ISO INTERNATIONAL STANDARD 11052 First edition 1994-09-01 Durum wheat flour and semolina Determination of yellow pigment content Farines et semoules de blé dur Determination de la teneur en pigments jaunes ISO Referencenumber ISO 11052:1994(E) IS011052:1994(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC)on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 11052 was prepared by Technical Committee ISO/TC 34, Agricultural food products, Subcommittee SC 4, Cereals and pulses. Annexes A and B of this International Standard are for information only. ?ISO1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56.CH-1211Geneve 20:Switzerland Printed in Switzerland INTERNATIONALSTANDARDISO IS011052:1994(E) Durum wheat flour and semolina Determination of yellow pigment content Scope 1 evaluation of the optical density of the clear filtrate against β-carotene standard solutions. This International Standard specifies a method for determination of the yellow pigment content in durum Reagents wheatflourandsemolina(TriticumdurumL.), Use only reagents of recognized analytical grade and 2 Normative reference distilled or demineralized water or water of at least equivalent purity. The following standard contains provisions which, through reference in this text, constitute provisions 5.1 Water-saturated n-butanol of this International Standard. At the time of publica- tion, the edition indicated was valid. All standards are Prepare a solution of n-butanol and water in pro- subject to revision, and parties to agreements based portions 6:2 (V/V) and shake vigorously. Use the clear on this International Standard are encouraged to in- upper layer after separation of the phases. vestigate the possibility of applying the most recent edition of the standard indicated below.Members of 5.2 Diethyl ether IEC and ISO maintain registers of currently valid International Standards. 5.3Synthetic β-carotene, crystalline, finely crushed. Iso 712:1985, Cereals and cereal products - Deter- mination of moisture content (Routine reference method). 6 Apparatus Usual laboratory apparatus and, in particular, the fol- 3 Definition lowing. For the purposes of this International Standard, the 6.1 Grinder, having the following properties: following definition applies. constructed of a material that does not absorb 3.1 yellow pigment content:An essential quality water; factor of raw materials for the production of pasta, defined as the content of extractable carotenoids of - easy to clean; the endosperm. - of minimal dead space; It is expressed as milligrams of β-carotene in 100 g of dry matter. capable of grinding rapidly and uniformly without heating, and avoiding as far as possible contact of 4Principle the sample with the outside air. Extraction of the carotenoids at room temperature 6.2 Spectrometer, capable of operating at a wave- withwater-saturatedn-butanol.Thenphotometric length of 440 nm.