不同种类葡萄酒软木塞的密封性能研究

对不同种类软木塞进行密封性能试验,并对封存的葡萄酒样品进行感官品评试验。结果表明,聚合塞适用于葡萄酒的短期储存;贴片1＋1塞适用于葡萄酒的中短期储存;天然软木塞适用于葡萄酒的长期储存。     

Migration of phenolic compounds from different cork stoppers to wine model solutions: antioxidant and biological relevance

Considering the enological interest of cork, this study aimed to identify and quantify the phenolic compounds able to migrate from different classes (natural cork stoppers “Flor” and “Third” quality and microagglomerate cork stopper) of cork stoppers into bottled wine model solutions. Another aim was to evaluate some antioxidant and biological features of cork phenolics that migrated into the wine model solutions. The main phenolic acids and aldehydes detected were as follows: gallic and protocatechuic acid detected both around 3.5 mg/L and vanillin and protocatechuic aldehyde detected around 2.5 and 1.5 mg/L after 27 months of bottling, respectively. Trace amounts of more complex polyphenols, namely hydrolysable tannins (castalagin/vescalagin and mongolicain A/B), were also detected. Two antioxidant features of the wine model solutions bottled with different wine cork stoppers were studied, namely the antiradical capacity and the reducing capacity, being the natural cork stoppers the ones with the higher activities. The intestinal absorption of the compounds in each wine model solution after 27 months in bottled was evaluated. The simpler phenolic compounds were able to cross Caco-2 cell model. The antiproliferative activity of the same wine model solutions was also evaluated against gastric and breast cancer cells. All samples were active against the two cell lines, which highlight the possible health outcomes of wine sealed with cork stoppers.     

Determination of Chloroanisoles and Chlorophenols in Cork and Wine by using HS‐SPME and GC‐ECD Detection

Cork taint is an off‐flavor problem in wine, the main reason being the presence of 2,4,6‐trichloroanisole (TCA) in the cork stopper. In addition to the TCA, the presence of other chloroanisole and chlorophenol family compounds (the perception limits of which are very low) can also result in, or contribute to, cork taint problem. In this study, the levels of 2,4‐dichloroanisole (DCA), 2,4,6‐trichloroanisole (TCA), 2,3,4,6‐tetrachloroanisole (TeCA), pentachloroanisole (PCA), 2,4,6‐trichlorophenol (TCP), 2,3,4,6‐tetrachlorophenol (TeCP) and penthaclorophenol (PCP) were assayed in cork stoppers (natural, agglomerated and colmate) and in red wine samples from different wineries in Turkey using HS‐SPME and GC‐ECD detection. The performance parameters for all chloroanisole and chlorophenol compounds were as follows: recovery 92.48–102.53%, R 0.992‐0.996. The LOQ values were DCA (8.4 ng/L), TCA (0.8 ng/L), TeCa (0.6 ng/L), PCP (0.8 ng/L), TCP (0.8 ng/L), TeCP (1.2 ng/L), and PCP (1.1 ng/L) respectively. In cork stoppers, the amounts of 2,4,6 TCA ranged between 5.4–130.6 ng/g. The 2,3,4,6 TeCA ranged between 1.12‐8.2 ng/g and the PCA ranged between nd (not detected)‐11.01 ng/g. In the wine samples, 2,4,6 TCA ranged between 1.42–70.2 ng/L. The 2,3,4,6 TeCA ranged between nd‐15.1 ng/L and the PCA ranged from nd‐5.16 ng/L. The results indicated that there was a significant correlation between the TCA in wines and the TCA in cork stoppers.     

Presence of cork-taint responsible compounds in wines and their cork stoppers

 Chloroanisoles [2,4-dichloroanisole, 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole and pentachloroanisole], chlorophenols [2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol (PCP)] and guaiacol were detected in red and white cork-tainted bottled wines. These compounds were also found in the cork stoppers from those bottles. A significant correlation was found between TCA in wines and TCA in cork stoppers, and between TCA in wine and intensity of cork taint. At low levels of TCA, the presence of guaiacol or PCP were also found to influence in cork taint. Received: 29 November 1999     

Influence of granule properties and concentration on cork-cement compatibility

Cork granules are produced as by-products and waste by the cork processing industries that make ‘bottle stoppers’ as a main product. These granules are of low density and could be used as lightweight aggregates for making concrete. This paper describes an investigation carried out to assess the compatibility of cork granules with cement for the manufacture of lightweight cementitious composites. Five different grades of cork granules varying in terms of size and density were investigated. The effects of extractives, particle size and density of the cork granules were studied. The results indicate that these parameters affect cement hydration in a complex way. At lower concentrations of cork (10%), only the extractives have an influence on hydration behaviour. At higher cork concentrations (20% and 30%), however, particle size and density also affect the compatibility. Nevertheless, cork granules are found to be compatible with cement.     

