With the aim of knowing the effect of the whole non-volatile wine matrix composition 26 on the volatility of typical wine aroma compounds, five types of wine matrices (young 27 white, young red, oak aged red, Cava sparkling and a sweet wine) representing a wide 28 range of wine compositions, were previously deodorized and reconstituted to the same 29 ethanol concentration and aromatized with a mixture of 36 aroma compounds at 5 levels 30 of concentration. Slopes of regression lines, obtained by solid phase microextraction-31 gas chromatography-mass spectrometry, were compared to the slopes calculated for the 32 same compounds in a control wine, with no matrix effect. The main observed effect was 33 a reduction in the slopes, or a retention effect, that was larger for the reconstituted 34 sparkling wine, which showed between 11% and 69% lower slopes than the control 35 wines for compounds such as ethyl hexanoate and octanoate and the terpenic compound 36 nerol. In addition, an increase in the slope, or a "salting out" effect in the most 37 compositional complex reconstituted aged-red and sweet wines was also noticed for 38 some volatiles (2-methylbutyrate, butyl and hexyl acetate, 5-methyl furfural) with very 39 low boiling point or low hydrophobic constant values. 40 41 42

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A reversed-phase high-performance liquid chromatography-fluorescence detection methodology involving a pre-column derivatization procedure using 2,3-naphtalenedialdehyde in the presence of 5 and 0.5 mM of dithiothreitol to determine total and reduced glutathione (GSH) and γ-glutamyl-cysteine (γ-glu-cys) in musts and wines has been set up and validated. The proposed method showed good linearity (R 2 >99% for reduced and total GSH, and R 2 >98% for γ-glu-cys) in synthetic wines, over a wide range of concentration (0-10 mg L −1 ). The limits of detection for reduced GSH in synthetic and real wines were almost the same (0.13 and 0.15 mg L −1 , respectively) and slightly higher for γ-glu-cys (0.24 mg L −1 ). The application of the method allowed knowing, for the first time, the amount of total and reduced GSH and γ-glu-cys released into synthetic wines by oenological preparations of commercial inactive dry yeast (IDY). In addition, the evolution of these three compounds during the winemaking and shelf life (0-9 months) of an industrially manufactured rosé wine supplemented with a GSH-enriched IDY showed that although GSH is effectively released from IDY, it is rapidly oxidized during alcoholic fermentation, contributing to the higher total GSH content determined in wines supplemented with GSH-enriched IDYs compared to control wines.