A Cork Cell Wall Approach To Swelling And Boiling

The bark of cork oak (Quercus suber L.) is mostly used for cork stopper production, whereas bark is undergoing a series of industrial procedures, boiling usually leading to changes in the characteristics of the tissue. Trees are traditionally grown under natural conditions; however, irrigation is now being used in plantations. These permanent water availability affects cork-oak development, while its effects on industrial procedures is unknown. This study provides a first insight into the behaviour of the cell walls of cork during the process of swelling and boiling when trees have been grown under irrigation, subject to a specific water regime. Cork tissue was analysed using environmental and scanning electron microscopy under three regimes: raw conditions; following immersion in water; and after boiling. Additionally, the radial expansion of samples was determined. The results showed greater cell-wall expansion in cork from the irrigated site than cork from the traditional rainfed plot, when hydrated for 24h. After boiling, the cell walls of the rainfed site were thinner than in the raw stage, in contrast to the irrigated cork. This study suggests that irrigation during cork-oak growth produces a higher capacity for adsorption, increasing cell-wall thickness from the raw stage to the boiling stage.

Design thinking in responding to disruptive innovation: A case study

How can the design thinking approach assist firms in developing response strategies to momentum-gaining disruptive innovations, along the lines of effectively exploiting established technologies and corresponding products/services? Such exploitative response strategies, implying successfully strengthening and leveraging the disrupted firm's existing technology without embracing the disruptive elements, have been, to a large extent, overlooked in the disruptive innovations literature. Using an inductive analysis of a critical case (a major cork stopper producer), the current study aims at developing a systematic understanding of exploitative strategic options and the role of design thinking in enabling them. The findings shed light on the effectiveness of the design thinking mindset to respond to disruptive innovations. In addition, we present evidence that a design thinking method can be successfully applied to process innovation. Finally, we demonstrate that to achieve a radical innovation based on design thinking principles, the establishment of design discourse is required.

Design and Comparison of Image Hashing Methods: A Case Study on Cork Stopper Unique Identification

Cork stoppers were shown to have unique characteristics that allow their use for authentication purposes in an anti-counterfeiting effort. This authentication process relies on the comparison between a user’s cork image and all registered cork images in the database of genuine items. With the growth of the database, this one-to-many comparison method becomes lengthier and therefore usefulness decreases. To tackle this problem, the present work designs and compares hashing-assisted image matching methods that can be used in cork stopper authentication. The analyzed approaches are the discrete cosine transform, wavelet transform, Radon transform, and other methods such as difference hash and average hash. The most successful approach uses a 1024-bit hash length and difference hash method providing a 98% accuracy rate. By transforming the image matching into a hash matching problem, the approach presented becomes almost 40 times faster when compared to the literature.

Evaluation of the Storage Conditions and Type of Cork Stopper on the Quality of Bottled White Wines

The effects of different storage conditions, light exposure, temperature and different commercially available cork stoppers on the phenolic, volatile and sensorial profile of Verdejo wines were studied. Two natural corks of different visual quality and a microgranulated cork stopper were investigated over one year at two different storage conditions. One simulating light exposure and temperature in retail outlets and the other simulating optimal cellar conditions (darkness and 12 °C). The wines stored under commercial conditions showed greater losses of total and free SO2 and higher levels of brown-yellowish tones, related to the oxidation of flavan-3-ols. Although these wines underwent a decrease in the total content of stilbenes, a significant increase in trans-piceid was observed. In addition, these wines suffered important changes in their volatile and sensory profile. Volatile compounds with fruity and floral aromas decreased significantly, while volatile compounds related to aged-type characters, as linalool oxides, vitispirane, TDN or furan derivatives increased. Wines stored in darkness at 12 °C underwent minor changes and their sensory profiles were similar to wine before bottling. The high-quality natural corks and microgranulated corks better preserved the quality of the white wines from a sensory point of view. These results showed that temperature and light exposure conditions (diffuse white LEDs and 24 ± 2 °C) in retail outlets considerably decrease the quality of bottled white wines and, consequently, their shelf life, due to the premature development of aged-type characters.

