Utilisation of first principal component extracted from gas sensor measurements as a process control variable in wine fermentation

Tokaj wine fermentation process was followed with complex off-line measurements using traditional instrumental methods, human sensory assessment and gas sensor headspace measurements. The first principal component (PC1) extracted from gas sensor responses was proposed as a process control variable. The chemical interpretation of PC1 was proposed. Based on multiple linear regression model, the PC1 was well explained with the alcohol content, organic acids and ethyl acetate concentration in fermenting medium. These compounds indicate the progress of fermentation process as well as the sensory quality of final wine. Additionally, the PC1 very well correlated with human sensory assessment of the intensity of odour and flavour of fermenting medium. Therefore, the potential of gas sensor array to provide an alternative to human operator control of wine fermentation control was indicated.