5566 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAA OPTAHM3ALWA NO CTAHAAPTW3AUMWORGANISATION INTERNATIONALE DE NORMALISATION Turmeric - Determination of colouring power - Spectrophotometric method Curcuma -- Détermination du pouvoir colorant - Methode spectrophotometrique First edition - 1982-11-15 ISO 5566-1982 (E) UDC 664.59 : 543.42 Ref.No. ISO 5566-1982 (E) Descriptors : turmeric, chemical analysis, determination, colouring power, spectrophotometric analysis. Price based on 2 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (isO member bodies). The work of developing Inter- national Standards is carried out through Iso technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental 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 Committee ISO/TC 34, Agricultural food products, and was circulated to the member bodies in May 1981. it has been approved by the member bodies of the following countries: Brazil Korea, Rep. of Spain Canada Malaysia Sri Lanka Czechoslovakia Mexico Tanzania Egypt, Arab Rep. of Netherlands Thailand Ethiopia New Zealand Turkey France Peru United Kingdom Hungary Poland USSR india Portugal Yugoslavia Israel Romania Italy South Africa, Rep. of No member body expressed disapproval of the document. International OrganizationforStandardization,1982 Printed in Switzerland ISO5566-1982 (E) INTERNATIONALSTANDARD Turmeric - Determination of colouring power Spectrophotometric method Scope and field of application 6.4 Spectrophotometer, suitable for making measure ments of absorbanceat425nm. This International Standard specifies a spectrophotometric method for the determination of the colouring power of tur- 6.5 Matched spectrophotometric cells (of silica), of op- meric. tical path length 1 cm. 2 References 6.6 Analytical balance. Iso 948, Spices and condiments - Sampling. Sampling iso 2825, Spices and condiments -- Preparation of a ground sample for analysis. Sample the product by the method specified in iso 948. 8Procedure 3Definition colouringpower of turmeric :The curcuminoids content of 8.1 Preparation of the test sample turmeric,expressed as curcuminasapercentagebymass Prepare the sample by the method specified in ISO 2825. The degree of fineness of grinding used shall be about 500 μm. 4Principle Ground (powdered) turmeric is analysed as received, without Extraction of the pigments of turmeric with hot ethanol, dilu- preparation, the degree of fineness usually being appropriate. tion of the extract and spectrophotometric measurement at the wavelength of maximum absorption (i.e. 425 nm). 8.2Test portion Weigh, to the nearest 0,001 g, about 0,5 g of the ground 5Reagent sample. 5.1 Ethanol, 96 % (V/ W. 8.3 Determination Place the test portion in the extraction flask (6.1), add 30 mi of the ethanoi (5.1) and boil under reflux for 2,5 h. Allow the ex Apparatus tract to cool and filter quantitatively into the 100 ml volumetric flask (6.3). Wash the residue on the filter thoroughly, collecting Usual laboratory apparatus, and in particular the washings inthe volumetricflask.Dilutethe contents of the flask to the mark with the ethanol (5.1). 6.1 Round-bottomed extractionflask,ofcapacity100ml, fitted with a reflux condenser. Transfer,by means of the pipette (6.2),5 ml of the filtered ex- tract to the250 ml volumetric flask(6.3).Dilite to the mark