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Helena Pereira - One of the best experts on this subject based on the ideXlab platform.
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Production of Cork Stoppers and discs
Cork, 2020Co-Authors: Helena PereiraAbstract:Cork is an industrial raw material that supports an integrated chain from production to the consumer, with an important impact at economic, social, and environmental levels in the corresponding regions of production and transformation. The industrial production is organized following two streamlines: (1) the production of Stoppers of natural Cork and the production of discs of natural Cork and (2) the production of agglomerates of Cork particles, with or without the addition of binding materials. This chapter presents an overview of the industrial organization in terms of these two processing lines by separating raw materials and product outputs. The production of Stoppers and Cork discs is described from the yard storage to the finishing operations. The operation of Cork boiling in water is also explained, highlighting its recent evolution. The evolution of Cork washing and bleaching and Cork quality classification are then presented. Finally, the yields and the quality profiles obtained in the production of Cork Stoppers and discs are presented.
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classification modeling based on surface porosity for the grading of natural Cork Stoppers for quality wines
Food and Bioproducts Processing, 2015Co-Authors: Vanda Oliveira, Sofia Knapic, Helena PereiraAbstract:Abstract The natural Cork Stoppers are commercially graded into quality classes according with the homogeneity of the external surface. The underlying criteria for this classification are subjective without quantified criteria and standards defined by Cork industry or consumers. Image analysis was applied to premium, good and standard quality classes to characterize the surface of the Cork Stoppers and stepwise discriminant analysis (SDA) was used to build predictive classification models. The final goal is to analyze the contribution of each porosity feature and propose an algorithm for Cork Stoppers quality class classification. This study provides the knowledge based on a large sampling to an accurate grading of natural Cork Stoppers. In average all the models presented accuracy in relation to the commercial classification over 68% with a higher mismatch in the mid-quality range. Color showed an important discriminating power, increasing the accuracy in 10%. The main discriminant features were porosity coefficient and color variables, calculated for the lateral surface. A quality classification algorithm was presented based on a simplified model with an accuracy of 75%. The classification based on color vision systems can ensure improved quality class uniformity and a higher transparency in trade.
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kinetics of oxygen ingress into wine bottles closed with natural Cork Stoppers of different qualities
American Journal of Enology and Viticulture, 2013Co-Authors: Vanda Oliveira, Paulo Lopes, Miguel Cabral, Helena PereiraAbstract:The kinetics of oxygen ingress into bottles closed with natural Cork Stoppers was investigated by a nondestructive colorimetric measurement method using the oxidation of an indigo carmine solution. In order to encompass the natural variability of Cork regarding its oxygen ingress into the bottle, 600 natural Cork Stoppers from different quality classes and produced from Cork planks of different calipers were analyzed. The kinetics of oxygen transfer was similar in all cases and could be adjusted to logarithmic models. A significant variability was found for oxygen ingress into the bottles closed with natural Cork Stoppers: ingress at 12 months ranged from 0.3 to 4.8 mg; 21% of the Stoppers reached the limit of oxygen quantification along the experiment. The results suggest that the variation of oxygen ingress is a consequence of the natural differing features in the cell dimensions and air volume within the stopper’s structure.
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natural variability of surface porosity of wine Cork Stoppers of different commercial classes
OENO One, 2012Co-Authors: Vanda Oliveira, Sofia Knapic, Helena PereiraAbstract:Aim : The aim of this study was to characterize the variability and to quantify the surface porosity of wine Cork Stoppers of different quality classes. Methods and results : The porosity of 300 Cork Stoppers was characterized by image analysis on the lateral surface and tops. Porosity coefficient was 2.4%, 4.0% and 5.5% for premium, good and standard Stoppers, respectively. The lateral surface of Stoppers was heterogeneous with respect to porosity features: the tangential regions presented higher porosity while the radial regions had larger pores. Conclusion : The quality classes of Cork Stoppers can be differentiated by the mean values of the main porosity features of their surface. There is a natural heterogeneity of the porosity features over the external surface of Cork Stoppers that can be traced back to the biological basis of Cork formation and the production process. Significance and impact of the study : Natural Cork Stoppers are the premium product of the Cork industry, with worldwide recognition of quality and performance as wine sealant. Due to the large sampling and detailed observation, the results presented in this study may be used for reinforcing quality requirements, e.g., with definition of standards to improve the classification system. A better understanding of Cork intrinsic variability and of the anisotropy of porosity features shown by Cork Stoppers is important for performance development.
