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-CYCLODEXTRIN

 

Prepared at the 53rd JECFA (1999) and published in FNP 52 Add 7 (1999), superseding specifications prepared at the 51st JECFA (1998), published in FNP 52 Add 6 (1998). ADI "not specified" (temporary), established at the 51st JECFA in 1998.

SYNONYMS

-cyclodextrin, -CD, cyclooctaamylose, cyclomaltooctaose

DEFINITION

A non-reducing cyclic saccharide consisting of eight -1,4-linked D-glucopyranosyl units manufactured by the action of cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) on hydrolysed starch followed by purification of the -cyclodextrin. Purification is carried out using one of the following procedures: precipitation of a complex of -cyclodextrin with a macrocyclic compound and subsequent extraction with n-decane followed by steam-stripping of the solvent; crystallization from the purified mother liquor containing -cyclodextrin obtained by chromatographic methods with ion exchange or gel filtration; membrane separation methods such as ultra filtration and reverse osmosis.

Chemical names

Cyclooctaamylose

C.A.S. number

17465-86-0

Chemical formula

(C6H10O5)8

Structural formula

 

Formula weight

1297

Assay

Not less than 98% on an anhydrous basis

DESCRIPTION

Virtually odourless, white or almost white crystalline solid

FUNCTIONAL USES

Carrier, flavour modifier, stabilizer

CHARACTERISTICS

 

IDENTIFICATION

 

Solubility (FNP 5)

Freely soluble in water; very slightly soluble in ethanol

Specific rotation (FNP 5)

[]25D: Between +173 and +180o (1% solution)

Reaction with iodine (FNP 5)

To 0.2 g of the sample in a test-tube add 2 ml of a 0.1 N iodine solution. Heat the mixture in a water bath and allow to cool at room temperature. A clear brown solution is formed.

Chromatography

The retention time for the major peak in a liquid chromatogram of the sample corresponds to that for -cyclodextrin in a chromatogram of reference -cyclodextrin (available from Consortium f�r Elektrochemische Industrie GmbH, M�nchen, Germany or Wacker Biochem Group, Adrian, MI, USA) using the conditions described in the METHOD OF ASSAY.

PURITY

 

Water (FNP 5)

Not more than 11% (Karl Fischer Method)

Volatile organic compounds

Not more than 20 mg/kg
See description under TESTS

Reducing substances (FNP 5)

Not more than 0.5% (as glucose)

Sulfated ash (FNP 5)

Not more than 0.1%

Lead (FNP 5)

Not more than 1 mg/kg
Reflux about 5 g of the sample, accurately weighed, with 30 ml nitric acid for 1 h. Remove the reflux condenser and attach a condenser to the flask. Continue to heat and collect the distilled nitric acid. Allow the residue to cool, add 20 ml of water and again allow to cool. Add 2 ml of orthophosphoric acid, dilute to 100 ml and determine the lead content of the solution by atomic absorption spectroscopy (FNP 5).

TESTS

 

PURITY TESTS

 

Volatile organic compounds

Dissolve 50 g of the sample in about 700 ml distilled water in a 1-litre round bottom flask and add a magnetic stirrer. Attach the flask to the lower part of a Bleidner apparatus (see Figure 1) and connect a 100-ml round bottom flask containing about 70 ml hexane and a few boiling stones to the other side of the apparatus. Fill the Bleidner apparatus with equal amounts of water and hexane and place a reflux condenser on the top. Heat both flasks with heating mantels to boiling. Stir the 1-litre flask well by the magnetic stirrer. Keep the content of the two flasks boiling for 8 h. After cooling remove the 100-ml flask and transfer the content to a 100 ml volumetric flask and fill to the mark with hexane.


Figure 1

Analyze the hexane solution by gas chromatography (FNP 5) using the following conditions:

Column

- length: 30 m

- diameter: 0.32 mm

- stationary phase: 95% dimethyl, 5% diphenyl polysiloxane, 0.25 �m

Injector: 280�

Temperature: 70� (4 min) - 250�, 10�/min

Carrier

- gas: nitrogen

- flow: 70 ml/min

Detection: FID, 280�

Calculate the area(s) under the peak for each volatile organic compound and convert it to mg/kg -cyclodextrin using the response factor of 8-cyclohexadecen-1-one. The response factor is determined from a calibration curve using 8-cyclohexadecen-1-one concentrations of 0.1-6 mg/100 ml hexane.

METHOD OF ASSAY

Determine by liquid chromatography (FNP 5)using the following condition:

Column

- length: 30 cm

- diameter: 7.8 mm i.d.

- packing: Silver bonded to sulfonated divinyl benzene-styrene copolymer (Aminex HPX-42A (Bio-Rad Laboratories) or equivalent

- particle size: 25 �m

Solvent: water

Flow rate: 0.3 - 1.0 ml/min

Temperature: 65 � 10�

Injection volume: 20 - 100 �l

Detector: differential refractometer

Sample solution: weigh 1.0 g of the sample and dissolve in 100 ml of water.

Calculation

Calculate the content of -cyclodextrin in the sample by the peak area percentage method using the following formula:

where

A = percentage of -cyclodextrin in the sample

B = peak area of -cyclodextrin in the chromatogram

C = the sum of the peak area of every peak recorded in the chromatogram

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