Cork-wine interaction studies: liquid absorption and non-volatile compound migration

Abstract

<p style="text-align: justify;"><strong>Aims</strong>: To provide a better knowledge of cork-wine interaction, focussing on absorption of liquid by the cork stopper and overall migration of non-volatile compounds from the cork-stopper to liquid.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Natural cork stoppers and 1+1 technical cork stoppers (agglomerate cork body ended with natural cork washers), with and without surface treatment, were used to close bottles filled with 12 % v/v ethanolic solution and removed after 3, 6, 12 and 24 months of contact. Mean and limit values of absorption and overall migration at each time are used to compare treated and non-treated stoppers. Variation of absorption with contact time was studied by adjusting the ABSORPTION = a · Ãt model (R2: 0.8572 - 0.9756).</p><p style="text-align: justify;"><strong>Conclusion</strong>: Most of the overall migration is due to natural components of cork. Contact time and type of cork stopper are the factors responsible for the greatest variability. Surface treatment increases overall migration (2 mg/stopper) and reduces liquid absorption (more than 10 %).</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The results show how a correct characterization of stopper and surface treatment is needed to predict the evolution of cork-wine interaction.</p>

Control by ATR-FTIR of surface treatment of cork stoppers and its effect on their mechanical performance

“…This improvement is due to the decrease in the wettability of the material, altered by the washing processes (Chatonnet and Labadie 2003;Fortes et al 2004). Thus, the surface treatment decreases the flow of liquid (percolation) between the stoppers and the bottleneck (Gonzalez-Adrados et al 2008). On the other hand, it may affect the air permeability, which is very important in the process of aging wine in the bottle (Kontoudakis et al 2008;Lopes et al 2007;Skouroumounis et al 2005), one of the most studied aspects in recent years.…”

Effects of Long-Term Bottle Storage on Red and Rosé Wines Sealed with Different Types of Closures

“…In addition, storage conditions such as temperature and light exposure in the cellar are also relevant to the maturation of wine [ 3 ], but not all of them can influence the different aspects of wine quality in the same way (for example, aroma and color profiles). Wine ageing in bottles can be impacted by the quality of the closure used [ 4 , 5 , 6 , 7 ], which can drastically affect the commercial quality of the product, consumer preferences and, in general, the reputation of the winery. For example, a natural one-piece cork closure of low quality may be too permeable to air or may contract due to dehydration (due to a very low environmental relative humidity), leading to breakage of the closure, or to wine oxidation [ 8 , 9 , 10 , 11 , 12 ].…”

“…The effect of different closure materials on wine development has also been studied [ 6 , 28 , 29 , 30 , 31 , 32 ]. Godden et al [ 29 ] evaluated the performance of different closures (natural cork, technical cork, screw cap, and synthetic closures) on bottled wines after 20 months of storage.…”

“…The direct interactions of the closure with the wine has been an important subject of research. González-Adrados et al [ 6 ] conducted a study using two different closure materials (natural cork and 1 + 1 technical cork) with treated and non-treated surfaces to evaluate the interactions between the closure and the wine. Their results showed that most of the overall migration of non-volatile compounds from the closure to the wine was due to the natural components of the cork.…”

Variation in the Phenolic Composition of Cork Stoppers from Different Geographical Origins

“…Cork stoppers are known nowadays as a dynamic material interacting with the bottled solution. 1 The hypothesis of their influence in the evolution of bottled wine has been growing, based on the different evolution of the same batch of bottled wine as explained by the well-known variability of cork stoppers since they are produced by a random selection of cork planks from different trees and locations, and, in addition, by the extraction of compounds at a different extent promoted by the cork nature.…”