Use of Fe (II) and H2O2 along with Heating for the Estimation of the Browning Susceptibility of White Wine

The aim of the present study was to investigate if the use of Fe (II) and H2O2 (Fenton reaction) along with heating can be implicated for the rapid evaluation of the browning susceptibility of white wine. In this context, increasing concentrations of Fe (II) and H2O2 were added to two white wines (Roditis–Malagouzia and Debina), the samples were stored at 45 °C or 18 °C, and the absorbance at 420 nm (browning index) was measured. Moreover, total sulfur dioxide, total phenolics, flavanols, hydroxycinnamates and total free sulfhydryls were assessed during storage of Roditis–Malagouzia wine samples. The results showed that the addition of Fe (II) + H2O2 mixture in white wines increases rapidly the browning index at 45 °C, indicating the ability to develop a rapid test for the estimation of the browning susceptibility of white wines. Results also showed that the level of flavanols is a suitable index to follow the forced oxidative browning of white wine by adding Fe II + H2O2 at 45 °C. Moreover, results indicated that the levels of total free sulfhydryls may be a suitable index to follow the forced oxidative browning of white wine and in general, white wine oxidation.