Study of the influence of micro-oxygenation and oak chip maceration on wine composition using an electronic tongue and chemical analysis

The influence of micro-oxygenation (MOX) and maceration with oak chips treatments on wine was studied on wine samples from three vintages produced in the Yarra Valley, Australia. A full factorial design was employed where two factors (MOX and oak chips treatments) had two levels and one factor (vintage) had three levels. Three replicated treatments were run for each factor's setting. Wine samples were analysed using conventional laboratory methods with respect to the phenolic wine compounds and colour attributes since the phenolic fraction of wine is most affected by both MOX and oak maceration treatments. The same wine samples were measured with an electronic tongue based on potentiometric chemical sensors. The significance of treatments and vintage effects on wine phenolic compounds was assessed using ANOVA and ANOVA-Simultaneous Component Analysis (ASCA). Cross-validation was used for the ASCA sub-model optimisations and permutation test for evaluations of the significance of the factors. Main effects of vintage and maceration with oak chips were found to be significant for both physicochemical and the ET data. Main effect of MOX treatment was also found significant for the physicochemical parameters. The largest effect on the phenolic composition of wine was due to its vintage, which accounted for 70% and 33% of total variance in the physicochemical and ET data respectively. The ET was calibrated with respect to the total phenolic content, colour density and hue and chemical ages 1 and 2 and could predict these parameters of wine with good precision.