葡萄酒和软木塞中2,4,6-三氯苯甲醚检测方法的研究进展

本文介绍了葡萄酒和软木塞中2,4,6-三氯苯甲醚（2,4,6-trichloroanisole,TCA）的来源及影响,分析了2,4,6-三氯苯甲醚的检测难点,总结了目前检测2,4,6-三氯苯甲醚方法的总体趋势及现状。按照前处理方法的原理分类,介绍了前处理方法的定义、特点,并概述和讨论了前处理方法在萃取葡萄酒和软木塞中2,4,6-三氯苯甲醚中的应用;根据仪器检测方法的不同特点,总结和讨论了仪器检测方法在分析检测葡萄酒和软木塞中2,4,6-三氯苯甲醚的应用。前处理方法和仪器检测方法相结合,达到了浓缩和检测葡萄酒和软木塞中2,4,6-三氯苯甲醚的目的。     

Multitoxin evaluation in fermented beverages and cork stoppers by liquid chromatography–tandem mass spectrometry

A total of twenty‐eight mycotoxins were surveyed in wine (red, white and rose), cider (white and rose) and their cork stoppers from eight countries. Toxins of different fungi genera were detected as follows: Alternaria (ATs: alternariol – AOH; alternariol methyl – AME) and Penicillium/Aspergillus (ochratoxin A – OTA; penicillic acid – PAC). Toxins and levels varied with the sample types and country of origin. Wine presented contamination of OTA, AOH and AME. OTA was detected in forty‐one wine samples with levels ranging from 0.01 to 0.86 μg L^?1, below EU legislation. AOH and AME were detected in thirty‐three and eight of wines samples, respectively, at levels from 0.2 to 13.3 μg L^?1, while no contamination was detected in ciders up to the method LOQs. Regarding the cork stoppers toxins detected, they were AOH, AME and PAC. Corks of red wine from different countries had levels of OAH and AME ranging from 5.0 to 101.0 and 2.5 to 5 μg g^?1, respectively. It is necessary to pay more attention on the corks processing and cork type used in the bottles as, different from the ordinary ones, the ground bark and compressed type did not have toxins detected.     

Cork-borne bacteria and yeasts as potential producers of off-flavours in wine

Bacteria and yeasts were found to be present within cork lenticels, covered by mucous or fibrous substances. They survived heating, peroxide treatment and contact with the alcohol and sulfur dioxide of wine. 187 bacteria and 36 yeast strains were isolated from cork stoppers of wine bottles and, during various stages of production, from corkwood and new cork stoppers. After culturing, a number of isolates showed the ability to modify the aroma of model systems consisting of dilute or full strength wine and pulverised cork. The aromas produced by isolates of varying cork origin are tabled. A small number of isolates methylated 2,4,6-trichlorophenol, yielding 2,4,6-trichloroanisole, responsible for the typical cork taint. During the boiling of cork slabs, the internal temperature on the inside of a box made from cork slices did not exceed 87°C.     

Matrix effect during the application of a rapid method using HS-SPME followed by GC–ECD for the analysis of 2,4,6-TCA in wine and cork soaks

An off-flavor in wine known as ‘cork taint’ is of concern in the wine and cork industry. Cork taint imparts a musty flavor to the wine and is primarily due to the presence of 2,4,6-trichloroanisole [2,4,6-TCA] in cork stoppers. During this study, an instrumental method for 2,4,6-TCA analysis was developed and evaluated using headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with an electron capture detector (GC–ECD). 2,3,6-Trichlorotoluene [2,3,6-TCT] was assayed as the internal standard. The method was developed in synthetic wine and was applied in commercial wine samples, as well as in cork soaks obtained by the extraction of TCA from cork stoppers and cork barks using synthetic wine. The method performance was evaluated through the estimation of its linearity (R² > 0.99), repeatability (RSD value = 5.72%) and sensitivity (recovery > 86%, LOD = 0.177–0.368 ng/L) in different types of samples. Due to the complexity of the samples used, the study has been especially focused on the matrix effects that were identified causing significant bias to the quantitative analysis of 2,4,6-TCA in cork soaks, where there is a lack of previous studies.     

