Browning during biological aging and commercial storage of Cava sparkling wine and the use of 5-HMF as a quality marker

- Browning (A420) increases over time in biological aging and in commercial storage.
- No differences were found between the kinetics of the two aging types.
- Total phenol content does not change, though some phenolics evolve with aging time.
- 5-HMF was correlated with time and browning, showing marker abilities.
- 5-HMF discriminates better than A420 between quality categories (biological aging).

The quality of sparkling wines can deteriorate due to browning, which is mainly attributed to the oxidation of phenols. The aim of this study was to assess the browning (measured as the absorbance at 420 nm) of two real series of Cava sparkling wines (A and B) during aging sur lie (biological aging, with lees) and commercial storage (without lees) under real conditions, over almost two years, since lees may reduce the effect by adsorbing the precursors and the browning compounds. The role of phenolics and 5-HMF (5-hydroxymethylfurfural) was also assessed. A significant linear increment in browning was observed in all four Cava series in both kinds of aging. No differences in browning were observed between the two types of aging (biological vs. commercial storage). In contrast, the 5-HMF content increased linearly with time although its rate of formation was dependent on the type of aging (biological or storage). The phenolic compounds trans-coutaric and p-coumaric increased significantly with time and were significantly correlated with browning. The most aged sparkling wines (Gran Reserva) had highest A420 and 5-HMF values. 5-HMF was correlated with browning and can be used as a quality marker.