An Improved Colorimetric Method to Quantify Sugar Content of Plant Tissue

A modification of the phenol-sulphuric acid method to determine the bulk of soluble or insoluble sugars in plant tissue is proposed. The method is based on optimizing the phenol concentration to obtain equal colour yields for glucose, fructose and sucrose. The optimal phenol concentration is found to depend on the ethanol concentration of the measuring solution. The method is quick, easy and its costs are low, permitting its use in routine analysis.