Commercial enzyme preparations are used in winemaking to facilitate filtration, clarification and/or to release varietal aromas. -glucosidase activity of the enzyme preparations is involved in the hydrolysis of several compounds for the development of varietal wine flavour. On the other hands, esterase activity is involved in the hydrolysis of esters. Esters are an important group of volatile compounds produced by yeast during alcoholic fermentation. The aim of this study was to evaluate β-glucosidase and esterase activity of 17 commercial enzyme preparations. Commercial enzyme preparations were defined by the manufacturers for different technological applications (aroma release, extraction, clarification, filtration). β-glucosidase and esterase activity both by means of a fluorimetric micro-plate assay was determined. β-glucosidase activity was measured as the amount of 4-methylumbelliferone (4-MU) released from 4-methylumbelliferyl--D-glucopyranoside (4-MUG) used as substrate of the reaction. β-glucosidase activity was expressed as nmol 4-MU/min/mg of powder. Esterase activity was measured as the amount of 5(6)-carboxifluorescein (cF) released from 5(6)-carboxifluorescein diacetate (cFDA) used as substrate of the reaction. Esterase activity was expressed as nmol cF/min/mg of powder. Specific activity of enzyme preparations was determined. All enzyme preparations have shown β-glucosidase activity ranging from 20 to 900 nmol 4-MU/min/mg of powder. Four enzyme preparations defined for aroma release and 1 enzyme preparation defined for extraction and clarification have shown the highest values of specific β-glucosidase activity. These enzyme preparations are of interest for the enhancement of wine flavour through the hydrolysis of glycosidic precursors of grape. All enzyme preparations have shown esterase activity ranging from 10 to 100 nmol cF/min/mg of powder. The lowest level of specific esterase activity were showed by 5 enzyme preparations for extraction and clarification, 3 enzyme preparations for aroma release and 1 enzyme preparations for filtration. These enzyme preparations can be used without the risk of decrease of esters produced by yeast during fermetation. The proposed fluorimetric methods for both -glucosidase and esterase activity assay are very efficient and suitable for routine analyses.
b-glucosidase and esterase activities of commercial enzyme preparations used in winemaking / G. Fia; C. Dinnella; I. Rosi. - STAMPA. - (2011), pp. 105-106. (Intervento presentato al convegno Proceedings of the Wine Active Compounds 2011 International Conference tenutosi a Beaune, France nel 24-26 March 2011).
b-glucosidase and esterase activities of commercial enzyme preparations used in winemaking
FIA, GIOVANNA
;DINNELLA, CATERINA;ROSI, IOLANDA
2011
Abstract
Commercial enzyme preparations are used in winemaking to facilitate filtration, clarification and/or to release varietal aromas. -glucosidase activity of the enzyme preparations is involved in the hydrolysis of several compounds for the development of varietal wine flavour. On the other hands, esterase activity is involved in the hydrolysis of esters. Esters are an important group of volatile compounds produced by yeast during alcoholic fermentation. The aim of this study was to evaluate β-glucosidase and esterase activity of 17 commercial enzyme preparations. Commercial enzyme preparations were defined by the manufacturers for different technological applications (aroma release, extraction, clarification, filtration). β-glucosidase and esterase activity both by means of a fluorimetric micro-plate assay was determined. β-glucosidase activity was measured as the amount of 4-methylumbelliferone (4-MU) released from 4-methylumbelliferyl--D-glucopyranoside (4-MUG) used as substrate of the reaction. β-glucosidase activity was expressed as nmol 4-MU/min/mg of powder. Esterase activity was measured as the amount of 5(6)-carboxifluorescein (cF) released from 5(6)-carboxifluorescein diacetate (cFDA) used as substrate of the reaction. Esterase activity was expressed as nmol cF/min/mg of powder. Specific activity of enzyme preparations was determined. All enzyme preparations have shown β-glucosidase activity ranging from 20 to 900 nmol 4-MU/min/mg of powder. Four enzyme preparations defined for aroma release and 1 enzyme preparation defined for extraction and clarification have shown the highest values of specific β-glucosidase activity. These enzyme preparations are of interest for the enhancement of wine flavour through the hydrolysis of glycosidic precursors of grape. All enzyme preparations have shown esterase activity ranging from 10 to 100 nmol cF/min/mg of powder. The lowest level of specific esterase activity were showed by 5 enzyme preparations for extraction and clarification, 3 enzyme preparations for aroma release and 1 enzyme preparations for filtration. These enzyme preparations can be used without the risk of decrease of esters produced by yeast during fermetation. The proposed fluorimetric methods for both -glucosidase and esterase activity assay are very efficient and suitable for routine analyses.
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