SYNONYMS |
INS No. 474 |
DEFINITION |
Sucroglycerides are obtained by reacting sucrose with an edible fat or oil with or without the presence of a solvent. They consist of a mixture of mono- and di-esters of sucrose and fatty acids together with mono-, di- and triglycerides from the fat or oil. Only the following solvents may be used in the production: dimethyl formamide, cyclohexane, isobutanol, isopropanol and ethyl acetate. |
Assay |
Not less than 40% and not more than 60% of sucrose esters |
DESCRIPTION |
Odourless, soft, solid masses, white to off-white powders, or stiff gels |
FUNCTIONAL USES |
Emulsifier |
CHARACTERISTICS |
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IDENTIFICATION |
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Solubility |
Insoluble in cold water; soluble in ethanol |
Test for fatty acids |
Passes test See description under TESTS |
Test for sugar |
Passes test See description under TESTS |
PURITY |
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Sulfated ash |
Not more than 2% Proceed as directed under the test for Ash (Sulfated ash, Method I) using 1 g of the sample |
Acid value |
Not more than 6 |
Free sucrose |
Not more than 5% See description under TESTS |
Dimethyl formamide |
Not more than 1 mg/kg See description under TESTS |
Cyclohexane and isobutanol |
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Not more than 10 mg/kg, singly or in combination See description under TESTS |
Ethyl acetate and isopropanol |
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Not more than 350 mg/kg, singly or in combination |
Lead |
Not more than 10 mg/kg Prepare a sample solution as described for organic compounds in the Limit Test, using 10 m g of lead ion (Pb) in the control |
TESTS |
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IDENTIFICATION TESTS |
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Test for fatty acids |
Add 1 ml of ethanol to 0.1 g of the sample, dissolve by warming, add 5 ml of dilute sulfuric acid TS, heat in a water bath for 30 min and cool. A yellowish white solid or oil is formed, which is soluble in 3 ml of ether. |
Test for sugar |
To 2 ml of the solution separated from the solid or oil in the Test for fatty acids add 1 ml of anthrone TS carefully down the inside of the test tube. The boundary surface of the two layers turns to blue or green. |
PURITY TESTS |
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Free sucrose |
Determine by gas liquid chromatography using the following conditions:
Reagents: - Internal Standard: 5 mg/ml cholesterol in chloroform or 10 mg/ml tetracosane in chloroform - Pyridine (dried over molecular sieve) - N,O-Bis-(Trimethylsilyl)-acetamide (BSA) - Trimethylchlorosilane (TMCS)
Procedure: Weigh accurately 20-50 mg of the sample into a silylation vial, add 1 ml internal standard solution, 1 ml pyridine, and 0.5 ml each of BSA and TMCS. Seal vial, and heat at 70° for 30 min. Inject 1 m l into the gas liquid chromatograph.
Conditions: Column: - length: 0.3 m - diameter: 4 mm (i.d.) - material: glass - packing: Dexil Carrier gas: Nitrogen Flow rate: 40 ml/min Detector: FID Temperature programme: Hold for 1 min at 160°, then 160-375° at 15°/min.
Measure peak areas for sucrose and internal standard. The response factor (RF) is calculated from a number of gas liquid chromatography runs with standard solutions of sucrose containing internal standard.
Calculation:
and
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Dimethyl formamide |
Determine by hydrolysis to dimethylamine and analysis by gas liquid chromatography using the following conditions:
Reagents: - Dimethyl formamide - Dimethylamine hydrochloride - Methanol - Ethanol - Hydrochloric acid - Sodium hydroxide
Standard solutions: Prepare 4.47 mg/ml (equivalent to 4.0 mg/ml of dimethyl formamide) stock solution of dimethylamine hydrochloride in ethanol, and prepare standard solutions equivalent to 4, 2 and 1 m g/ml of dimethyl formamide, respectively, by dilution of the stock solution with 0.1% sodium hydroxide solution in ethanol.
Sample preparation: The apparatus for the hydrolysis is shown in the Appendix. Weigh accurately about 40 g of the sample into a 1000-ml round-bottomed flask. Add 500 ml of 5% methanolic solution of sodium hydroxide, and attach the flask to the apparatus. Set an Erlenmeyer flask containing 10 ml of 1% methanolic solution of hydrochloric acid to the apparatus. Heat the round-bottomed flask and let the content reflux for 1 hour, then distil to collect about 50 ml of the distillate while cooling water of the reflux condenser is stopped. Evaporate the distillate to almost dryness on a boiling water bath. Dissolve the residue with a small amount of ethanol, add 2.5 ml of 5% ethanolic solution of sodium hydroxide, and dilute to 25 ml with ethanol to prepare a sample solution.
Procedure: Inject 2 m l of the sample solution into the gas liquid chromatograph under the conditions below.
Calibration curve: Prepare a calibration curve by injecting each 2 m l of the standard solutions into the gas chromatograph.
