Quality and Safety of Wine during Storage: Packaging and Stopper

Poor packaging often affects the quality and safety indicators of wine during storage. The need to preserve and prolong wine stability during long-term storage requires a comprehensive study of processes that occur in wines packaged and capped in various ways. This research featured 56 samples of white and red dry wines, which were bottled in four types of packages and stopper for 18 months. The effect of synthetic and natural stopper methods involved a model system that simulated the main composition of wine in line with the EAEU standards. The contents of free SO2 and dissolved oxygen, as well as the microbiology of natural corks, were studied using standard methods. The analysis of volatile substances relied on gas chromatography, mass spectrometry, and solid phase micro-extraction. The study recorded critical changes in the quality of wine products, characterized by increased oxidation markers and low free sulfur dioxide, which fell below 10 mg/dm3. In polyethylene terephthalate bottles, these changes occurred after 12 months of storage, while it took them 18 months to develop in multilayer bags and combined packaging materials. The components of natural and artificial plugs of microbial and chemical origin entered the model systems after 10 days of contact. The microbiological contamination was twice as high as the permissible level. The migration of microbial and chemical substances into the wine samples spoiled their quality and safety. The effect of packaging on the oxidative processes in white and red dry wines during storage resulted in different concentrations of dissolved oxygen and sulfur dioxide. The results can help wine producers to choose the most appropriate packaging and stopper means depending on the wine sort and its subsequent storage conditions. Alternative types of packaging proved to have a limited shelf life.