AIM: Wine oxidation phenomena during the different processes of winemaking, aging and storage are closely related to the presence of oxygen and to the wine’s capacity for consumption. Grape composition will be directly related to wine composition, defining the O2 consumption rate, with particular importance of phenolic compounds and metal ions content. The prediction of the O2 consumption capacity of a wine could be a great tool to help in decision making during the winemaking process. The objetive of this work was the optimization of the reactivation of phenolic and aromatic fractions of grapes (PAFs) for the study of their avidity to consume oxygen. Beside, the effect of alcohol, pH, acetaldehyde and the metals Fe, Cu and Mn has been studied.
METHODS: Different PAFs reactivated under 16 different conditions defined by different levels of pH, alcohol content, acetaldehyde, iron, Cu and Mn were subjected to an oxygen consumption kinetic after saturation with air (1,2).
RESULTS: The parameters defining the kinetics of consumption allowed us to differentiate the different types of grapes. The greatest discriminatory capacity were the parameters related to the amount of oxygen consumed and the time invested in consuming this amount of oxygen, especially in the first stages or the time required to consume the 10% available oxygen, the area under the curve or the time to reach half-area. Thus, the lower iron content facilitated oxygen consumption, requiring less time, and similar results were found with respect to the presence of Mn.
CONCLUSIONS: The best activation conditions of phenolic and aromatic fractions have been established for the evaluation of different PAFs by developing their oxygen consumption kinetics.
Funding: This study was financed by MINECO (AGL2017-87373-C3-2- R t, M.C.Q pre-doctoral grant from Conicyt, Chile and R.S.G. post-doctoral contract from Junta de Castilla y León.
Authors: Marioli Alejandra, Carrasco-Quiroz – Dpt. Química Analítica, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain,Rosario, SANCHEZ-GOMEZ Dpt. Química Analítica, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain Ignacio NEVARES, Dpt. Ingeniería Agrícola y Forestal, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain Ana MARTINEZ-GIL Dpt. Química Analítica, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain María Del ALAMO-SANZA, Dpt. Química Analítica, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain
Email: maria.alamo.sanza@uva.es
Keywords: PAFs, activation factors, oxygen consumption kinetics parameters, oenological parameters