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influence of cutting direction of Cork planks on the quality and porosity characteristics of natural Cork Stoppers
Forest Systems, 2010Co-Authors: Augusta Costa, Helena PereiraAbstract:In the industrial production of natural Cork Stoppers, Cork planks are cut transversely into strips and Stoppers are bored in the axial direction, therefore with their cylinder axis parallel to the tree axial direction. The influence of cutting direction of Cork planks (transverse or longitudinal), and therefore the orientation of Stoppers cylindrical axis (longitudinal or tangential, respectively) on yields, quality profile and porosity characteristics was studied in a random sampling of planks of different quality classes that were bored to produce 45 mm × 24 mm Stoppers. The Stoppers quality profile and production values were not influenced by the cutting direction, although in good quality planks (1st/2nd) the longitudinal cut led to a higher proportion of good quality Stoppers in comparison to the transversal cut, 32% vs. 23%. Regarding porosity characteristics, pore orientation differed between the two cutting directions but not the porosity coefficient, with the exception of the poor quality classes.
Xavier Gabarrell - One of the best experts on this subject based on the ideXlab platform.
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environmental analysis of the production of champagne Cork Stoppers
Journal of Cleaner Production, 2012Co-Authors: Jesus Rives, Ivan Fernandezrodriguez, Joan Rieradevall, Xavier GabarrellAbstract:Abstract Champagne Cork Stoppers are a product made basically from Cork, a natural and renewable resource extracted from Cork oak forests in western Mediterranean regions. Each stopper is made up of an agglomerated Cork body and two natural Cork discs. In 2009, 60% of the world’s champagne Cork Stoppers were produced in Catalonia, due to the importance of cava, champagne and other sparkling wines in neighbouring areas. The aim of this research was to provide environmental reference data on champagne Cork Stoppers production, and identify the industrial stages and operations that made the greatest impact. This research was carried out using life cycle assessment (LCA) methodology, and five of the most representative producers were analysed. The system considered all the processes involved in production after the forest management stage and one million champagne Cork Stoppers were taken as a functional unit (FU). Results showed that 53,886 kg of CO2 eq. were emitted to produce the FU. It was observed that the champagne Cork stopper manufacture stage represented between 57 and 67% of the environmental impact, depending on the category. Specifically, between 25 and 47% of the environmental impacts associated with this stage were caused by the body agglomeration operation, and between 21 and 29% were caused by the gluing of discs. On the other hand, some of the production stages such as the transport of raw Cork and intermediate products, Cork slab preparation or end of life stages represented a very small part of the total environmental impact of the product, less than 2%. Furthermore, it was observed that a champagne Cork stopper produced by the most impacting company presented a higher impact, between 10 and 27% above the sector average, depending on the impact category; while the least impacting company presented between 12 and 32% less impact. These differences indicate that some companies can improve their production by adopting technology and production practices that some of their competitors have already put in place.
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environmental analysis of the production of natural Cork Stoppers in southern europe catalonia spain
Journal of Cleaner Production, 2011Co-Authors: Jesus Rives, Ivan Fernandezrodriguez, Joan Rieradevall, Xavier GabarrellAbstract:Abstract The wine industry has developed greatly over recent years, and it could be stated that what was once a traditional industry has become a very productive and technical sector. One aspect that has not been studied until now is the Cork stopper, despite the fact that most wine bottles are sealed with this product, and practically all Corks are produced in the Iberian Peninsula. This study presents the environmental analysis of the production of natural Cork Stoppers, using life cycle assessment (LCA) methodology. The research was supported by data from four Catalan representative companies and all the stages involved in the production after the forest management have been taken into account. The purpose of this research was to provide reference data for the Catalan Cork industrial sector (Northeast Spain), and also contribute to deciding which aspects of natural Cork stopper production must be improved and further researched. Another objective of this research was to emphasise and demonstrate that LCA methodology could be an interesting tool for improving traditional industry, from a cleaner production perspective. Results could be used by other sector companies to analyse and compare themselves with in order to know if they could improve their production with the current available technology. Impact assessment results indicate that the manufacturing stage was the stage causing the greatest impact, but also an evaluation of the influence of the initial transport from the forest reveals that this stage could notably increase the impact when raw Cork was moved from distant forests.
