Bi9540 Biotechnology and practical use
of algae and fungi
Lecture 6 – Algae in food industry
History of algae as food source
 Ancient records show that algae were consumed also by
populations of cavemen
 500 BC macroalgae were collected in China
 14th century report Aztecs harvesting Arthrospira using it
for preparation of tecuitlatl
 Harvesting of Arthrospira in Chad dates back to Kanem
Empire (9th century AD)
Traditional food
 Algae were traditionally consumed worldwide, however,
during modern age the consumption vanished
 Strong tradition is in Asian countries (Japan, China, Korea,
Philipines,…), Chad, Mexico
 Once traditional consuments, Ireland is now renewing
interest in algae
Global market
 42 countries currently report commercial macroalgae
activity
 China is the top producent of algae (Laminaria as prime)
 North Korea, South Korea, Japan, Philippines, Chile,
Norway, Indonesia, USA, India – 10 countries contribute
about 95 % to the global macroalgae market
 About 90 % of production is culture-based
 Asia covers 99 % of production (China 75 %)
Global market
 Porphyra, Kappaphycus, Undaria, Euchema, Gracilaria and
Laminaria make up 99 % of produced macroalgae
 World’s total harvest increased from 3 million tons in 1981
to 13 million tons in 2002 (according to FAO)
 Porphyra is the most valuable macroalgae
Ge-Xian-Mi
 Nostoc sphaeroides
 Regional use as food or ingredient
 Traditionally in China where it can be found in rice fields
 Colonies can reach 2.5 cm in diameter
 Dried Nostoc can be sautéed with oysters, used in soups
or as thickener for food
Nostoc flagelliforme
 also known as faat choy, fa cai, black moss, hair moss or hair weed
 Chinese delicacy for about 2000 years
 Appreciated for herbal values and spiritual image
Arthrospira
 Filamentous cyanobacterium
 Also called Spirulina
 Favorite in Mexico and Chad
 In 1940 Dangeard reported on dihé consumed in Chad and
suggested it was Arthrospira
 Dihé is an important source of vitamin A
Arthrospira
 Aztecs collected and consumed Arthrospira
 Tecuitlatl (stone excrement) was consumed to
boost energy. The food was some kind of dry
cake
 Collected in Chad
 Consumed with maize, …
Porphyra sp.
 Popularly known as Nori (Japan, Gim (Korea) or Zacai (China)
 One of the most nutritious macroalgae
 Protein content 25-50 % (75 % digestible)
 Source of trace elements and vitamins
 Excellent source of iodine
 Low in sugars (only 0.1 %)
 Taste of nori caused by content of
alanine, glycine and glutamic acid
Porphyra
 First cultivations in Japan and Korea date back to 17th cent.
 Common names are found in 16 languages, which proves
widespread usage of the alga
 Nearly 133 species are known (28 from Japan)
 In Japan, the annual production of Porphyra species is
valued at 100 billion yen (USD 1.5 billion)
 Sushi (Japan), Gimbap (Korea) are most important foods
using nori
Laminaria
 One of the biggest algae
 Native to Japan and Korea (cultivation since 1730)
 Millions of tons of kombu produced annually
 10 % proteins, 2 % fat
 Source of minerals
 Served with salmon
Undaria
 Second most valuable edible macroalga
 Millions of tons of wakame produced annually
 Processed as variety of food products
 Salted wakame
 Haiboshi wakame
 Cut wakame
 16.3 g protein / 100 g
Ulva
 Known as Sea lettuce
 Abundant around British Isles, China, Japan
 Ulva lactuca consumed in Scotland in soups and sallads
 Ulvas consumed by manatees 
 High in protein and minerals
 Rotting algae expel hydrogen sulfide
Chlorella
 Unicellular nonmotile green algae
 Although it is the most promising taxon concerning health
issues, the production doesn’t reach Arthrospira and others
 Widely used for processing of human dietary supplements
and animal feed
 Rich in protein, PUFAs, and minerals
 Study from 2002 suggesting endotoxin presence in
Chlorella was never proved
 Favorite for detoxification of organism
Interkosmos program
 Chlorella was tested in
microgravity conditions by
soviet space program
Algal extracts
Polysacharides
 Agar, alginate, carragenan
Agar
 D- and L-galactopyranose
 Name derived from Malaysian word ‘agar-agar,’ which
literally means ‘macroalgae’.
 As gelling agent katen it is know from Japan sice 17th cent.
 Most importantly is agar used as solidifier for media in
microbiology
 Non-ionic purified fraction is known as agarose
Agar
 High-grade (bacteriological) agar is extracted from
Pterocladia and Gelidium
 Spain, France, Portugal, Morocco, California, Mexico, New Zealand, South
Korea, India, Chile, Japan, …
 Food-grade is extracted from Pterocladia
 Low grade agars can be isolated from Gracilaria and
Hypnea
 Agar production is valued at approx. $200 million annually
Alginate
 Constituents of Phaeophyceae cell wall
 Mannuronic and guluronic acid
 Composition of heteropolysacharide blocks depends on
species and extraction procedure
 Most suitable for alginate extraction are brown algae
(Laminariales and Fucales) grown in cold water (<20°C)
 Approx. 50,000 tons are produced annually
 Scotland, Norway, China, USA
 Production is valued approx. USD 215 mil annually
Alginate
 Alginates have variety of applications
 Thickening of food (E401) – sodium alginate
 Stabilizers of ice cream
 Bandager, fabrics
 Thickening paste for printing
Carrageenan
 D-galactopyranose units
 Carrageenan is colloquial Irish word for macroalgae
 Known from Ireland since 1810
 Chondrus crispus used to be sole source, nowadays
Euchema, Ahnfeltia and Gigartina are also exploited
 30,000 tons of carrageenan produced annually
 As of 2011, global sales of carrageenan were estimated at
$640 million
Carrageenan
 Most raw material now comes from the Phillipines
 There are three main commercial classes of carrageenan:
 Kappa forms strong, rigid gels in the presence of potassium ions; it reacts
with dairy proteins. It is sourced mainly from Kappaphycus alvarezii
 Iota forms soft gels in the presence of calcium ions. It is produced mainly
from Eucheuma denticulatum
 Lambda does not gel, and is used to thicken dairy products.
Algal nutritional values
Kombu and Wakame nutritional values
Dietary supplements, pharmaceuticals
 Supplements rich in natural active compounds
 Healthy nutrition, immunomodulation, etc.
 Studies have proven positive effects on human health
Biologically active compounds
 Mostly microalgae, but also macroalgae are used as source
of biologically active compounds with variety of activities:
 Antibacterial
 Antiviral
 Antifungal
 Antioxidative
 Antiinflamatory
 Antitumor
 …
Bioactive peptides from algae
 Small peptides (2-20 AA)
 Variety of activities on cells and organisms
Anticancer peptides
Antihypertensive biopeptides
Antiatherosclerotic peptides
Immunomodulatory biopeptides
Other areas of algae
biotechnological
applications
Livestock feed
 Feeding of algae (mainly Chlorella) to cattle or pigs leads
to better growth and improved meat quality
 Even small addition has positive effect
Aquacultures
 Enhancement and improvement of fish production