The analysis of natural cork stoppers in transversal sections as an effective tool to determine the origin of the taint by 2,4,6-trichloroanisole

The distribution of several chlorophenols (CPs) and chloroanisoles (CAs), including 2,4,6-trichloroanisole (TCA), the main compound responsible for fungal taint of wines, was analyzed in four independent batches of natural cork stoppers that were dissected into three transversal slices. The contaminants were homogeneously distributed in the slices analyzed. All the stoppers were contaminated with at least one single CP or CA, although most of the corks contained several CPs and CAs. Pentachlorophenol was the more abundant contaminant, detected in 89.2% of the corks analyzed. The analysis of releasable CPs and CAs showed that most of the contaminants present in the stoppers cannot be released into wine. The same compounds were analyzed in a different batch of natural cork stoppers that had been used to close wine bottles in a winery whose facilities were contaminated with CPs and CAs. In this case, the highest amounts of contaminants were accumulated on the heads of the stoppers in contact with the winery environment. Bottled corks were able to efficiently absorb deuterium-labeled TCA (TCA-d ₅) and/or deuterium-labeled pentachloroanisole (PCA-d ₅) from an artificially tainted wine during 40 months. In this case, most of the TCA-d ₅ and PCA-d ₅ was located in the basal slices of the closures in direct contact with wine. These data, and also data from other authors, indicate that the distribution in transversal slices of the CPs and CAs contaminating cork stoppers is in direct relationship with the origin of the taint, and therefore that the analysis of cork stoppers by transversal sections could be an effective tool to clarify the origin of the taint.     

Effect of wine style on the perception of 2,4,6-trichloroanisole,a compound related to cork taint in wine

2,4,6-Trichloroanisole (TCA) is a fungal metabolite that can contaminate cork stoppers and wines producing a very unpleasant mouldy odour (cork taint). Sensory control is very widely used for the detection of possible TCA presence in corks and wine, but the correct identification of TCA, especially at low concentrations, can be difficult. The aim of this study was to show how wine styles can affect the ability of the same panel to perceive TCA. For this purpose, a panel was selected, according to the panelists’ sensitivity to the TCA stimulus. The triangle test, a sensory difference test, was carried out by the panel with both white and red wines, using samples both free from TCA and spiked with known quantities of this contaminant. The results showed that the panelists identified the difference caused by the added TCA at different significance levels, depending on the wine style, so TCA detection was influenced by wine style for the selected panel.     

Organotin pollution in deep-sea fish from the northwestern Mediterranean

Aquatic pollution resulting from extensive usage of organotin compounds has been of great concern due to their deleterious effects in nontarget organisms. However, organotin contamination in deep-sea ecosystems has been rarely studied. The presentwork attempted to determine butyltin and phenyltin compounds in deep-sea fish collected between 1000 and 1800 m depth in the NW Mediterranean. The concentration of tributyltin (TBT) and its degradation products, mono- (MBT) and dibutyltin (DBT), aswell astriphenyltin (TPT),and mono- anddiphenyltin (MPT, DPT) was determined in different tissues (liver, gills, digestive tube, and muscle) of several fish species. Total butyltin residues were up to 175 ng/g wet wt, and they were comparable to levels found in coastal fish collected along the Catalan coast. In contrast, deep-sea fish contained much higher levels of phenyltins (up to 1700 ng/g wet wt), and particularly TPT (up to 1430 ng/g wet wt), than previously reported concentrations in shallow-water organisms. The obtained results confirm the long-range transport of organotin compounds to the deep-sea environment, and the subsequent exposure of fish inhabiting nonpoint source areas. The use of TPT in agriculture or as an antifouling agent, its transport to the deep-sea environment associated to particulate matter, and its nonbiodegradable nature in the food chain may account for the high residue levels detected in deep-sea organisms.     