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Environmental analysis of the production of natural Cork Stoppers in southern Europe (Catalonia – Spain)
Journal of Cleaner Production, 2010Co-Authors: Jesus Rives, Joan Rieradevall, Ivan Fernandez-rodriguez, Xavier GabarrellAbstract:Abstract The wine industry has developed greatly over recent years, and it could be stated that what was once a traditional industry has become a very productive and technical sector. One aspect that has not been studied until now is the Cork stopper, despite the fact that most wine bottles are sealed with this product, and practically all Corks are produced in the Iberian Peninsula. This study presents the environmental analysis of the production of natural Cork Stoppers, using life cycle assessment (LCA) methodology. The research was supported by data from four Catalan representative companies and all the stages involved in the production after the forest management have been taken into account. The purpose of this research was to provide reference data for the Catalan Cork industrial sector (Northeast Spain), and also contribute to deciding which aspects of natural Cork stopper production must be improved and further researched. Another objective of this research was to emphasise and demonstrate that LCA methodology could be an interesting tool for improving traditional industry, from a cleaner production perspective. Results could be used by other sector companies to analyse and compare themselves with in order to know if they could improve their production with the current available technology. Impact assessment results indicate that the manufacturing stage was the stage causing the greatest impact, but also an evaluation of the influence of the initial transport from the forest reveals that this stage could notably increase the impact when raw Cork was moved from distant forests.
J R Gonzalezadrados - One of the best experts on this subject based on the ideXlab platform.
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application of vis nir spectroscopy for estimating chemical physical and mechanical properties of Cork Stoppers
Wood Science and Technology, 2014Co-Authors: Cristina Prades, Florentino Gonzalezhernandez, Isabel Gomezsanchez, Juan Garciaolmo, J R GonzalezadradosAbstract:The aim of this study was to evaluate the potential of visible and near infrared spectroscopy (Vis/NIRS) in predicting the chemical, physical and mechanical behavior of single-piece natural Corks Stoppers used for sealing wine bottles. Two training sets of 90 and 150 Cork Stoppers were used to obtain four spectra per sample in different positions: two of the stopper bases (transversal section) and two of the stopper sides (tangential section and radial section). The samples were scanned in the range of 400–2,500 nm using a Foss-NIRSystems 6500 SY II spectrophotometer equipped with a remote reflectance fiber-optic probe. On each training set, two-thirds of the samples were used to develop modified partial least square (MPLS) calibration equations, and the remaining one-third of the sample for the external validation of these MPLS equations. The best equations were obtained for the transversal section, which is the recommended one when applying Vis/NIRS technology to Cork. The best results for the chemical composition were obtained for waxes and total polyphenols, showing coefficient of determination of the cross validation (r cv 2 ) values of 0.64 and 0.56 and coefficient of determination of the external validation (r EV 2 ) values of 0.53 and 0.55, respectively. The best equation for the physical and mechanical parameters was obtained for moisture content (r cv 2 = 0.86 and r EV 2 = 0.85), with somewhat lower results for density, compression force and extraction force (r cv 2 = 0.66, 0.72, 0.52 and r EV 2 = 0.52, 0.49, 0.51, respectively). The SECV (standard error of cross validation) and SEP (standard error of external validation) were similar for all the physical and mechanical parameters, thus confirming the robustness of the equations. MPLS model for moisture content fulfills the requirements for screening (RPD >2.5), but MPLS models obtained for waxes, total polyphenols, density, compression force and extraction force are not good enough for routine analysis or quality control. The results obtained from the MPLS models based on Vis/NIRS technology would permit the continuous quality control of humidity in the production line as well as obtaining information about certain chemical components (extractives contents) and some physical and mechanical parameters (density, extraction force and compression force).
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quality grading of Cork Stoppers based on porosity density and elasticity
European Journal of Wood and Wood Products, 2014Co-Authors: Florentino Gonzalezhernandez, J R Gonzalezadrados, J Garcia L De Ceca, Mariola SanchezgonzalezAbstract:An objective control method for grading Cork Stoppers is presented using a Cork stopper quality index based on porosity, density and elasticity, these being the properties which have the greatest influence on the closure capacity of the stopper. The elasticity of the Cork stopper is measured through the relaxation ratio, which is defined by the relationship between the relaxation force exerted by the Cork in the bottleneck and the compressive force exerted by a caliper to fit the stopper in the bottle. The relaxation ratio, defined in this way, represents the part of the compression force which is applied to the stopper on insertion and which is recovered in the form of the relaxation force to achieve closure. The calculation of the relaxation ratio involves the measurement of the relaxation force of the fitted stopper. This force has been measured rigorously and precisely using a device developed in the Cork Laboratory at the INIA-CIFOR and which is presented for the first time in this paper.
