International Standard (ISo 1743 INTE RNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAR OPrAHW3AMA nO CTAHAAPTW3AUWW-ORGANISATION INTE RNATIONALE DE NORMALISATION Glucose syrup - Determination of dry matter content - Refractive index method Sirops de glucose -- Détermination de la teneur en matiere seche - Methode réfractométrique Second edition - 1982-05-15 UDC 664.162 : 543.814 Ref. No. ISO 1743-1982 (E) ISO 1743-1982 (E) Descriptors : carbohydrates, glucose, tests, determination of content, dry matter, refractivity. Price based on 11 pages Copyright International Organization for Standardization ted without license from IHS Not for Resale 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 1743 was developed by Technical Committee ISO/TC 93, Starch (including derivatives and by-products), and was circulated to the member bodies in November 1979. It has been approved by the member bodies of the following countries : Netherlands Spain Australia Canada Philippines USA Ethiopia Poland USSR Germany, F.R. Romania Yugoslavia Korea, Rep. of South Africa, Rep. of No member body expressed disapproval of the document. This second edition cancels and replaces the first edition (i.e. 1S0 1743-1973). International Organization for Standardization, 1982 Printed in Switzerland ed withoutlicense from IHS Not for Resale INTERNATIONAL STANDARD ISO 1743-1982 (E) Glucose syrup - Determination of dry matter content Refractive index method 1 Scope and field of application 4.3 Light source : full daylight or an incandescent bulb (25 to 50 W) or other light source recommended by the manufac- This International Standard specifies a method for the deter- turer of the refractometer, arranged so that the light falls on the mination of the dry matter content of glucose syrups on the illumination prism or mirror. basis of their refractive index. The method is also applicable to glucose syrup containing fruc- tose. 5 Procedure 5.1 Preparation of test sample Reference Use the product as received. ISO 5377, Starch hydrolysis products Determination of reducing power and dextrose equivalent -- Lane and Eynon 5.2 Preparation of apparatus constant titre method. Adjust the water circulation to operate at the required 3 Principle temperature (20 ± 0,2 °C or 30 ± 0,2 oC or 45 ± 0,2 oC or 60 ± 0,2 °C) and to bring the prisms to the same temperature Determination of the refractive index of an undiluted product, (see 8.3). at a specified temperature; calculation of the dry matter con- tent by means of tables showing refractive index as a function 5.3 Determination of composition, concentration and temperature. Bring the test sample (5.1) to the measuring temperature and apply a small quantity of this test sample to the fixed prism of 4 Apparatus the refractometer (4.1), by means of the glass rod (4.2), and im- mediately ciamp down the movable prism (see 8.4). 4.1 Refractometer, Abbe type or similar (see 7.1) allowing the reading or the estimation of refractive indices of between Generally, 1 to 3 drops suffice to fill uniformly the space be- 1,300 0 and 1,550 0 to the nearest 0,000 2 unit. tween the prisms. (lf the quantity is too small, the contrast is in- sufficient when reading is attempted.) It shall be so designed that samples can be introduced easily and rapidly, and shall be easy to clean. The instrument shall be With the instrument suitably illuminated, read or estimate the provided with a