Development and evaluation of alternative processes for sterilization and deodorization of cork barks and natural cork stoppers

Cork taint, one of the most known off-flavours in wine, is usually attributed to the presence of the aromatic compound 2,4,6-trichloroanisole (2,4,6-TCA) in cork stoppers made from the bark of the cork oak, Quercus suber. There are many major chemical/biochemical pathways through which 2,4,6-TCA can be formed during cork production. The estimated incidence of cork-tainted wine bottles ranges from 2–to 7%, costing global wine industry approximately US$ 10 billion annually. During this study, a laboratory-scale system was designed and constructed, to efficiently treat cork bark and stopper samples using ozone and/or other sterilizing gases, such as steam, via sequential application of pulsed vacuum–pressure cycles. The developed physicochemical processes were studied and evaluated in order to achieve both sterilization conditions and 2,4,6-TCA removal without affecting the mechanical and bottling properties of cork. According to the results, the application of ozone alone seems to be a promising treatment method for cork barks. However, the pulsed treatment ensures both sufficient removal (99%) of both bacteria and moulds from cork stoppers when combined with ozone or steam and satisfactory deodorization of cork stoppers achieving high percentages (90%) of 2,4,6-TCA removal when combined with steam. The operating cost of each alternative process (plain or pulsed, with or without ozone and/or steam) was estimated and compared, in laboratory scale, for the selection of the most efficient process, taking into account technicoeconomical aspects.     

Sealing and Storage Position Effects on Wine Evolution

Sealing system and bottle storage position effects on the evolution of white and red wines were analyzed. The sealing systems were natural‐cork stopper, colmated‐cork stopper, agglomerated‐cork stopper, polyurethane‐powdered‐cork (PPC) stopper, plastic stopper, and metal screw‐top. Chemical analysis and sensory analysis showed that wine is better preserved when the bottles are kept horizontally. The sealing systems that allowed the most suitable evolution were the natural‐cork stopper, the colmated‐cork stopper, and the PPC stopper. The agglomerated cork produced faster wine oxidation when the bottles were kept vertically. The plastic cork and the screw‐top allowed oxidation in the wine more quickly than the other systems.     

Influence of vision systems,black and white,colored and visual digitalization,in natural cork stopper quality estimation

Quality classification of wine natural cork stoppers is related to presence of discontinuities in the cork tissue. Automated image analysis of stoppers based on black and white cameras is used industrially for commercial classification but recently color has been introduced in image processing. This paper compares the performance of three image vision systems regarding classification accuracy of cork stoppers of good, medium and inferior quality: black and white, three‐band RGB color and manual detection by digitalization in color image. A canonical discriminant analysis approach was used to compare the discriminating power between cork stopper quality in each vision system. Good discriminant results were obtained with the area of pores expressed either in total or as ratio, mean or maximum value. The use of color slightly enlarges the range of cork inspection systems and automated systems have a similar accuracy of classification to visual inspection. Copyright © 2007 Society of Chemical Industry     

Dynamic mechanical analysis and creep-recovery behavior of agglomerated cork

The mechanical behavior of agglomerated cork, made of cork granules bound with polyurethane moisture-cured adhesive is investigated and compared to natural cork in the small strain regime (strain?<5%). Dynamic mechanical analysis (DMA) of the agglomerated material revealed two distinct thermal transitions, one at ?45?°C, related to the glass transition of polyurethane, and one at 3?°C, associated with melting of suberin, a natural polyester that is the main component of cork’s cell walls. Natural cork showed the latter transition to occur at a higher temperature range, between 10 and 25?°C, probably due to a different crystalline arrangement being formed upon cooling the cork granules under pressure in the mold. The storage modulus of agglomerated cork was found to be similar to that of natural cork. Creep and recovery experiments were well described by Burgers model and Weibull distribution function, respectively. Agglomerated cork showed higher instantaneous creep strain and viscous flow than natural cork, probably due to relative displacement and slippage of the granules being allowed by the binder. In all cork materials, not all the instantaneous creep strain was instantaneously recovered. A fraction underwent delayed recovery and another turned into permanent strain. This behavior was associated with the deformation of corrugations in the cork cell walls. Cyclic creep-recovery tests showed for all cork materials recoveries above 90%, except for the first cycle.     

