On-line monitoring and control of fed-batch fermentations in winemaking Michal Dabros & Olivier Vorlet Summer School on Advanced Biotechnology HES-SO//VS 06.09.2017
Haute École Spécialisée de Suisse Occidentale 2
Winemaking Common method of making white wine HARVEST CRUCH PRESS CLARIFICATION BOTTELING FILTRATION AGING FERMENTATION source : saq.com 3
Fermentation step Traditionaly a batch process Mainly tanks of 1 000 to 10 000 L Without agitation From a few days to a month https://www.tonnellerie-rousseau.com https://abk6cognac.wordpress.com 4
Sugar Ethanol Batch fermentation process Yeast eat sugar release CO 2 and ethanol and die 5
Sugar Ethanol Hyperosmotic stress High sugar concentration Low sugar concentration Little yeast Lots of sugar Stressful state for yeast Acetic Acid Acetaldehyde Other metabolic pathways Lots of yeast Little sugar 6
Effect of global warming - Higher concentration of sugar in must (and thus also of alcohol) - Higher environmental temperatures during fermentation High alcohol levels during fermentation require more alcohol-tolerant yeast strains. High sugar concentrations in must cause a stress response in yeast, which leads to increased formation of fermentation co-products, such as acetic acid. Mira de Orduña, R., 2010. Climate change associated effects on grape and wine quality and production. 7
Drosophila Suzukii - Observed in Switzerland since 2011 - Significant damage to vineyards in 2014 - Probably responsible for the increase of acetic acid in grapes Fredrik von Erichsen 8
Impact on wine quality High sugar level + Stressed yeast = Poor Wine Quality Source: winefolly.com 9
Sugar Ethanol Constant low sugar concentration Low sugar concentration Feed Fermentation tank Must tank 10
Batch vs. fed-batch: preliminary studies C. Frohman, D. Widmer, R. Mira de Orduña, Revue Suisse Viticulture, Arboriculture, Horticulture, 2014, 46 (3), 182. 11
Prototype for fed-batch fermentations 1. In-line measurement of sugar 2. Control of must feed 12
Prototype for fed-batch fermentations 2) Fermenter 3) Must tank 4) Thermostats 5) Feed pump 6) Temperature probe 7) IR-ATR probe for sugar measurement Cornelius Keg 20L 13
Mechanical aspect Must Tank Hole for IR-ATR probe ISMATEC rotary piston pump Cornelius Keg 20L Fermentation Tank Aquarium pump 14
Which measurement mode do we need? Off-line analysis Manual sampling Analysis in another laboratory by other operators At-line analysis Manual sampling Analysis in the same laboratory On-line analysis Automatic sampling Automated analysis and processing In-line analysis Without sampling In process analysis (Tank or pipe) 15
Overview of on-line and in-line methods Classical methods Viscosimeter Conductimeter ph-meter Physical properties Spectroscopic methods NIR, MIR, FT-IR, UV-VIS, Raman NMR MS, MALDI-TOF Composition, Structure Optical methods Fluorescence quenching Photoacoustic Composition Scattering methods Light Scattering X-ray Scattering Chromatographic GC HPLC, UPLC Structure, Morphology Composition, Structure 16
On-line measurement with flow cell Flow through cuvette with classical spectrometer Z-type X-type For absorption spectroscopy ( UV-VIS, IR,..) Sample IN Sample OUT W-type For emission spectroscopy (Fluorescence,..) ATR Crystal Detector IR Beam ATR Flow cell 17
In-line measurement with probe Transmission probe Measure of liquids Measure both transmitted and backscattered light Internal reflections may limit the rangeuv, VIS, NIR Reflectance probe Measure of solids, powders, turbid liquids Color measurement, Fluorescence UV, VIS, NIR ATR probe Measure of liquids, - - high concentration, turbid Ideal for samples with high optical density Crystal : Sapphire or Diamond UV, NIR 18
midir instruments used Perkin Elmer Spectrum 100 FT-IR with ATR Flow cell Mettler Toledo ReactIR IC10 with ATR probe Sample IN Sample OUT Detector ATR Crystal IR Beam 19
Measurement of sugar & EtOH Superposing spectra chemometric (PLS) calibration model 20
Contol of must feed rate e(t): control error = C(t) sugar,setpoint - C(t) sugar F(t): must feed rate (manipulated variable) 21
Adaptive PI Controller t F t F0 exp t KP e KI e t dt 0 F 0 : initial flow rate: 1 F0 X 0V0 Y X / S C Feed μ : specific growth rate of yeast K P, K I : proportional and integral gains 22
Result with PI Controller and on-line monitoring On-line measurement of sugars with a Perkin Elmer Spectrum 100 FT-IR spectrophotometer and ATR Flow cell 23
Pump speed Sugar Concentration Model Predictive Controller (MPC) Δt = 3 min X X X X X Error Setpoint 24
Concentration (g/l) Result with MPC and in-line monitoring 80 70 60 Sugar Sepoint Sugar Concentration Ethanol Concentration 50 40 30 20 10 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time (days) In-line measurement of sugars with a Toledo ReactIR IC10 spectrometer with ATR probe 25
Perspectives Scale-up (in time and in volume) Monitor the concentration of the secondary metabolites Implementation with improved fermentation conditions Assess impact on the final product quality Source: rantnow.com 26
Acknowledgments Prof. Ramón Mira Prof. Jean-Pascal Bourgeois Giorgio Genasci Lucien Blanchard Samuel Unterhofer Ludivine Andrey Steven Viollet HES-SO programme P1 27
Thank you for your attention myswitzerland.com hes-so.ch olivier.vorlet@hefr.ch +41 26 429 67 09 http://olivier.vorlet.home.hefr.ch michal.dabros@hefr.ch +41 26 429 68 79 http://michal.dabros.home.hefr.ch 28