Determination of adulterant in milk through the use of a portable voltammetric electronic tongue

The aim of this work was to evaluate the application of a portable voltammetric electronic tongue device based on PSoC technology and an electrochemical sensor array of polypyrrole in the discrimination of samples of fresh milk adulterated with starch. The results showed that the device is able to perfectly discriminate the adulterated samples, separating them into well differentiated groups according to the amount of adulterant. In addition, the analysis of the correlation circle showed that all the sensors in the array provide useful information for the classification of the samples. Additionally, the ability of the device to determine the concentration of adulterant was explored through a PLS regression analysis. The obtained results allow to establish that the electronic tongue device can be used for quantitative determinations. However, the concentrations can present an average variation of 4.54%. This small deviation is compensated with some advantages of the electronic language such as the short analysis time, the elimination of pretreatment of the samples, the ease of handling of the device and its portability.

Keywords: electronic tongue, milk, adulteration, electrochemical sensors, polypyrrole.