Cultivation of Chondrus crispus in Denmark - Tangbogtangbog.dk/wp-content/uploads/bruhn-2.pdf ·...

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NATIONAL ENVIRONMENTAL RESEARCH

INSTITUTE

AARHUS UNIVERSITY Seaweed Symposium

Cultivation of Chondrus crispus in Denmark

- production potential, quality and food safety

Annette Bruhn1, Michael Bo Rasmussen1, Martin Mørk Larsen1, Birgit Olesen2, Carlos Arias2, Thomas Worm3

1 National Environmental Research Institute, Aarhus University

2 Biological Institute, Aarhus University

3 CP Kelco A/S


INSTITUTE

AARHUS UNIVERSITY Annette Bruhn 26.08.2010Cultivation of Chondrus crispus in Denmark

Chondrus crispus – Irish/carrageen moss

Carraigín = ”small rock” (Gaelic)

Photo: www.cybercolloids.net

150.000 T / year

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Carrageenan (E407)

Price: up to 200 USD per kgPhoto: www.eurogum.dk


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Carrageenan – alternative ressources

Cold water species = 15 % Warm water species = 85 %

Gigartina

Chondrus

Euchema

Kappaphycus

Euchema

Kappaphycus

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Carrageenan (E407)


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Chondrus - harvest

Nova Scotia

Ireland

Spain

DK?

Photo: www.greatdreams.com & www.fao.org

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� How much can we produce?

� How do we optimise growth and production?

� How do we optimise yield and quality of carrageenan?

� Can we sell it?

� Does it pay?

Cultivation of Chondrus in Denmark?


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� Landbased tanks at Dansk SkaldyrCenter, Nykøbing Mors

� Cultivation in open sea

� Laboratory experiments

Experiments

Photo: Michael Bo Rasmussen, DMU

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� 12 tanks (0.6 m3 )

�water exchange 6 times per day

� air

� nutrients ca. 20 µM N and 4 µM P

� 2/4/6/8/12/16 kg per m2.

� Weekly harvest/adjustment

Landbased tumblecultures


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Landbased cultivation� Growth rates up to 4% d-1

[1, 2]

[1]. Bidwell et al, 1985 [2]. Bruhn et al, 2008

0

100

200

300

400

500

22-04-2008 01-06-2008 11-07-2008 20-08-2008

Date (2008)

Photo

n flu

x d

ensity

(mol photo

ns d

-1 m

-2)

-6

-4

-2

0

2

4

6

Rela

tive g

row

th rate

(%

d-1)

Photon flux density

Relative growth rate

� 30 T seaweed (DW) year-1 ha-1

� 14 T carrageenan year-1 ha-1

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Landbased cultivation� Optimal stocking density: 4-6 kg m-2

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20

40

60

80

100

2 4 6 8

Stocking density (kg WW m-2

)

Car

rag

een

an y

ield

(%

DW

and

g m

-2 w

eek

-1)

% DW

g m-2 week-1

[2]. Bruhn et al, 2008


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� Quality� high yield: 47 % (23%)

� good quality: CAM-value: 176 (140)

� clean raw material – semirefined carrageenan

Landbased cultivation

0

50

100

150

200

Udbytte % CAM-værdi

Danmark

Nova Scotia

Denmark

Nova Scotia

Yield (% of DW) CAM value[2]. Bruhn et al, 2008

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� Economy� Income: 1.2 mio DKR year-1 ha-1

� Costs: 8.5 mio DKR year-1 ha-1

� Costs (theoretical) [1]: 0.9 mio DKR year-1 ha-1

Landbased cultivation

[1]. Bidwell et al, 1985


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Cultivation in open sea

� Neutral to negative growth rates

� epiphytes!

� Mexico up to 2,4% [3]

� Carrageenan yield and quality

as in landbased cultivation

� July and August

� 2 * 2 locations +/- exposure

� Limfjorden : Salling / Lysen

� Kattegat : Anholt / Grenå

[3] Zertuche-Gonzalez et al. 2001Photo: Michael Bo Rasmussen, DMU

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Laboratory experiments

�Impact of light and nitrogen

� 30 tanks of 3 litres

� 2 light intensities

(35, 120 µE)

� 5 N concentrations

(5,20,50,100,200 µM N)

Photo: Michael Bo Rasmussen, DMU


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� High light doubled growth rates and had positive effect onCAM value

