Discrimination among milks and cultured dairy products using screen-printed electrochemical arrays and an electronic nose

Electrochemical arrays were constructed by screen-printing. The arrays consisted of four members derived from carbon inks containing platinum, palladium, rhodium and a proprietary mediator. Differential pulse voltammetry was used to generate data for multivariate analysis. Using this analysis it was possible to discriminate among cultured and non-cultured dairy products, among milks and a range of yoghurts. An e-nose was also used to discriminate among the various samples but as both approaches succeeded in discrimination there was nothing to be gained by combining data from the two instruments. Analysis of differential pulse voltammograms (DPVs) from single electrodes indicated that these may achieve discrimination, i.e. a multi-membered array may not be necessary. Screen-printing may enable arrays to be manufactured sufficiently inexpensively to be disposable, thus avoiding the necessity to polish or electrochemically clean arrays between successive samples.