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control by atr ftir of surface treatment of Cork Stoppers and its effect on their mechanical performance
Wood Science and Technology, 2012Co-Authors: J R Gonzalezadrados, Florentino Gonzalezhernandez, J Garcia L De Ceca, Maria C Garciavallejo, Maria J Caceresesteban, Rosa CalvoharoAbstract:Fourier transform infrared (FTIR) spectroscopy was applied to determine the type of surface treatment and dose used on Cork Stoppers and to predict the friction between stopper and bottleneck. Agglomerated Cork Stoppers were finished with two different doses and using two surface treatments: P (paraffin and silicone), 15 and 25 mg/stopper, and S (only silicone), 10 and 15 mg/stopper. FTIR spectra were recorded at five points for each stopper by attenuated total reflectance (ATR). Absorbances at 1,010, 2,916, and 2,963 cm−1 were obtained in each spectrum. Discriminant analysis techniques allowed the treatment, and dose applied to each stopper to be identified from the absorbance values. 91.2% success rates were obtained from individual values and 96.0% from the mean values of each stopper. Spectrometric data also allowed treatment homogeneity to be determined on the stopper surface, and a multiple regression model was used to predict the friction index (If = Fe/Fc) (R 2 = 0.93).
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discriminant analysis of geographical origin of Cork planks and Stoppers by near infrared spectroscopy
Journal of Wood Chemistry and Technology, 2012Co-Authors: Cristina Prades, Isabel Gomezsanchez, Juan Garciaolmo, J R GonzalezadradosAbstract:Abstract The objective of this study was to assess the potential of visible and near infrared spectroscopy (VIS+NIRS) combined with multivariate analysis for identifying the geographical origin of Cork. The study was carried out on Cork planks and natural Cork Stoppers from the most representative Cork-producing areas in the world. Two training sets of international and national Cork planks were studied. The first set comprised a total of 479 samples from Morocco, Portugal, and Spain, while the second set comprised a total of 179 samples from the Spanish regions of Andalusia, Catalonia, and Extremadura. A training set of 90 Cork Stoppers from Andalusia and Catalonia was also studied. Original spectroscopic data were obtained for the transverse sections of the Cork planks and for the body and top of the Cork Stoppers by means of a 6500 Foss-NIRSystems SY II spectrophotometer using a fiber optic probe. Remote reflectance was employed in the wavelength range of 400 to 2500 nm. After analyzing the spectroscop...
Carlos Pinho - One of the best experts on this subject based on the ideXlab platform.
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PRESSURE DROP IN A SPOUTED BED OF Cork Stoppers
Revista de Engenharia Térmica, 2018Co-Authors: Ana Magalhaes, Carlos PinhoAbstract:The spouted bed is a particular type of fluidized bed which is well suited for the handling of large size particles like Cork Stoppers. It is commonly used for the drying of granulates and the present work is the first part of a study concerning the drying of Cork Stoppers in a laboratory scale spouted bed reactor. The study considers two Stoppers size, one the port wine stopper and another small size stopper. The choice of these smaller sizes was imposed by the small dimensions of the reactor. In this preliminary set of experiments the fluid-dynamics regime of the particular two phase flow was characterized. For different experimental situations covering several air flows and temperatures typical of Cork drying operations the evolution of pressure drop was evaluated and a correlation for the minimum spouting velocity was obtained.
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spouted bed drying of Cork Stoppers
Chemical Engineering and Processing, 2008Co-Authors: Ana Magalhaes, Carlos PinhoAbstract:Abstract The spouted bed is commonly used to dry granular particles as it displays some special characteristics which render it capable of performing cyclic operations, with particles that are very difficult to fluidize under a different type of bed. Information on the characteristic drying rates of Cork Stoppers is still very limited in the technical and scientific literature, and until now no published data was found on the spouted bed drying of Cork Stoppers. The characterization of the drying performance of Port wine Cork Stoppers was carried out in a laboratory scale spouted bed. Characteristic drying curves were determined with 29 mm × 21 mm Cork Stoppers under several operating conditions. Values for the effective diffusivity were obtained in the range of 1.36 × 10−9 to 4.44 × 10−9 m2/s, with the temperature dependence represented by an Arrhenius-type relationship. The activation energy obtained was 28.72 kJ/mol.
