48519030040102 5377-81 nternational Standard (ISO 5377 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION+MEKAYHAPOAHAH OPFAHM3ALMR NO CTAHAAPTW3AUWWORGANISATION INTERNATIONALE DE NORMALISATION Starch hydrolysis products - Determination of reducing power and dextrose equivalent - Lane and Eynon constant titre method Produits d'hydrolyse de I'amidon ou de la fécule - Deétermination du pouvoir réducteur et de I'équivalent en dextrose - MethodeLaneetEynonatitreconstant First edition - 1981-12-15 UDC664.28:664.162.036:543.24 Ref.No.ISO5377-1981(E) 5377-1981 Descriptors : starches, tests, determination, mass losses, dry matter, titration. 8 Pricebasedon6pages CoPyRIGHTInternationalOrganizationforStandardization 4851903 0040103 3 5377-81 Foreword 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 and non-governmental, 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 5377 was deveioped by Technical Committee ISO/TC 93, Starch (including derivatives and by-products),and was circulated to the member bodies in November 1980. Ithas beenapproved bythememberbodies ofthefollowing countries : Australia Netherlands Austria Romania Egypt, Arab Rep. of South Africa, Rep. of France USA Iran USSR No member body expressed disapproval of the document. @InternationalOrganizationforStandardization,1981 Printed in Switzerland COPYRIGHT International Organization for Standardization INTERNATIONALSTANDARD 5 ISO 5377-1981 (E) 5377-81 Starch hydrolysis products - Determination of reducing power and dextrose equivalent t - Lane and Eynon constant titre method Scope and field of application 4Principle This International Standard specifies a Lane and Eynon cons- Titration of a prescribed volume of mixed Fehling's solution tant titre method for the determination of the reducing power with a solution of a test portion under specified conditions, and dextrose equivalent of all starch hydrolysis products. using methylene blue as internal indicator. 2 References 5 Reagents Iso 385/1, Laboratory glassware Burettes Part 1: During the analysis, use only reagents of recognized analytical General requirements. i) grade and only distilled water or water of equivalent purity. Iso 385/2, Laboratory glassware - Part 2: Burettes for which no waiting time is specified.1) 5.1 Fehling's stock solutions Iso 648, Laboratory glassware - One-mark pipettes. Prepare the following solutions, using apparatus in accordance with clause 6. Iso 1042, Laboratory glassware - One-mark volumetric flasks. Iso 1741, Dextrose Determinationof lossinmassondrying 5.1.1 Stock solution A - Vacuum oven method. Copper(lI) sulphate pentahydrate 69,3 g 1so 1742, Glucose syrup -Determination of dry matter con- (CuS04-5H20) tent - Vacuum oven method. Water to 1 000,0 ml Iso 1743,Glucose syrupand dextrose Determinationofdry .matter content - Refractive index method. 5.1.2 Stock solution B Iso 1773,Laboratory glassware - Boiling flasks (narrow- necked). Potassium sodiumtartrate tetrahydrate 346,0 g (KNaC4H406-4H20) Iso 5809, Starch, including derivatives and by-products Sodium hydroxide (NaOH) 100,0 g Determination of sulphated ash.2) Water to 1 000,0 ml 3Definitions Before use, decant the clear solution from any sediment that may form. 3.1 reducing power : The content of reducing sugars, ex- pressed as the number of grams of anhydrous D-glucose per 5.1.3 Mixed Fehling's solution 100 g of the sample, when determined by the method specified in this International Standard. Transfer into a dry stock glass bottle, in the followi