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BAHAN INDUSTRI HASIL
PERTANIAN
PROF. SIMON BW Ph.D.
KARAGENAN
Carrageenan
• is obtained by extraction with water or
alkaline water of certain species of the class
Rhodophyceae (red seaweed)
CHONDRUS CRISPUS : ganggang merah
Sea weed for carrageenan
manufacture
CARRAGEENAN PRODUCTION
CARRAGEENAN MANUFACTURE
• Pengolahan karagenan masih jarang dilakukan.
Padahal prosesnya hampir sama dengan pengolahan
agar-agar. Kalau pada waktu ekstrasi untuk
mendapatkan agar-agar memakai asam, maka untuk
mendapatkan karagenan memakai basa. Bila
penanganan pascapanen telah sempurna, proses
selanjutnya dapat dilakukan secara sederhana untuk
skala rumah tangga dan dapat juga dilakukan untuk
skala industri.
Produksi Karaginan untuk Skala Rumah Tangga
1. Rumput laut direndam dalam air tawar selama 12 – 24 jam, kemudian dibilas dan
ditiriskan.
2. Setelah bersih rumput laut direbus dalam air dengan perbandingan rumput laut
dengan air sebesar 1 : 15, suhu 120 C selama 15 menit. Perebusan memakai
pressure cooker, selanjutnya dilakukan perebusan lagi tanpa tekanan pada suhu 10
C selama 2 – 3 jam.
3. Rumput laut yang lunak dihancurkan dengan blender dan ditambahkan air panas
(90 C). Perbandingan 1 : 30. Hasilnya disaring dengan kain kasa halus.
4. Filtrat diendapkan menambahkan metil alkohol dengan perbandingan 2,5 : 1, bisa
juga dengan menambahkan alkohol 90 % atau membekukannya pada suhu -10 C- 6
C selama 24 – 48 jam.
5. Endapan yang bercampur alkohol disaring dngan kain kasa. Hasil saringan masih
berupa keraginan basah. Filtrat yang beku perlu dicairkan dahulu untuk
selanjutnya disaring lagi.
6. Karagenan basah dikeringkan selama 3 – 4 hari. Tepung karagenan dapat diperoleh
setelah proses penggilingan.
Produksi Karagenan Untuk Skala Industri
1. Rumput laut dicuci dengan air tawar kemudian dikeringkan sampai kadar air
menjadi 15 – 25 %.
2. Rumput laut kering diesktraksi dengan ditambah air panas dan kalsium
hidroksida atau natrium hidrosida. Selama ekstraksi terjadi penghancuran
dan hasilnya berupa pasta. Penghancuran ini bertujuan untuk memperluas
permukaan rumput laut sehingga proses pelarutan karaginan akan lebih
mudah.
3. Pasta selanjutnya dimasukkan ke tangki atau bejana dan dipanaskan
selama 24 jam pada suhu 90 – 95 C.
4. Setelah itu pindahkan ke tangki lain atau bejana dan dipanaskan selama 24
jam pada suhu 90 – 95 C.
5. Setelah mendidih disaring dengan filter aid atau tanah diatomea. Hasilnya
disaring lagi dengan filter press.
6. Filtrate yang dihasilkan dipompa ke dalam tangki yang berisi propil alkohol
dan akan didapatkan serat karaginan.
7. Serat karaginan dipress, kemudian dicuci dengan alkohol segar dan dipress
lagi.
Standar Mutu
• Indonesia belum mempunyai standar mutu
karaginan. Standar mutu yang dikenal adalah
EEC Stabilizer Directive dan FAO/WHO
Specification. Tepung karaginan mempunyai
standar 99 % lolos saringan 60 mesh, tepung
yang terendap alcohol 0,7 dan kadar air 15 %
pada RH 50 dan 25 % pada RH 70.
CHEMICAL STRUCTURE
Struktur Carrageenan
Kappa carrageenan
Iota carrageenan
Lambda carrageenan
Powder characteristics and Storage Stability
• Carrageenan is sold as a powder. The color ranges from white to
brownish depending on raw material and process used. A typical
mesh specification is 99% through a 60 mesh (0.25 mm) sieve.
• A typical powder density of an alcohol precipitated carrageenan is
0.7. A typical equilibrium water content of an alcohol precipitated
carrageenan is 15% at 50% r.h. 25% at 70% r.h.
• Carrageenan is insoluble in organic solvents such as alcohol, ether,
and oil.
• Solubility in water depends on the structure of the particular
carrageenan, the medium, and the temperature.
• Generally the gelling carrageenans must be heated to dissolve
whereas non-gelling carrageenans may be dissolved in cold water.
