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1、International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONWlEYHAPOHAR OPrAHM3AlWl fl0 CTAHJJAPTM3ALWl6RGANISATION INTERNATIONALE DE NORMALISATION Turmeric - Determination of colouring power - Spectrophotometric method Curcuma - Determination du pouvoir colorant - Mbthode spectropho tomhtr
2、ique First edition - 1982-11-15 UDC 664.59: 543.42 Ref. No. ISO 55664982 (E) Descriptors : turmeric, Chemical analysis, determination, colouring power, spectrophotometric analysis. Price based on 2 pages Copyright International Organization for Standardization Provided by IHS under license with ISO
3、Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:28:34 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword EIS0 (the International Organization for Standardization) is a worldwide federation of national Standards institutes (SS0 member bodie
4、s). The work of developing lnter- national Standards is carried out through ISO technical committees. Every member body interested in a subject for which a technicai committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governm
5、ental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO 5566 was developed by Technical
6、 Committee ISO/TC 34, Agrieultwal food products, and was circulated to the member bodies in May 1981. lt has been approved by the member bodies of the following countries: Brazil Canada Czechoslovakia Egypt, Arab Rep. of Ethiopia France Hungary lndia Israel Italy Korea, Rep. of Malaysia Mexico Nethe
7、rlands New Zealand Peru Poland Portugal Romania South Africa, Rep. of No member body expressed disapproval of the document. Spain Sri Lanka Tanzania Thailand Turkey United Kingdom USSR Yugoslavia International Organkation for Standardkation, 1982 Printed in Switzerland Copyright International Organi
8、zation for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:28:34 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 55664982 (E) Turmeric - Determination of colouring
9、 power - Spectrophotom 1 Scope and field of application This International Standard specifies a spectrophotometric method for the determination of the colouring power of tur- meric. 2 Ref erences ISO 948, Spices and condiments - - Sampling. ISO 2825, Spices and condiments Sample for analysis. - - Pr
10、eparation of a ground 3 Definition colouring power of turmeric : The curcuminoids content of turmeric, expressed as curcumin as a percentage by mass. 4 Principle Extraction of the Pigments of turmeric with hot ethanol, dilu- tion of the extract and spectrophotometric measurement at the wavelength of
11、 maximum absorption (i.e. 425 nm). 5 Reagent 5.1 Ethanol, 96 % (VW). 6 Apparatus Usual laboratory apparatus, and in particular 6.1 Round-bottomed extraction flask, of capacity 100 ml, fitted with a reflux condenser. 6.2 Pipette, of capacity 5 mI. 6.3 Qne-mark volumetric flasks, of capacities 100 and
12、 250 ml. 6.4 Spectrophotometer, suitable for making measure- ments of absorbance at 425 nm. 6.5 Matched spectrophotometric cells (of silica), of op- tical path length 1 cm. 6.6 Analytical balance. 7 Sampling Sample the product by the method specified in ISO 948. 8 Procedure 8.1 Reparation of the tes
13、t Sample Prepare the Sample by the method specified in ISO 2325. The degree of fineness of grinding used shall be about 500 pm. Ground (powdered) turmeric is analysed as received, without preparation, the degree of fineness usually being appropriate. 8.2 Test Portion Weigh, to the nearest 0,001 g, a
14、bout 0,5 g of the ground Sample. 8.3 Determination Place the test Portion in the extraction flask (6. l), add 36 ml of the ethanol (5.1) and boil under reflux for 2,5 h. Allow the ex- tract to cool and filter qudntitatively into the 100 ml volumetric flask (6.3). Wash the residue on the filter thoro
15、ughly, collecting the washings in the volumetric flask. Dilute the contents of the flask to the mark with the ethanol (5.1). Transfer, by means of the pipette (6.21, 5 ml of the filtered ex- tract to the 250 ml volumetric flask (6.3). Dilute to the mark with the ethanol. Fill one of the spectrophoto
16、metric cells (6.5) with this Solution and fill the other with the ethanol. Measure the absorbance (R) at 425 nm using the ethanol as the reference liquid. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001
17、Not for Resale, 04/25/2007 20:28:34 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 55664982 (E) 9 Expression of results The colouring power of turmeric, expressed as curcumin as a percentage by mass, is equal to A x D x 100 m is the mass, in grams, of the test Portion.
18、 NOTE - The result may also be expressed on the dry basis by means of the formula El % A x 50 x 100 x 100 lcm m 1607 x rn x (100 - H) Ax50xloo = 1607xm where A is the measured absorbance; D is the dilution of the extract, i.e. 100 250 -= -x 100 5 50 El % 1 cm is the specific absorbance of a 1 % solu
19、tion of cur- cumin measured at 425 nm in cells of Optical path length 1 cm, i.e. 1 607; where His the moisture content of the Sample, expressed as a percen- tage by mass. 10 Test report The test report shall show the method used and the results ob- tained. lt shall also mention all operating conditi
20、ons not speci- fied in this International Standard, or regarded as optional, as weil as any circumstances likely to have influenced the results. The test report shall include all the information necessary for the complete identification of the Sample. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:28:34 MDTNo reproduction or networking permitted without license from IHS -,-,-