Voltammetry pulse array developed to determine the antioxidant activity of camu-camu (Myrciaria dubia (H.B.K.) McVaug) and tumbo (Passiflora mollisima (Kunth) L.H. Bailey) juices employing voltammetric electronic tongues

•Camu-camu and tumbo, two tropical fruits rich on vitamin C.•Antioxidant capacity of fruits is expressed depending on the method used.•Cyclic voltammetry characterizes electrochemical processes (oxidation-reduction).•Pulse voltammetric tongue is based on a set of sensors (metallic electrodes).•Voltammetric electronic tongues can predict the antioxidant capacity of some fruits.

A pulse voltammetry electronic tongue can be a useful tool for determining the antioxidant capacity of fruit extract with minimum handling given the large number of electrodes it has. However, it is necessary to define the array of pulses to be applied to each electrode in order to obtain a pattern that characterize this property. In this study, from a generic array of 22 pulses (applying potentials between −800 and 900 mV for 20 ms each) and by employing statistical procedures (multivariate analysis), the best arrays of pulses has been defined to determine the antioxidant capacity of two Peruvian fruits (camu-camu and tumbo) for each electrode to constitute the pulse voltammetry electronic tongue (Au, Pt, Ir, Rh, Ag, Cu, Ni, and Co). Three arrays were obtained, one employing all 22 pulses applied to each electrode, which generated a large number of data, and two in which pulses and electrodes were reduced. Accordingly, the best one only used 3.4% of the initial voltammetry information, obtained from pulses at 900 and −850 mV and applied to electrodes Ir and Au, and another at −600 mV on an Ni electrode.