CA

M v

alu

e

N concentration in media (µM)

High light (120 µE)

Low light (35 µE)


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Laboratory experiments� Carrageenan yield increases with N-limitation (Neish effect)[4]

R2 = 0,5032

30

35

40

45

50

55

60

65

70

5 7 9 11 13 15

C:N forhold

Carr

ageenan u

dbytte (

%)

C:N ratio in tissue

Carr

agee

nan

yie

ld(%

of

DW

)

[2]. Bruhn et al, 2008. [4] Neish et al, 1977,


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� N: trade-off between carrageenan quality and yield

160

165

170

175

180

185

190

40 45 50 55 60 65 70

Udbytte (%)

CA

M v

ærd

i

N 50 eller derover

N under 50

Carrageenan yield (% of DW)

CA

M-v

alu

e N≥50 µM

N< 50 µM


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Food safety� Limit values – refined carrageenan

� Pb (Lead) 5 ppm

� Cd (Cadmium) 2 ppm

� Hg (Mercury) 1 ppm

� As (Arsenic) 3 ppm (EU) / 2 ppm (USA)


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Arsenic

� Toxic element� Inorganic form most toxic

� Concentrates in algae [5]

� Highest concentrations in young tissue

� Inorganic form approx 4% of total arsenic in Chondrus [6]

� Limit values exceeded in refined carrageenan from

Danish produced Chondrus

� EU = 3 ppm

� USA = 2 ppm

[5] Neff, 1997 [6] Almela et al, 2006

0

1

2

3

4

5

Rønbjerg Nykøbing

Mors

Nova Scotia Gennemsnit

DMU-lab

Gennemsnit

CP Kelco

To

tal

Ars

en (

pp

m)

EUUSA

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Arsenic

Striped columns indicate Mastocarpus sp.*

0

2

4

6

8

10

12

14

16

Rønb

jerg

Nyk

øbing

Mor

s

Elseg

årde

Egå M

arina

Gre

nå, K

C

Gre

nå Kalkg

r.

Frede

riksh

avn

Hirt

shals

Hans

tholm

Kolding

Fjord

Vejle fj

ord

Hors

ens Fjo

rd

Færø

erne

Ars

en

koncentr

atio

n (

ppm

) Målt hos CP Kelco

Målt på DMU i Roskilde

CP Kelco lab

DMU lab

To

tal A

rsen

ic(p

pm

)

Faroe

Isla

nds

*

[6] [7]

[6] Almela et al, 2006. [7] Thomson et al, 2007


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Conclusions

� High yield

� Good quality carrageenan

� Too energy expensive

� Too high concentration of arsenic

+

÷

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� How much can we produce?

� How do we optimise growth and

production?

� How do we optimise yield and

quality of carrageenan?

� Can we sell it?

� Does it pay?

Cultivation of Chondrus in Denmark?30 T DW year-1 ha-1

6 kg m-2. 20+ µM N.

20-50 µM N. High light

Not at present

Not at present


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Future challenges?

� Arsene� differentiation of limit values: organic / inorganic arsenic

� harvest method – harvest of oldest tissue

� Economy� landbasede tanks – less energy – paused aeration

� cultivation in open sea

� harvest method – harvest of oldest tissue?

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AARHUS UNIVERSITY Seaweed Symposium

Thanks to

Ditte Tørring, Finn Bak,

Kitte Gerlich Linding, Tanja

Quortrup, Egon Frandsen, Carsten

Fomsgaard, BIODYK, Miljøcenter

Ringkøbing & the Faculty of

Agricultural Science, Aarhus

University.

The project was supported by the

European Fisheries Sector Program

(FIUF) and the Danish Food Industry

Agency (DFFE), Ministry of Food,

Agriculture and Fisheries.

Photo: Jan Krog


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Chondrus - arsenicChondrus

from 11 locations

Mastocarpus

from 2 locations

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Air dried Chondrus

0

20

40

60

80

100

16.06 22.06 29.06 3.07

Date

Ca

rra

geen

an

yie

ld (

% o

f D

W)

/wa

ter c

on

ten

t

(%)

190

195

200

205

210

215

220

225

230

235

CA

M v

alu

e

Carrageenan yield (% of DW)

Water content (%)

CAM value

Cultivation of Chondrus crispus in Denmark - Tangbogtangbog.dk/wp-content/uploads/bruhn-2.pdf ·...

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