A NEW ELECTROCHEMICAL METHOD FOR MEASUREMENT ORGANIC ACID CONTENT IN TROPICAL FRUITS BASED ON CONDUCTIVITY

S. Shiraishi
In order to estimate the quality of some tropical fruits an attempt was made to apply the electrochemical measurement of the organic acid content in fruit juices. An equation (1) is set up between the content of organic acid in sample solution (y), and the specific conductance of the properly diluted solution (x). Where, the proportionality constant (a) is associated with nature of organic acids, closely related to the dissociation constant of the acid, y = ax + b (1), and (b) is the constant due to the content of the strong electrolytes in sample solution. For mango fruits, the equation (2) was abtained. y (% as citric acid) = 0.0169x - 0.8529, r = 0.964 (2) For indian black berry, the equation (3) was obtained. y (% as citric acid) = 0.01713x - 0.7053, r = 0.983 (3) For pineapple fruits, the equation (4) was obtained. y (% as citric acid) = 0.01390x - 0.2938. r = 0.949 (4)

In this case, the fruit juice was diluted 300 times with water containing 0.01M imidazol, and the specific conductance (umho· cm-1) was measured at 30°C.

Shiraishi, S. (1992). A NEW ELECTROCHEMICAL METHOD FOR MEASUREMENT ORGANIC ACID CONTENT IN TROPICAL FRUITS BASED ON CONDUCTIVITY. Acta Hortic. 321, 203-210
DOI: 10.17660/ActaHortic.1992.321.20
https://doi.org/10.17660/ActaHortic.1992.321.20

Acta Horticulturae