| Abstract: | An automated colorimetric method, using p-hydroxybenzoic acid hydrazide and 2-thiobarbituric acid as colour reagents for the determination of total reducing sugars and fructose respectively, is described. The normal measurement range of reducing sugars is 50–1500 mg litre?1, but with a simple modification of the autoanalyser arrangement it can be reduced to 1–30 mg litre?1 or increased to 500–6000 mg litre?1 without affecting the linearity of the calibration curve. Recovery of sugars by the known addition technique using this method range from 97 to 104%. The method is applicable for the joint determination of glucose, fructose and sucrose in fruits, vegetables and fermentation liquors. |
