Prevention of browning development in white wine by Se addition

Abstract

Oxidation of white wines implies modification of their organoleptic characteristics and in most cases degradation of their overall quality. The development of oxidative browning is associated with polyphenol oxidation, and it can be accelerated by the presence of metal ions such as Fe2+ while it may be delayed by the addition of antioxidants, such as selenium (Se) and SO2. The aim of this study was to study the browning capacity of Assyrtiko white wines after Se addition at two temperatures (35 and 50°C) employing the accelerated browning test. For this purpose, two concentrations of Se were added at the wine, either alone or with the simultaneous presence of Fe2+, and the absorbance at 420 nm was monitored for twelve days. It was also of interest to evaluate the changes of other analytical parameters which are implicated in wine oxidation such as: SO2 content (free and total). Browning was approached from a kinetic point of view and the study was focused on the implication of oxidants and antioxidants on browning rate. The results showed that the addition of Se protected wine color and preserved total SO2 at 35°C while at 50°C these effects were not any longer observed. GSH content of the samples containing Se after 12 days of accelerated ageing was similar with that of the control.