Gamma cyclodextrin – JECFA specification


 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”, established at the 53rd JECFA in 1999.
SYNONYMSgamma-cyclodextrin, gamma-CD, cyclooctaamylose, cyclomaltooctaose
DEFINITIONA non-reducing cyclic saccharide consisting of eight alpha-1,4-linked D-glucopyranosyl units manufactured by the action of cyclomaltodextrin glucanotransferase (CGTase, EC on hydrolysed starch followed by purification of the gamma -cyclodextrin. Purification is carried out using one of the following procedures: precipitation of a complex of gamma-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 gamma-cyclodextrin obtained by chromatographic methods with ion exchange or gel filtration; membrane separation methods such as ultra filtration and reverse osmosis.
Chemical namesCyclooctaamylose
C.A.S. number17465-86-0
Chemical formula(C6H10O5)8
Structural formula
Formula weight1297
AssayNot less than 98% on an anhydrous basis
DESCRIPTIONVirtually odourless, white or almost white crystalline solid
FUNCTIONAL USESCarrier, flavour modifier, stabilizer
Solubility (Vol.4)Freely soluble in water; very slightly soluble in ethanol
Specific rotation (Vol.4)[alpha]25D: Between +173 and +180o (1% solution)
Reaction with iodine (Vol.4)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.
ChromatographyThe retention time for the major peak in a liquid chromatogram of the sample corresponds to that for gamma-cyclodextrin in a chromatogram of reference gamma-cyclodextrin (available from Consortium für Elektrochemische Industrie GmbH, München, Germany or Wacker Biochem Group, Adrian, MI, USA) using the conditions described in the METHOD OF ASSAY.
Water (Vol.4)Not more than 11% (Karl Fischer Method)
Volatile organic compoundsNot more than 20 mg/kgSee description under TESTS
Reducing substances (Vol.4)Not more than 0.5% (as glucose)
Sulfated ash (Vol.4)Not more than 0.1%
Lead (Vol.4)Not more than 1 mg/kgReflux 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).
Volatile organic compoundsDissolve 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 using the following conditions:Column- length: 30 m- diameter: 0.32 mm- stationary phase: 95% dimethyl, 5% diphenyl polysiloxane, 0.25 µmInjector: 280°Temperature: 70° (4 min) – 250°, 10°/minCarrier- gas: nitrogen- flow: 70 ml/minDetection: FID, 280°Calculate the area(s) under the peak for each volatile organic compound and convert it to mg/kg gamma-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 ASSAYDetermine by liquid chromatography 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 µmSolvent: waterFlow rate: 0.3 – 1.0 ml/minTemperature: 65 ± 10°Injection volume: 20 – 100 µlDetector: differential refractometerSample solution: weigh 1.0 g of the sample and dissolve in 100 ml of water.CalculationCalculate the content of gamma-cyclodextrin in the sample by the peak area percentage method using the following formula:A = (B / C) x 100whereA = percentage of gamma-cyclodextrin in the sampleB = peak area of gamma-cyclodextrin in the chromatogramC = the sum of the peak area of every peak recorded in the chromatogram