ISI 40-1e Determination of Residual Juice in Potato Starch
Return 1. Scope The method is applicable to native potato starch OJB 1960 Rev. LT 17.12.99 2. Principle Peroxidase in potato juice oxidises benzidin (as a hydrogen-donor) by means of hydrogen peroxyde as a hydrogen-acceptor. H 2 O 2 + AH 2 = 2H 2 O 2 + A. A is colored 3. Apparatus 3.1 Test tube 4. Reagents 4.1 Diluted hydrogen peroxide, 0.3%. 1 ml 30% H 2 O 2 is diluted to 100 ml with distilled water. 4.2 Benzidine solution, 0.5%. =.50 g benzidin (H 2 NC 6 H 4 -C 6 H 4 NH 2 ) is dissolved in 5 ml concentrated acetic acid