Methods

ISI 16-2e Determination of Alkali Fluidity 1. Scope The method is applicable to thin-boiling starches  (acid treated, oxidised) LT 30.11.1964 Rev. LT 25. Aug. 2000 2. Principle Viscosity by the use of a standard funnel   3. Apparatus 3.1 Analytical balance weighing to the nearest 0.1 mg. 3.2 Funnel approx. Ø 9 cm with short stem and glass tip allowing 100 ml water at 25 o C to run out in 70 s +/- 1s, when filled with 110 ml of water. 3.3 Stopwatch 3.4 Water bath with thermostat 3.5 Measuring beaker 100 ml 4. Reagents 4.1 Sodium hydroxide 0.25N 5. Procedure Weigh sample equivalent to 4.500 g starch dry matter to the nearest mg in a 250 ml beaker Add 10 ml distilled water and stir with a glass spatula See note. Gelatinising Add 90 ml (4.1) alkaline and stir 3 min. with a glass spatula The starch solution shall be 25  o C +/- 1  o C. Use water bath (3.4) Approx. 70 RPM Measuring Add 110 ml of water at at 25 o C. Note the exact time in sec.   for 100 ml of water to run out of the funnel (