The Effect of the Storage on the Content of the Malvidin-3-Glucoside in Red Wine

Anthocyanins are plant dyes responsible for the colour of red wine. Of these, malvidin-3-glucoside is the most significant member and its content was monitored in wines that were first left to age in oak barrels for 12 months, subsequently bottled and sealed with plastic/cork stoppers. The malvidin-3-glucoside content was also studied in the same wines that were bottled right away without aging in barrels. Analyses were conducted within the time spans of 3 to 30 months. The highest malvidin-3-glucoside concentrations were found in month 3 of the aging process, and they significantly decreased in month 6 and month 15 of storing. Between month 15 and month 30 of storing, the content of malvidin-3-glucoside basically remained unchanged. The results of the measurements show that to preserve higher malvidin-3-glucoside levels for longer periods of time, it is better to store wine in barrels rather than in bottles and when a bottle is used instead of a barrel, a plastic stopper is better than a cork stopper.

Optimum cork stopper diameter for a proper wine sealing performance when modifying bottleneck diameter: a first approach

Aim of study: This study present a theoretical model that allow establishing the proper relationship between forces and diameters that take part in sealing for ensuring an adequate closure during storage time, and obtained the optimum stopper diameter for a proper sealing performance when modifying bottleneck diameter.Area of study: The proposed model is of interested to the whole cork value chain from forest owners to natural cork stoppers manufacturers.Material and methods: The optimum cork stopper diameter depends mainly on stopper quality and the compression rate applied in the bottling operation. In this study, we establish the stopper diameter when reducing bottleneck diameter, applying a compression rate of 33% when corking, and for natural cork stoppers which quality allows to recover its initial diameter to 96% after 24 h since compression.Main results: For a bottleneck diameter of 18 mm, the value of the stopper diameter should be at least of 22.3 mm, and for a bottleneck diameter of 17 mm, the value of the stopper diameter should be at least of 20.3 mm.Research highlights: These results try to solve one of the main worries of natural cork stopper manufacturers, which is the scarcity of raw cork suitable for manufacturing them. However this study is also of interested to forest owners because the increment of cork suitable for natural cork stoppers manufacturing means an increment in cork value.Key words: bottling; corking; compression force; compression rate; diameter recovery; relaxation force; relaxation ratio.Abbreviations used: Ds (Cork Stopper Diameter); Dg (Caliper Diameter the Corking Machine); Db (Bottleneck Diameter); Dr (Recovered Diameter); Fc (Compression Force); Fr (Relaxation Force); CR (Compression Rate); RR (Relaxation Ratio); RD (Diameter Recovery).

Biosorption of Cationic Dyes onto Cork Stopper Particles by Inverse Fluidized Bed

In this study cork stopper particles was used as a low cost biosorbent to remove the cationic dyes (Methylene blue (MB), Malachite green (MG), and Methyl violet (MV)) from simulated wastewater. Continuous experiments were studied in a laboratory scale in inverse fluidized-bed packed with cork stopper particles for removal these dyes. A set of continuous mode experiments was carried out in inverse fluidized bed column to study the effect of flow rate (10, 15, 20 l/h), bed depth (5, 10, 15 cm), and influent concentration (10, 20, 30 mg/l) on the performance of biosorption process onto cork stopper particles. The minimum inverse fluidized velocity was calculated and it was found to be 8 ×10-5 m/s. The results indicate that cork adsorbs dyes efficiently and can be used as a low-cost alternative for the removal of cationic dyes in wastewater treatment.

Biosorption of Cationic Dyes onto Cork Stopper Particles

In this study, cork stopper particles were used as a low cost biosorbent to remove the cationic dyes (Methylene blue (MB), Malachite green (MG), and Methyl violet (MV)) from simulated wastewater. Batch sorption experiments of components were conducted as a function of pH, sorbent dosages, contact time, agitation speed, and particle size to optimize the best conditions for maximum removal efficiencies of dyes. The experimental data fitted slightly best to the Langmuir isotherm model than to Freundlich and Temkin isotherm model. The experimental data proved that the adsorption kinetic of MB, MG, and MV could be described by a pseudo-second order model. The results indicate that cork adsorbs dyes efficiently and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.