CAROTENES (Algae)
Prepared at the 51st JECFA (1998), published in FNP 52 Add 6 (1998)
superding specifications prepared at the 44th JECFA (1995), published in
FNP 52 Add 3 (1995). No ADI allocated at the 41st JECFA in 1993. Metals
and arnic specifications revid at the 59th JECFA (2002).
SYNONYMS Natural ß-carotene, carotenes-natural; INS No. 160a(ii); CI (1975) No. 75130;
CI (1975) No. 40800 (ß-Carotene)
DEFINITION Carotenes (algae) are obtained by solvent extraction of the dried Dunaliella
salina (syn. D. bardawil and D. Kone). The main colouring principles are trans
我想见你 英文and cis -ß-carotene together with minor amounts of other carotenoids such as
时态alpha-carotene and xanthophylls. Besides the colour pigments, carotenes
(algae) may contain lipids, naturally occurring in the source material, food
grade vegetable oil, and tocopherol added to retard oxidation of the pigment.
The only solvents ud for the extraction are carbon dioxide, acetone,
methanol, propan-2-ol, hexane, ethanol and vegetable oil.
The main articles of commerce are suspensions in food grade vegetable/plant
oil. Others are liquid in food grade oil, dispersion in water using food additive
emulsifier, and as a powder using a pulverizing agent such as dextrin. This is
for ea of u and to improve stability as ß-carotenes easily oxidize.
广交会英语怎么说Class Carotenoid
C.A.S. number 7235-40-7communicationerror
Chemical formula C40H56 (ß-Carotene)
Structural formula
疯狂英语中学版
referenceall-trans-ß-Carotene亚洲大学最新排名
IDENTIFICATION
Solubility (Vol. 4) Insoluble in water
Spectrophotometry (Vol. 4) A cyclohexane solution of the sample (1 in 200,000) shows maximum absorptions at 448 -457 and 474 - 486 nm
Colour reaction A spot of a solution of the sample in toluene (about 400 µg /ml of ß-carotene) on a filter paper turns blue 2-3 min after application of a spray or drop of 20%
solution of antimony trichloride solution in toluene.
PURITY
Residual solvents (Vol. 4) Not more than 50 mg/kg, singly or in combination, of acetone, hexane, methanol, ethanol and propan-2-ol
Tocopherols Not more than 0.5%
avio
See description under TESTS
Lead(Vol. 4) Not more than 5 mg/kg
Determine using an atomic absorption technique appropriate to the specified
level. The lection of sample size and method of sample preparation may be
bad on the principles of the method described in Volume 4, “Instrumental
Methods.”
TESTS
PURITY TESTS
Tocopherols Reagents
- Ethanol: Dehydrate as follows. Add 0.02% each of KMnO4 and KOH to
absolute ethanol (Reagent quality) and distil. Discard the first 5% of the
distillate and leave at least 5% in the distilling flask.
- Petroleum ether (bp. 30-60o): Distil prior to u.
- Ferric chloride Solution: Dissolve 1 g of ferric chloride in and make up to 500
ml with dehydrated ethanol. Store in a non-actinic glass flask.tzd
- alpha,alpha'-Dipyridyl Solution: Dissolve 1 g of alpha,alpha'-dipyridyl in and
make up to 220 ml with dehydrated ethanol. Store in a non-actinic glass flask.
Procedure
Transfer 0.1 g of the sample, accurately weighed, into a 25 ml volumetric
flask. Add a few ml of petroleum ether, and swirl to dissolve the sample. Add
东正教教堂
approximately 10 ml of ethanol. Boil petroleum ether by heating carefully on a
steam bath. Make up to volume with ethanol (first cool the flask and its
contents to room temperature). Pipet an aliquot into a cond volumetric flask,
and make up to volume with ethanol. The aliquot and flask size should be
such that on making up to volume this cond time the solution contains
approximately 15 mg tocopherol per 100 ml. Pipet 2 ml of the solution into a
third 25 ml volumetric flask. Add 1 ml of ferric chloride solution and begin
timing, using a stopwatch. Immediately add 1 ml of alpha,alpha'-dipyridyl
solution and mix thoroughly by swirling. Dilute to volume with ethanol and mix
again by shaking vigorously. Approximately 9.5 min after the timing began, fill the spectrophotometer cell. Exactly 10 min after the addition of ferric chloride, read the absorbance vs. ethanol at 520 nm. The readings should be between 0.2 and 0.8. Measure absorbance of a blank. For the blank u 2
ml of ethanol instead of the sample solution.
% Total Tocopherols is
where:
AD = Absorbance of sample - Absorbance of blank;
28.2 = Factor for alpha-, beta-, gamma- and delta- tocopherols;
L = Length of the spectrophotometer cell in cm;
CD = Concentration of the sample expresd as grams of sample in 100 ml of ethanol solution of which 2 ml was taken before adding ferric chloride solution
METHOD OF ASSAY Proceed as directed under Colouring Matters, Total Content by Spectrophotometry in Volume 4, using the following conditions: W (g) = amount to obtain adequate absorbance;
V1 = V2 = V3 = 100 ml; v1 = v2 = 5 ml;
A1%1 cm = 2500; and lambda max = 448 - 457 nm
