RT Journal Article
SR Electronic
T1 Press Fractioning of Grape Juice: A First Step to Manage Potential Atypical Aging Development during Winemaking
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP ajev.2019.19030
DO 10.5344/ajev.2019.19030
A1 Tomas Roman
A1 Tiziana Nardin
A1 Gianmaria Trenti
A1 Chiara Barnaba
A1 Giorgio Nicolini
A1 Roberto Larcher
YR 2019
UL http://www.ajevonline.org/content/early/2019/09/12/ajev.2019.19030.abstract
AB The development in young white wines of 2-aminoacetophenone, commonly known as atypical aging defect (UTA), leads to unpleasant notes such as mothball, wet mop, sweaty, acacia blossom or soap. Tryptophan and indole-3-acetic acid, the auxin most present in plants, are considered the main precursors of this compound. Also indole-3-acetonitrile, indole-3-lactic acid, skatole, tryptophol and the inactivated form of the auxin, N-(3-indolylacetyl)-L-alanine, N-(3-indolylacetyl)-DL-aspartic acid and methyl-indole-3-acetate, can act as potential precursors of 2-aminoacetophenone and directly contribute to UTA scents in wines.This paper investigates the distribution of 2-aminoacetophenone precursors or intermediate metabolites (n=9) in grape berry tissues (pulp, skin and seeds) in 12 samples of 4 different varieties (Cabernet Cantor, Chardonnay, Merlot, and Solaris). The issue regarding Chardonnay (3 lots) was analyzed more in depth by evaluating the precursor extraction of industrial pressing at different stages. For the quantification, this study developed and validated a high performance liquid chromatography coupled with a high-resolution mass spectrometry method. Owing to the use of a pre-concentration and purification SPE-online system, a detection limit was detected between 0.25 and 2 µg/L, depending on the compound. Despite significant varietal differences, the research showed that indole-3-acetic acid is more present in seeds and skin fractions. Indeed, only ~30% of the total berry amount were extracted with free run pressing, whereas ~80% were reached with 0.6 bar. This indicates a fundamental role of pressing in managing the development of UTA during winemaking.