Crystallization and Reconstitution of Yeast Aconitase

The combination of flow injection analysis and the electrochemical method was investigated for measuring the organic acid content of citrus fruits. The controlled-potential four-electrode method was used for conductance measurements. The instrumentation of the measuring apparatus used in this study is defined. The optimum conditions of the flow system were as follows: injection volume 35 μ1, mixing coil length 100 cm, flow rate 20ml/min and dilution ratio of samples 1:130. A linear correlation between the peak conductivity and the organic acid content was obtained with high correlation coefficient (r=0.992). It is possible to analyze about 50 samples within an hour using the method, and the coefficient of variation with any given juice for 20 assays was less than 0.5%.