Close this search box.

The bioabsorption of aromas in cork, an opportunity for the sector

The cork stopper is a high quality product and about 7 bottles out of every 10 that are corked around the world do so with a cork stopper. Acceptance and recognition of its quality by consumers is widespread in the main countries; even so the cork sector continues to work to alleviate one of the weak points of cork stoppers that is inherent in its natural origin and in its particular internal structure. Alternative stoppers or stoppers without cork (both synthetic and screw) have historically strengthened their position in the corking market by appealing to their absence of TCA.

Trichloroanisole (TCA) is a harmless molecule in terms of health, but it has the disadvantage that it is detectable by the human nose at a very low concentration (of the order of 3 parts per trillion in white wine and 8 parts per trillion in red wine or, what would come to be the same, the volume of TCA of a spoonful of coffee in an Olympic swimming pool) and that affect the final bouquet of the wine. This fact has led the cork sector to promote research and innovation for the development of new technologies for the detection and / or elimination of these aromatic compounds.

Most of the companies in the cork sector have systems for extracting and reducing / eliminating aromas present in the products that are obtained from the different stages of production of cork stoppers. Although the application of these new technologies has managed to considerably reduce the presence of sensory deviations associated with cork stoppers, the cork industry continues to bet on the continuous improvement of its technologies, in particular, due to the persistence of some of these compounds, as would be the case of the TCA. In addition, it must be borne in mind that it is not possible to apply intense treatments since the properties of cork depend largely on its cellular structure, which at the same time can be affected depending on the conditions to which this material is subjected.

It is for this reason that an operational group formed by five companies that manufacture cork stoppers from the Catalan cork sector, -Costa Quer SA, DE MARIA TAPS SL, J. VIGAS SA, TESA SA and FRANCISCO OLLER SA- is being set up to promote the project "Development of a system for the elimination of TCA in corks based on the use of adsorbents and biosorbents" with the objective of developing an innovative system for the elimination of aromas in corks that is based on the combination of different adsorbent materials and biosorbents These materials will be applied in the reduction systems that companies already have with the objective of increasing their efficiency without having to increase the values of the factors responsible for the reduction (temperature, pressure...).

Throughout the project, eight adsorbents / biosorbents have been evaluated to determine their reduction potential by haloanisoles (TCA, teak, TBA, PCA) and four have been selected, two suitable for application in cleaning and aroma extraction systems that they use water and, both suitable for their application in the environment. The selected materials are active carbons obtained from vegetable by-products such as coconut shells. At the laboratory scale, the selected materials have presented a haloanisole reduction percentage of 69.5% to 88.4% in the case of adsorbents applied in a liquid medium and, from 40 to 96% in the case of adsorbents applied in a gaseous medium.

The next step was the design of two versatile prototypes that contain the materials and can be installed in the different reduction systems present in companies. Currently, its efficiency in reducing these aromas is being validated based on the analysis of cork samples before and after passing through the system and the environment where they are applied. Finally, the adsorbents / biosorbents used must be analyzed to determine the useful life of this material.

With this project it is intended to have two prototypes destined to increase the efficiency of the systems for reducing organoleptic deviations that companies already have in order to give an impetus and increase the competitiveness of their products with respect to alternative caps, given that these are the who defend its use against the natural plug ensuring the absence of deviations. However, the cork industry is where more resources are being allocated, especially in innovation, and it is leading to a very different reality.

It is a project co-financed by the European fund FEDER and by the Department of Agriculture, Livestock, Fishing and Food of the Generalitat of Catalonia through Operation 16:01:01 (cooperation for innovation) of the PDR of Catalonia 2014-2020