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DILUTE PHASE VERTICAL PNEUMATIC CONVEYING OF Cork Stoppers
Revista de Engenharia Térmica, 2006Co-Authors: R. Barbosa, Carlos PinhoAbstract:The pneumatic conveying of Cork Stoppers is used in the Cork processing industries with equipments designed and built purely on an empirical basis. Experimental studies to characterize this type of pneumatic transportation have been, so far, oriented towards the study of horizontal conveying processes, either for steady state transportation or for the acceleration zone. However studies were carried out on the determination of the pressure drop on vertical transportation of Cork Stoppers. Here the experimental apparatus and procedure are described, and the first experimental data that have been obtained are shown. In consequence a simple correlation for the pressure drop in the steady state region of the conveying pipe is proposed. The correlation is a function of dimensionless parameters used to characterize the two phase flow under analysis. Three standard Stoppers sizes and a single pipe diameter were used in the experiments, all carried out at ambient temperature.
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pressure drop in packed shallow beds of cylindrical Cork Stoppers
Chemical Engineering Research & Design, 2001Co-Authors: N Rangel, A Santos, Carlos PinhoAbstract:The pressure drop through a packed bed of solid particles has been thoroughly studied and equations relating the pressure drop and the fiow rate of the fiuid were developed by many authors, mainly for relatively deep bed conditions. On the contrary, pressure drop evolution in shallow packed beds of cylindrical particles is still being studied, and standard equations for fixed beds are applicable to this situation only with gross limitations. The study and characterisation of air fiow through packed shallow beds of Cork Stoppers was carried out and consequently a simple analysis was developed and correlations obtained from experimental data.
Enriqueta Antico - One of the best experts on this subject based on the ideXlab platform.
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multivariate analysis of volatile compounds detected by headspace solid phase microextraction gas chromatography a tool for sensory classification of Cork Stoppers
Food Chemistry, 2011Co-Authors: Chantal Prat, Emili Besalu, Lluis Baneras, Enriqueta AnticoAbstract:The volatile fraction of aqueous Cork macerates of tainted and non-tainted agglomerate Cork Stoppers was analysed by headspace solid-phase microextraction (HS-SPME)/gas chromatography. Twenty compounds containing terpenoids, aliphatic alcohols, lignin-related compounds and others were selected and analysed in individual Corks. Cork Stoppers were previously classified in six different classes according to sensory descriptions including, 2,4,6-trichloroanisole taint and other frequent, non-characteristic odours found in Cork. A multivariate analysis of the chromatographic data of 20 selected chemical compounds using linear discriminant analysis models helped in the differentiation of the a priori made groups. The discriminant model selected five compounds as the best combination. Selected compounds appear in the model in the following order; 2,4,6 TCA, fenchyl alcohol, 1-octen-3-ol, benzyl alcohol and benzothiazole. Unfortunately, not all six a priori differentiated sensory classes were clearly discriminated in the model, probably indicating that no measurable differences exist in the chromatographic data for some categories. The predictive analyses of a refined model in which two sensory classes were fused together resulted in a good classification. Prediction rates of control (non-tainted), TCA, musty-earthy-vegetative, vegetative and chemical descriptions were 100%, 100%, 85%, 67.3% and 100%, respectively, when the modified model was used. The multivariate analysis of chromatographic data will help in the classification of Stoppers and provide a perfect complement to sensory analyses.
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Multivariate analysis of volatile compounds detected by headspace solid-phase microextraction/gas chromatography: A tool for sensory classification of Cork Stoppers.
Food Chemistry, 2010Co-Authors: Chantal Prat, Emili Besalu, Lluis Baneras, Enriqueta AnticoAbstract:The volatile fraction of aqueous Cork macerates of tainted and non-tainted agglomerate Cork Stoppers was analysed by headspace solid-phase microextraction (HS-SPME)/gas chromatography. Twenty compounds containing terpenoids, aliphatic alcohols, lignin-related compounds and others were selected and analysed in individual Corks. Cork Stoppers were previously classified in six different classes according to sensory descriptions including, 2,4,6-trichloroanisole taint and other frequent, non-characteristic odours found in Cork. A multivariate analysis of the chromatographic data of 20 selected chemical compounds using linear discriminant analysis models helped in the differentiation of the a priori made groups. The discriminant model selected five compounds as the best combination. Selected compounds appear in the model in the following order; 2,4,6 TCA, fenchyl alcohol, 1-octen-3-ol, benzyl alcohol and benzothiazole. Unfortunately, not all six a priori differentiated sensory classes were clearly discriminated in the model, probably indicating that no measurable differences exist in the chromatographic data for some categories. The predictive analyses of a refined model in which two sensory classes were fused together resulted in a good classification. Prediction rates of control (non-tainted), TCA, musty-earthy-vegetative, vegetative and chemical descriptions were 100%, 100%, 85%, 67.3% and 100%, respectively, when the modified model was used. The multivariate analysis of chromatographic data will help in the classification of Stoppers and provide a perfect complement to sensory analyses.
