Optimising the winemaking process: NIR spectroscopy and e‐nose analysis for the online monitoring of fermentation

Background: In winemaking process the rapid determination of specific quality parameters like sugar content, pH, acidity, concentrations of phenolic compounds, anthocyanins, and volatile organic compounds (VOCs) is crucial for high-quality wine production. Traditional analytical methods allow for precise quantification of these parameters but are time-consuming and expensive. This article explores the potential application of non-destructive analytical techniques, NDAT (NIR and e-nose), as efficient alternatives for online monitoring of fermentation working on two different winemaking tanks and applying chemometrics to develop predictive models to correlate non-destructive and analytical data. Results: NIR measurements have been used to build PCR models, showing good prediction capability for polyphenols, anthocyanins, glucose, and fructose. Both offline and online e-nose application demonstrates good capability of discriminating different fermentation phases, in agreement with aromatic profile changes observed via GC-MS analysis. Moreover, correlation analysis reveal the potential of QMB, TGS and H2 S in predicting the concentration of compounds of great interest for winemaking (e.g. C6 alcohols, ketones, terpenes, ethyl esters) highlighting the robust connection between sensor data and specific chemical classes. Conclusions: This research aims to showcase the potential employment of NDAT for online monitoring the evolution of must composition during fermentation. The proposed methods could potentially fulfil a longstanding requirement of winemakers, enabling them to closely monitor fermentation allowing the timely making of important technical decisions aimed at achieving oenological objectives in wine production. This article is protected by copyright. All rights reserved.