boats. Initial plugging was
overcome by going to a discharge screen with 2-1/4 holes. The one
remaining problem has been blades damage arising from rocks to witch the
seaweed is attached.
The dryer has also worked very well. The seaweed goes through a
sticky stage as it is dried from 82% down to 18% moisture. However it has
not adhered to the inside of the dryer so the product recirculation
feature does not appear necessary. Most tests were run feeding two to
four pounds per minute into the dryer. Gas recirculation was not used in
order to keep down the wet bulb temperature. The highest temperature
material can reach in the dryer is the wet bulb temperature (dew point),
and it is felt that the viscosity of carrageenan produced might be
adversely affect by exposure of carrageen to high temperature. It is not
possible to remove any moisture at all from the seaweed with a screw
press. They tried shredding , macerating, and adding lime; nothing
However, the press worked well at removing free water from previously
dried seaweed that was later washed to remove sand and rocks. In one test
moisture content was reduced from 68% to 60%.
Algae Production Processes and Products
Successful algae production depends on matching the right kind of
water to the right kind of algae culture. Depending on the kind of algae
being cultured, fresh water, brackish water, salt water, industrial water,
sewage water, and even polluted water can be used. Sufficient amounts of
the right kind of water must be available. Of course, the more expensive
the water the more costly the production will be.
Most processing involving the deliberate production of algae were
developed beginning in the 1950s. We were surprised to learn that there
are many people that are inventing new ways to grow better algae. The
list is too long and the methods are too complicated to describe here. We
were disappointed because all the books we got on aquaculture are all old.
Products From Algae Culture
Some interesting products are created from various algae culture
processes. A process for extracting antibiotics from several types of
algae it was developed in 1968. A variety of processes are used to make
dyes from algae so that materials can be colored (known as pigmentation).
Green algae contain many of the valuable nutrients needed for human
consumption. Various processes have been developed to remove the
undesirable appearance taste and odor that come with the use of green
Research in the use of atomic energy has lead to the discovery of the
use of algae can help separate heavy isotopes of carbon from light isotope
Algae uses the process of photosynthesis in its growing. Process of
been developed to deliberately produce oxygen using algae culture. Even
General Electric Company has an apparatus of oxygen and algae production.
This process might one day solve the problem of providing a steady supply
of oxygen for use in space.
One of the most popular uses of algae is the production of thickening
agents and emulsifiers, which help to make food and household products
thick, smooth, and creamy. Algin and carageenin are the two main
thickening agents made from algae.