Spectroscopy reveals that ethyl esters interact with proteins in wine.
Impairment of wine aroma after vinification is frequently associated to bentonite treatments and this can be the result of protein removal, as recently demonstrated for ethyl esters. To evaluate the existence of an interaction between wine proteins and ethyl esters, the effects induced by these fermentative aroma compounds on the secondary structure and stability of VVTL1, a Thaumatin-like protein purified from wine, was analyzed by Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The secondary structure of wine VVTL1 was not strongly affected by the presence of selected ethyl esters. In contrast, VVTL1 stability was slightly increased by the addition of ethyl-octanoate, -decanoate and -dodecanoate, but decreased by ethyl-hexanoate. This indicates the existence of an interaction between VVTL1 and at least some aroma compounds produced during fermentation. The data suggest that proteins removal from wine by bentonite can result in indirect removal of at least some aroma compounds associated with them.
Department of Land, Environment, Agriculture and Forestry (TESAf), University of Padua, Viale dell'Università, 16, 35020 Legnaro (PD), Italy. Electronic address: mattia.digaspero@studenti.unipd.it.
Mattia
M
Di Gaspero
Institute of Biomolecular Chemistry of CNR, Padua Unit, via Marzolo, 1, 35127 Padua, Italy.
Paolo
P
Ruzza
Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
Rohanah
R
Hussain
Department of Agronomy, Food, Natural Resources Animals and Environment (DAFNAE), University of Padua, Viale dell'Università, 16, 35020 Legnaro (PD), Italy.
Simone
S
Vincenzi
Institute of Biomolecular Chemistry of CNR, Padua Unit, via Marzolo, 1, 35127 Padua, Italy.
Barbara
B
Biondi
Department of Agronomy, Food, Natural Resources Animals and Environment (DAFNAE), University of Padua, Viale dell'Università, 16, 35020 Legnaro (PD), Italy.
Diana
D
Gazzola
Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
Giuliano
G
Siligardi
Department of Agronomy, Food, Natural Resources Animals and Environment (DAFNAE), University of Padua, Viale dell'Università, 16, 35020 Legnaro (PD), Italy.
Andrea
A
Curioni
D001546:Bentonite / Q000737:chemistry; D002942:Circular Dichroism; D004952:Esters / Q000737:chemistry*; D005285:Fermentation; D000067030:Fruit and Vegetable Juices / Q000032:analysis; D009812:Odorants; D010940:Plant Proteins / Q000737:chemistry*; D017356:Synchrotrons; D027843:Vitis / Q000737:chemistry; D014920:Wine / Q000032:analysis*
D004952:Esters; D010940:Plant Proteins; D001546:Bentonite
Aroma; Ethyl esters; Proteins; SRCD; Spectroscopy; VVTL1; Wine