Modelling oxygen ingress through cork closures. Impact of test conditions

Oxygen permeability data is relevant for selecting wine bottles closures. Market available stoppers, two natural and eight microagglomerated corks, were analysed for the oxygen ingress over time in stoppered bottles, under different temperatures (8, 23, and 40 °C), with and without contact between cork and wine simulant. Weibull model described well the oxygen ingress. Differences were found between cork types in long-term oxygen pressure (Po) and ingress rates (τ). For microagglomerated corks, Po increased, and τ decreased with temperature, following the Arrhenius behaviour, with estimated activation energies of 15.3 and 35.2 kJ mol−1, respectively. Microagglomerated corks exhibited slower initial oxygen ingress but higher long-term oxygen ingress than natural corks. Principal Component Analysis (PCA) showed that factors related to the bottleneck-cork interface contributed more to the variance of the system than cork type. Liquid contact reduces oxygen ingress around five times. The temperature impact in the oxygen ingress was lower for natural corks.