On-line Monitoring and Control of Fed-batch Fermentations in Winemaking
Michal Dabros,
Giorgio Genasci,
Lucien Blanchard,
Samuel Unterhofer,
Olivier Vorlet,
Ramón Mira de Orduña Heidinger,
Jean-Pascal Bourgeois
Affiliations
Michal Dabros
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland. [email protected]
Giorgio Genasci
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland
Lucien Blanchard
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland
Samuel Unterhofer
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland
Olivier Vorlet
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland
Ramón Mira de Orduña Heidinger
HES-SO, University of Applied Sciences and Arts Western Switzerland, Changins School of Viticulture and Enology, Route de Duillier 50, CP 1148, CH-1260 Nyon, Switzerland
Jean-Pascal Bourgeois
HESSO, University of Applied Sciences and Arts Western Switzerland, School of Engineering and Architecture of Fribourg, Institute of Chemical Technology, Boulevard de Pérolles 80, CP 32, CH-1705 Fribourg, Switzerland
The fermentation of yeast in fed-batch mode shows great potential in winemaking because it allows the concentration of sugars to be kept low and constant throughout the process which, in turn, reduces cell stress and leads to a significant decrease in the production of unwanted secondary metabolites. The implementation of this technique requires reliable on-line analysis of sugar and a robust control strategy to maintain sugar concentrations at defined levels over the course of the fermentation. In this study, a laboratory-scale setup was used to implement and assess a fully automated fed-batch fermentation of Saccharomyces cerevisiae in grape must. Total sugar levels were monitored in-line by FT-MIR ATR spectroscopy and kept constant at 50 g/kg by a modified PI controller regulating the must feed flow rate. Good setpoint tracking and disturbance rejection were achieved in fermentations of up to four days despite occasional yeast sedimentation on the ATR crystal. The controller parameter adaptation strategy needs to be optimized for longer fermentations.
