Impact of high pressure treatments on the physicochemical properties of a sulphur dioxide-free white wine during bottle storage: Evidence for Mail lard reaction acceleration

The impact of high hydrostatic pressure (HHP) treatments on physicochemical characteristics of sulphur dioxide-free white wines was studied during one year of bottle storage. For this purpose, a white wine was produced without the addition of sulphur dioxide (SO2) and was pressurized at two pressure conditions, 500 and 425 MPa, for 5 min at 20 degrees C. A wine with 40 ppm of SO2 and a wine with no preservation treatment were used as controls. Pressurized wines showed, after one year of storage, a more brownish color (higher a* and b* values and lower L*) and a slightly lower antioxidant activity and total content of phenolic compounds compared to the unpressurized wines (wine with SO2 and wine without any treatment). These results, together with the lower content of free amino acids (e.g. 87% less of serine) and higher content of furans (e.g. 10 fold higher of 2-furfural), presented in the pressurized wines after nine months of storage, lead to propose an effect of HHP treatments in the acceleration of Maillard reactions occurring during the wine storage period. Industrial relevance: HHP might be used in winemaking as an alternative process for preservation of wine, which can lead to the production of a wine with reduced amounts of SO2. Until now, the physicochemical and sensorial properties of wine have been studied only after the pressure treatment, without ever having references on the influence of the treatment in wine properties during storage. Then, the effect of HHP on the physical-chemical characteristics on long term storage of wine is still largely unknown. This work shows that HHP treatments accelerate Maillard reactions during the white wine storage period. This reaction should be taken into consideration in the implementation of HHP treatments to wine conservation as alternative to SO2. (C) 2013 Elsevier Ltd. All rights reserved.