Solubility
•
•
•
Carrageenan exhibits the solubility characteristics normally shown by hydrophilic
colloids. It is water soluble and insoluble in most organic solvents. Water miscible
alcohols and ketones, while themselves non-solvents for carrageenan, are
tolerated in admixture with carrageenan solutions at levels up to 40%. More highly
polar solvents, such as formamide and N,N-dimethylformamide, are tolerated in
still higher proportion and alone cause a marked swelling of the polymer.
The solubility characteristics of carrageenan in water are influenced by a number
of factors most important of which are:
a. the type of carrageenan
b. counter ions present
c. other solutes
d. temperature
e. pH
TYPE OF CARRAGEENAN
•
•
•
•
The many forms of carrageenan possible through variation in structural
detail, provide much variability in regard to solubility properties. For practical
purposes, however, it is convenient to speak in terms of several general
structural types and to equate solubility with the overall balance of
hydrophilicity as provided by the hydrophilic sulfate and hydroxyl groups on
one hand and the more hydrophobic 3.6-anhydro-D-galactose residues on
the other.
Thus, lambda carrageenan, by definition void of 3.6-anhydro-D-galactose
units and being highly sulfated is easily soluble under most conditions.
Kappa carrageenan containing 3.6-anhydro-D-galactose as part of the
repeating unit and fewer sulfate groups is less hydrophilic and less soluble.
Intermediate is iota carrageenan, more hydrophilic by virtue of its 2-sulfate
which in addition to its position counteracts the less hydrophilic character of
the 3.6-anhydro-D-galactose residue.
SOLUBILITY CARRAGEENAN IN MEDIUM/SOLVENTS
Medium
Kappa
Iota
Lambda
Hot water
Soluble above 60°C
(140°F)
Soluble above 60°C
(140°F)
Soluble
Cold water
Sodium salt soluble.
Potassium and calcium
salt, insoluble
Sodium salt soluble
Calcium salts gives
thixotropic dispersions
Soluble
Hot milk
Soluble
Soluble
Soluble
Cold milk
Sodium salt,
calcium salt and
potassium salt
insoluble, but swells
markedly
Insoluble
Soluble
Concentrated
sugar solutions
Soluble hot
Not easily soluble
Soluble hot
Concentrated
salt solutions
Insoluble
Soluble hot
Soluble hot
USAGE & STANDARDIZATION OF
CARRAGEENAN
• Carrageenan is used in concentrations from as low as 0.005% to as
high as 3.0% in a broad variety of products.
• Many types of carrageenan are made, some being standardized for
general use as a gelling agent in water or milk systems and some
being controlled by application tests, designed in cooperation
between the user and the manufacturer.
• Standardization is done by blending different batches of
carrageenan and/or by blending with an inert material such as
sucrose or dextrose.
• Standardization of carrageenan with sugar is recognized in the EU
stabilizer directive and the FAO/WHO-specification.
QUALITY CONTROL
• Carrageenan has a high (natural) ash content,
originating from the sulfate half ester groups
and the cations. On ashing, some of the
sulfate evaporates as SO3, and the ash
content is accordingly found to be lower than
expected from SO4 and cation content
STABILITY
• Carrageenan will depolymerize slowly when stored. As
the two most important properties of carrageenan, gel
strength and protein reactivity, are hardly dependent on
degree of polymerization, the loss in strength over a
period of one year at room temperature is undetectable.
• It is generally undesirable to blend a carrageenan
powder with other powdered or crystalline ingredients of
an acidic nature. However, when specific precautions are
taken, it is possible to make stable blends of
carrageenan and citric acid for example.
Gel Properties
Gel Formation
• Carrageenan is a thermoreversible gelling
agent. Gel formation is obtained only in the
presence of potassium ions (kappa and iota
carrageenan)
or
calcium
ions
(iota
carrageenan).
• When potassium ions are present, and the
system is cooled below the gelling
temperature,
the
carrageenan
gels
instantaneously.
GELLING PROPERTIES
Kappa
Iota
Lambda
Effect of cations
Gels most strongly
Gels most strongly
with potassium ions with calcium ions
Non-gelling
Type of gel
Strong and brittle
with syneresis
Elastic and cohesive Non-gelling
without
syneresis
Synergistic effect
with locust bean
gum
High
High
None
Freeze/thaw
stability
None
Stable
None
SELECTION GUIDE FOR
CARRAGEENAN
• GENULACTA types find application in milk
systems
GENUGEL types find application in water
systems
GENUVISCO types are used as thickening
agents/stabilizing agents
Tugas membaca
• Find out :
• Baca Perbedaan gelling properties of AGAR
dengan CARRAGEENAN.