Prevention of b-Glucosidase Inhibition by High Molecular Mass Compounds During Enzymatic Wine Aroma Enhancement Using a Hollow Fiber Reactor

Enzyme activity and stability in a membrane reactor for wine aroma enhancement can be higher than when the enzyme is present in a free state since the catalyst would only be in contact with the low molecular mass components of this beverage. To test this hypothesis, the activity and stability of two commercial -glucosidases were measured in the presence of Tannat wine and of its low molecular mass fraction (<10 kDa) obtained by ultrafiltration. The relative activities of Endozym Rouge and Endozym -split -glucosidases were higher in this fraction (3.8 and 7.6 %, respectively) than in the whole wine (0.9 and 5.6 %, respectively). Both enzymes were also more stable in the low molecular mass fraction. Endozym -split -glucosidase retained about 75 % of its initial activity after 14 days in the low molecular mass fraction, as contrasted with only 37.5 % in the wine. The ability of Endozym Rouge -glucosidase to hydrolyze the synthetic substrate p-nitrophenylglucoside was examined in a simple batch membrane reactor. A rate of hydrolysis comparable to that obtained with the free Endozym Rouge -glucosidase was reached. Finally, Endozym -split -glucosidase was used to hydrolyze the synthetic substrate in a hollow fiber membrane reactor and a substrate conversion near 58 % was achieved.