Further evidence for the existence of PCDD/Fs in the environment prior to 1900

PCDD/Fs and PCBs have been analyzed in a series of archived soil samples collected from various depths during the 1800s and early 1900s. PCBs were not found in soil samples collected before 1900, whereas PCDD/Fs were present in concentrations between 43 and 110 pg/g in surface soils, and between 9 and 150 pg/g in soils collected from below the surface. The PCDD/F homologue patterns of all surface soils were consistent with each other. The homologue pattern of deeper soils altered with depth to one that was dominated by highly chlorinated PCDDs. The highest sigma(4-8)PCDD/F concentration (150 pg/g) was found in the deepest soil analyzed (230-250 cm below the surface). The cork from one of the storage bottles contained considerable quantities of both PCBs and PCDD/Fs. However, contamination of the soils, either by diffusion through the cork or by cork particles, was discounted on the basis that no PCBs were evident in the soil, and that the PCDD/F homologue pattern in the cork was very different to that found in the soil. Similar arguments were used to discount contamination of the soil by dust. A sample of ashed vegetation from the archive, that had no cork stopper, contained high concentrations of PCBs (78 ng/g), concentrations of mono- to tri-CDFs that were higher than in any of the soils (190 pg/g), but very low concentrations of sigma(4-8)PCDD/F (12 pg/g). This pattern of analytes was considered to be representative of contamination from store room air and was completely different from the pattern observed in the soils. Taken together these observations indicate that contamination during storage, or subsequent handling, is unlikely to have occurred in archived soil samples that were stored with cork and wax seal intact. The results imply surface soil sigma(4-8)PCDD/F concentrations of around 60 pg/g at Rothamsted (southeast England) in the late 1800s, compared with approximately 300 pg/g reported for rural UK soils in the 1990s.     

Evaluation of the performances of synthetic and cork stoppers up to 24 months post-bottling

In recent years, as a consequence of higher market prices for cork and of the qualitative problems created by natural stoppers, the demand for alternative seals has increased remarkably . Since 1990, numerous manufacturers of plastic materials have begun production of synthetic stoppers for the closure of wine bottles. The application of the first experimental products was highly unsatisfactory and showed the need to carry out more research into the characterisation of the materials employed and their interaction with the "matrix wine". The object of this study was to estimate the mechanical characteristics of a particular kind of synthetic stopper and to compare the physico-chemical profiles of different Italian wines bottled with corks, or with synthetic stoppers made of expanded polyethylene, during the wine conservation phase. Analytical and statistical data produced give assurance that for these wine types, the employment of the synthetic stopper helps to increase the shelf-life of wines ready to consume within 1–2 years after bottling.     

Migration of 2,4,6-trichloroanisole from cork stoppers to wine

The migration of 2,4,6-trichloroanisole (TCA) from cork stoppers to wine is studied under different experimental conditions. Corks that were either naturally contaminated or spiked with a TCA solution were immersed in an ethanol–water mixture (12% v/v) for 6 days or were used as a closure for bottled wines over periods of 1, 4 and 8 months. The TCA content was determined after the stated periods using headspace solid-phase microextraction and gas chromatography electron capture detection. Three different spiking procedures were tested: the injection of a TCA solution into the cork, the immersion of the cork in a TCA in hexane solution, and cutting off a thin slab to inject different quantities of a TCA solution into it before rejoining the two parts. Only the first of these procedures was subsequently used as the immersion technique failed to retain sufficient quantities of TCA and the slab technique retained too much. Corks spiked with 120 ng TCA gave 8% migration after 6 days for corks used in the immersion experiments and less than 1% migration for corked bottles kept for 1 month. When the contact time was 4 and 8 months, migration was 4 and 8% respectively for corks spiked with 1 g TCA. It was concluded that the contact surface, temperature and time all favour TCA migration. Under the same conditions, wine bottled with naturally contaminated cork stoppers showed TCA concentrations which varied depending on the characteristics of every individual cork stopper.     

Sorption and diffusion properties of volatile phenols into cork

The sorption and diffusion properties of seven common volatile phenols in hydro-alcoholic medium placed in contact with natural cork were investigated to determine the influence of cork closures on the concentration of these compounds in wine. Weighted cork samples were immersed in model wine solutions containing selected concentrations of each compound and were sampled over time. Sorption coefficients ranged between 125 and 306 mg of aroma compound per kg of cork, while diffusion coefficients varied from 0.8 to 4.1 × 10⁻¹¹ m²/s. Sorption isotherms of guaiacol and 4-propylguaiacol, respectively, the lowest and highest sorbed compounds of an homologous series of guaiacol, accurately fit Henry’s model. Hydrophobicity of aroma compounds seems to be a determining factor in both diffusion and sorption. This could indicate a preferential pathway for diffusion through suberin, the more hydrophobic constituent of cork.