A Milk Test Based on Resistance against Electricity of Milk

I. Basic Experiments for Detection of preservative in Milk

Abstract

An attempt was made to detect any additional substance from the milk by applying a method for the determination of electric conductivity to the conventional milk test. In basic experiments, various kinds of preservative at different concentrations were added to milk samples, which were examined for the presence or absence of any relationship between the preservative of a given kind and a given concentration and its resistance against electricity. Investigation was carried out also on the kind of electrode.
As a result, the resistance against electricity varied with the kind and concentration of the preservative employed, indicating that the results might be available for practical purposes. Among different types of electrode examined, platinum and gold seemed to be excellent, as considered from their stability as well as their sensitivity.
On the other hand, it is likely that the value of resistance against electricity varies with the quality of milk. Therefore, further study may be required to clarify any relationship of the resistance against electricity with specific gravity, fat, minerals, and freshness of the milk. Then, it may be possible to discuss the correlationship between the presence of prevervative in a milk sample and the value of resistance against electricity of it, taking the conditions to be elucidated from such study into consideration.