University of North Florida
Browse the Citations
-OR-

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

View Stuart Chalk's profile on LinkedIn

Wine Fermenting

Classification: Beverage -> alcoholic -> wine -> fermenting

Citations 4

"Monitoring Ethanol Production During Wine Fermentation Processes By A Pervaporation-enzymic Derivatization Approach"
Analyst 1998 Volume 123, Issue 11 Pages 2367-2372
F. Delgado-Reyes, I. Papaefstathiou, J. M. Fernández Romero and M. D. Luque de Castro

Abstract: A new procedure for on-line monitoring of ethanol production in the wine fermentation bioprocess is presented. The method combines the use of a pervaporation unit inserted in a continuous flow system with the use of enzymatic derivatization and fluorimetric detection as a way of improving both selectivity and sensitivity. The derivatization reaction was based on a two-step reaction involving alcohol oxidase (AOD) and horseradish peroxidase (POD) with fluorimetric detection at ex = 310 nm and em = 415 nm of the dimer formed. The efficiency of the derivatization reaction was tested using different flow injection approaches with either solution phase or immobilized biocatalysts (in normal or stopped-flow modes in both cases). Finally, the approach based on the stopped-flow mode and AOD/POD immobilization was selected for application to the continuous monitoring of ethanol production in an experimental laboratory built bioreactor prepared using baker's yeast as active cells. The method shows different linear ranges depending on the situation of the catalyst and the mode used, with excellent precision (RSD 3.0-5.5%) and a sampling frequency of 5 h-1. The use of this biosensing system was also tested by the standard addition method in the fermentation product with acceptable recoveries in all instances (90-105%). A fully automated approach to on-line bioprocess sample collection, dilution and monitoring of the fluorimetric product is also proposed.
Ethanol Pervaporation Enzyme

"Development Of A Biosensor For Monitoring Of Glycerol During Alcoholic Fermentation"
Biosens. Bioelectron. 1998 Volume 13, Issue 7-8 Pages 875-880
D. Compagnone*, M. Esti, M. C. Messia, E. Peluso and G. Palleschi

Abstract: A biosensor for the measurement of glycerol in FIA was constructed using covalently immobilized glycerokinase and glycerol-3-phosphate oxidase in conjunction with a Pt based hydrogen peroxide probe. Different immobilization strategies have been studied including random and asymmetric immobilization onto a polymeric support and immobilization onto two different membranes. The latter resulted in the best configuration for batch measurement. The most effective configuration for measurement in FIA was the immobilization of glycerokinase in a glass beads reactor coupled with glycerol-3-phosphate oxidase on a preactivated Immobilon AV membrane kept at the electrode surface. Using a 250 µL injection loop, 3 mmol ATP(Mg+2) in 0.1 M borate buffer pH 8.5 and a flow rate of 0.5 ml/min, a linear response in the 2 x 10^-6/10^-3 mol/l range and a detection limit of 5 x 10^-7 mol/l were obtained for glycerol. Lifetime of the glycerol-3-phosphate membrane was extended up to 1 month by storage in the working buffer containing 1% DEAE-dextran and 5% lactitol. More than 350 samples can be assayed with this system. The biosensor was used to monitor off-line glycerol production during alcoholic fermentations carried out at different pHs and temperatures.
Glycerol Sensor Electrode Immobilized enzyme Glass beads Process monitoring

"Biosensor For Online Monitoring Of Glycerol During Alcoholic Fermentation"
Ind. Bevande 1998 Volume 153, Issue 27 Pages 6-8
Esti, M.;Peluso, E.;La Notte, E.;Compagnone, D.;Palleschi, G.

Abstract: Glycerol, the most important secondary product of alcohol fermentation, contributes to the smoothness and viscosity of wines with favorable effects on taste. An electrochemical biosensor was developed for online monitoring of glycerol biosynthesis. Anal. parameters as pH, buffer composition, and cofactor concentration. were optimized. The lifetime of the sensor in working conditions was also evaluated. The biosensor was assembled by immobilizing glycerol-3-phosphate oxidase on polymeric membranes and glycerokinase on aminopropyl glass beads. The enzymatic membrane was placed in contact with the surface of a Pt electrochemical transducer for H2O2 detection. Glass beads with immobilized glycerokinase were packed to form a reactor connected with the enzyme electrode in a flow system. A cell with a wall-jet configuration was used to monitor glycerol levels by flow-through and flow injection analysis (FIA) in a 10^-5 to 10^-3 mol/L concentration. range. This system was used to measure glycerol levels during alcohol fermentation at different temperatures and pH values.
Glycerol Sensor Electrode Electrode Process monitoring Optimization Immobilized enzyme Aminopropyl glass Glass beads

"Monitoring Alcoholic Fermentation Of Red Wine By Electrochemical Biosensors"
Am. J. Enol. Vitic. 2003 Volume 54, Issue 1 Pages 39-45
Marco Esti, Giulia Volpe, Dario Compagnone, Giacomo Mariotti, Danila Moscone, and Giuseppe Palleschi

Abstract: Amperometric biosensors for the determination of glucose, fructose, ethanol, and glycerol were used to monitor alcoholic fermentation during red wine production in industrial-scale plants. Platinum-based probes, covered with appropriate enzyme membranes, were assembled in electrochemical flow-injection analysis systems. Before use, the biosensors were validated in must and wine samples by spectrophotometric procedures. The biosensors were applied during alcoholic fermentation in three wineries that used different red winemaking techniques. Results are reported and compared. Glucose, fructose, ethanol, and glycerol content varied with different kinetics corresponding to three characteristic phases: an early phase with no detectable variation of the analytes, an intermediate phase characterized by rapid sugar use, and a late phase with little variation of the concentration levels. In particular, glucose was consumed more rapidly than fructose, confirming that the former is the preferential sugar source for Saccharomyces cerevisiae. Experimental data demonstrated that the biosensors are useful tools for the close monitoring of alcoholic fermentation during industrial mass production of wine.
Glucose Ethanol Glycerol Fructose Electrochemical analysis Sensor Biochemical analysis Sensor Internal standard Process monitoring Process control