Repositori URV

Identifier: TDX:446

Handle: https://hdl.handle.net/20.500.11797/TDX446

Authors:
Labbé Pino, Mariela Alejandra

Abstract:
This thesis has been divided into three main subjects. The first focuses on how different storage conditions over a year affect the physical and chemical properties of commercial vinegars. The second deals with the aging of model vinegar solutions and wine vinegars by oak chips, with the purpose of understanding the evolution of color and the extraction of polyphenols from wood. The third studies lead reduction at trace levels in model vinegar solutions and commercial wine vinegars using a batch and continuous cation exchange resin. Three wine vinegars Chardonnay, Cabernet Sauvignon and Muscat and one apple vinegar were chosen to study the effect of different storage conditions. For one year various physical and chemical parameters were studied and only at the beginning and the end of this period were the phenolic and furanic compounds quantified. The Muscat wine and apple vinegars showed significant browning when temperature was increased. The total polyphenol content remained stable, except in those vinegars stored at high temperature, largely because of the increase in furanic compounds. American and French oak chips were used to study the aging of two model vinegar solutions (with and without added sugar), one sparkling-wine vinegar (without sugar addition) and one white-wine vinegar (with added sugar). The model vinegar solutions were aged for 448 days and the wine vinegars for 192 days. The total polyphenol content, phenolic profile and color were studied by CIELab coordinates. The evolution of the chromatic characteristics in model solutions and wine vinegars were not affected by the sugar concentration and all the vinegars showed similar behavior over time. The total polyphenol extraction in model vinegar solutions was higher when French oak chips were used and