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Molecular Fingerprinting by PCR-Denaturing Gradient Gel Electrophoresis Reveals Differences in the Levels of Microbial Diversity for Musty-Earthy Tainted Corks
Applied and Environmental Microbiology, 2009Co-Authors: Chantal Prat, Enriqueta Antico, Olaya Ruiz-rueda, Rosalia Trias, Dimitra L. Capone, Mark A. Sefton, Lluis BanerasAbstract:The microbial community structure of Cork with marked musty-earthy aromas was analyzed using denaturing gradient gel electrophoresis of amplified ribosomal DNA. Cork Stoppers and discs were used for DNA extraction and were analyzed by using selective primers for bacteria and fungi. Stoppers clearly differed from discs harboring a different fungal community. Moreover, musty-earthy samples of both types were shown to have a specific microbiota. The fungi Penicillium glabrum and Neurospora spp. were present in all samples and were assumed to make only a small contribution to off-odor development. In contrast, Penicillium islandicum and Penicillium variabile were found almost exclusively in 2,4,6-trichloroanisole (TCA) tainted discs. Conversely, Rhodotorula minuta and Rhodotorula sloofiae were most common in Cork Stoppers, where only small amounts of TCA were detected. Alpha- and gammaproteobacteria were the most commonly found bacteria in either control or tainted Cork Stoppers. Specific Pseudomonas and Actinobacteria were detected in Stoppers with low amounts of TCA and 2-methoxy-3,5-dimethylpyrazine. These results are discussed in terms of biological degradation of taint compounds by specific microorganisms. Reliable and straightforward microbial identification methods based on a molecular approach provided useful data to determine and evaluate the risk of taint formation in Cork.
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Ethanol/Water Extraction Combined with Solid-Phase Extraction and Solid-Phase Microextraction Concentration for the Determination of Chlorophenols in Cork Stoppers
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Sara Insa, Victoria Salvado, Emili Besalu, Cristina Iglesias, Enriqueta AnticoAbstract:The appearance of 2,4,6-trichloroanisole (TCA) in Cork Stoppers is of great concern because it can cause off-flavors in bottled wine. To prevent this sensorial defect, there should not be any traces of 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), or pentachlorophenol (PCP) in the finished Corks, because they are the direct precursors of TCA. In the course of this study two methodologies based upon an extraction with ethanol/water mixtures to determine the chlorophenolic content in Cork matrices were developed. The Cork extract is preconcentrated using both solid-phase extraction and solid-phase microextraction methodologies. The latter was optimized by applying a full two-level factorial design. Finally, spiked ground Corks at nanogram per gram levels of each chlorophenol were analyzed under optimal conditions and by applying both procedures. The obtained results demonstrate that chlorophenols can be detected in Corks contaminated at the nanogram per gram level and, thus, these approaches can be successfully applied as quality control measures in the Cork industry.
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ethanol water extraction combined with solid phase extraction and solid phase microextraction concentration for the determination of chlorophenols in Cork Stoppers
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Sara Insa, Victoria Salvado, Emili Besalu, Cristina Iglesias, Enriqueta AnticoAbstract:The appearance of 2,4,6-trichloroanisole (TCA) in Cork Stoppers is of great concern because it can cause off-flavors in bottled wine. To prevent this sensorial defect, there should not be any traces of 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), or pentachlorophenol (PCP) in the finished Corks, because they are the direct precursors of TCA. In the course of this study two methodologies based upon an extraction with ethanol/water mixtures to determine the chlorophenolic content in Cork matrices were developed. The Cork extract is preconcentrated using both solid-phase extraction and solid-phase microextraction methodologies. The latter was optimized by applying a full two-level factorial design. Finally, spiked ground Corks at nanogram per gram levels of each chlorophenol were analyzed under optimal conditions and by applying both procedures. The obtained results demonstrate that chlorophenols can be detected in Corks contaminated at the nanogram per gram level and, thus, these approaches can be successfully applied as quality control measures in the Cork industry.