Conditions: Column: - length: 2 m - diameter: 2 mm (i.d.) - material: glass - packing: 10% amine 220 and 10% KOH on 80/100 weak acid washed Chromosorb W - conditioning: Heat to 130° overnight with 5 ml/min of nitrogen flow rate Carrier gas: Nitrogen Flow rate: 17 ml/min Detector: FID Temperatures - injection port: 198±5° - column: 60°
Calculation:
where
CDFA = Concentration of dimethyl formamide C = Concentration of dimethyl formamide detected W = weight of sample taken |
Cyclohexane and isobutanol |
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Determine by gas liquid chromatography using the following conditions:
Reagents: - Dimethylformamide (GLC purity grade) - Cyclohexane (UV spectrophotometric grade) - Isobutanol (analytical grade)
Standard solutions: Prepare a 0.1% stock solution of cyclohexane and isobutanol in dimethylformamide by pipetting 130 m l of cyclohexane and 125 m l of isobutanol into dimethylformamide and making up the volume to 10 ml.
Prepare by dilution a range of solutions containing 5, 10 and 20 mg/kg of cyclohexane and isobutanol. Prepare a response curve by injecting 5 m l of these diluted standard solutions into the gas chromatograph under the conditions below.
Sample preparation: Weigh 5 g of sample to the nearest 10 mg into a flask with a ground glass stopper, add 5 g of dimethylformamide and warm to dissolve. Cool and inject 5 m l into the gas chromatograph under the conditions below.
Column: - length: 3 m - diameter: 4.5 mm - material: stainless steel - packing: 20% Carbowax 20 M on Chromosorb G 60/80 Carrier gas: Helium (1.6 bar) Detector: Flame ionization Temperatures - injection port: 130° - column: 130° - detector: 200°
Determine the concentration of cyclohexane and isobutanol in the sample solution (50%) by comparison with the standard solutions and multiply the concentration by two to convert the results to correspond to the original sucroglycerides. |
Isopropanol and ethyl acetate |
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Determine by gas chromatography with a head space sampler using the following conditions:
Reagents: - Isopropanol - Ethyl acetate
Standard solutions: Take each 1 g of isopropanol and ethyl acetate in a volumetric flask and add water to total volume of 100 ml, and prepare 0.02-0.4 g/100 ml solutions by dilution of this solution.
If necessary, prepare standard solutions containing up to 7 g/100 ml of isopropanol and ethyl acetate.
Procedure: Place 1 g (1.0 ± 0.1g) of powdered sample in a sample vial. Add 5 m l of water to the sample vial and seal it quickly with a septum. Set the sample vial in a pre-conditioned gas chromatograph and start the analysis under the below-mentioned conditions.
Calibration curve: Take 1 g of powdered sucrose esters of fatty acids, solvent free or known residual solvent contents, in a sample vial, add 5 m l of the standard solution and seal it quickly with a septum. Set the sample vial in a pre-conditioned gas chromatograph and start the analysis under the following conditions and obtain calibration curves for each solvent.
Column: - length: 30 m - diameter: 0.53 mm (i.d.) - material: Silica capillary - film: 100% methyl polysiloxane - conditioning: Heat to 60° for 2-3 h with approximately 10 ml/min of nitrogen Carrier gas: Nitrogen Flow rate: 5 ml/min
Detector: Flame ionization Temperatures: - injection port: 110° - column: 40° - detector: 110°
Head space sampler: - Sample volume: 1.0 g ± 0.1 g + 5 m l - Sample heating temp.: 80° - Sample heating time: 40 min - Syringe temperature: 85 ° 0 - Sample gas injection: 0.4 ml
Calculation:
Ci =Ai x Cfi x 1000
where
Ci = Concentration of solvent i (mg/kg) Ai = Peak area of solvent i (m v.sec.) Cfi = Conversion coefficient for solvent i (slope of the calibration curve)(m g/m v.sec) |
METHOD OF ASSAY |
Determine by high pressure liquid chromatography using the following conditions:
Sample preparation: Add about 250 mg of the sample, accurately weighed to a 50 ml volumetric flask. Dilute to volume with tetrahydrofuran, and mix. Filter through a 0.5-m m membrane filter.
Procedure: Inject 100 m l of the sample into the pre-stabilized high pressure liquid chromatograph.
Conditions: Column: Styrene-divinylbenzene copolymer for gel permeation chromatography (TSK-GEL G2000 (Supelco) or equivalent) Mobile phase: HPLC-grade degassed tetrahydrofuran Flow rate: 0.7 ml/min Detector: Refractive index detector Temperatures: Column: 38° Detector: 38°
Record the chromatogram for about 90 min. Calculate the percentage of sucrose ester content in the sample taken by the formula:
100 A/T
where
A = the sum of peak areas for the three main components, the mono-, di-and triesters, eluting at about 65, 68 and 73 min, respectively T = the sum of all peak areas eluting within 90 min |