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The production of high-quality aged marc spirits includes a minimum period of six months of ageing in oak barrels. Lastly, producers are interested in alternative botanical origin wood. The present study is aimed at investigating the influence of Greek oak (Quercus trojana) and Greek chestnut (Castanea sativa) compared with French (Quercus petraia) and American oak (Quercus alba) on the chemical composition and sensorial characteristics of aged tsipouro, produced from marc from the Black Muscat variety. Gas chromatography–olfactometry–mass spectrometry (GC–O–MS) was used to identify volatile compounds of the aged tsipouro. Also, colour and polyphenol measurements were made, and an organoleptic evaluation was performed by 16 trained tasters. The findings revealed rather similar results between the tsipouro made from different wood species, especially between Greek and French oaks, and relative differentiation for that of chestnut. All the aged distillates exhibited a pleasant and rich aromatic potential, dominated by floral and fruity terpene varietal aromas as well as wood-related volatiles. Chestnut, with a high phenolic potential, gives pleasant organoleptic effects over time and can be an alternative wood for ageing spirits. This research highlights the importance of wood selection in the tsipouro ageing process and enables the use of Greek wood species in the ageing of spirits. [ABSTRACT FROM AUTHOR]

ABSTRACT The aroma of fine matured spirits is typically complex, resulting from numerous reactions occurring during the production process and some developing during maturation in oak casks. The refreshing sensation brought by mint notes was often expected, even after years of maturation. The main challenge lies in achieving an aromatic balance characterised by the seamless integration of woody aromas while maintaining the initial distillate's freshness. The present study examines the sensory effects associated with the interactions between wood, mint and cold sensations in spirits. Nine spirit model solutions were prepared, representing different combinations of terpene ketones (imparting mint aroma) and wood compounds, each at three concentration levels. The quantitative composition of mint compounds simulated varying degrees of mintiness in the distillate (low, medium and high), while the concentrations of wood compounds mimicked three maturation periods (short, intermediate and long term) in wooden casks. Samples were sensorily analysed by discriminative (triangle test) and rate‐all‐that‐apply (RATA) methodologies. An increase in woody intensity was notably perceived in samples with a low‐mint profile and containing wood compounds associated with medium and long‐term maturation. However, no significant sensory differences were observed in mint and cold perception between model solutions regardless of the simulated maturation conditions, indicating a limited influence of the studied wood compounds on the sensation of freshness in spirits due to competitive perceptual interactions with terpene ketones. [ABSTRACT FROM AUTHOR]

The effects of air heat treatment were evaluated on six Korean oak woods: Quercus serrata (Qs), Quercus mongolica (Qm), Quercus acutissima (Qac), Quercus aliena (Qal), Quercus dentata (Qd), and Quercus variabilis (Qv). Color change (ΔE*), weight loss, and density loss were examined using flat-sawn heartwood boards before and after treatment at 160 °C, 180 °C, 200 °C, and 220 °C for 2 h. Overall, the ΔE*, weight loss, and density loss increased with temperature. The properties between temperature and species showed distinct differences. A change to a darker color was observed in all species after treatment at 200 °C. Qm and Qd exhibited the highest and lowest L*, a*, and b* values after treatment at 220 °C, respectively. The highest ΔE* values were obtained in Qd at 160 °C, Qs at 180 °C and 200 °C, and Qv at 220 °C. Qd and Qv exhibited the highest and lowest weight losses at 160 °C, respectively. Qac and Qal showed the highest and lowest weight losses at 220 °C, respectively. Qm showed the highest density loss at all temperatures, whereas Qs had the lowest at 160 °C, and Qac had the lowest values at 180 °C, 200 °C, and 220 °C.

The effects of air heat treatment were evaluated on six Korean oak woods: Quercus serrata (Qs), Quercus mongolica (Qm), Quercus acutissima (Qac), Quercus aliena (Qal), Quercus dentata (Qd), and Quercus variabilis (Qv). Color change (ΔE*), weight loss, and density loss were examined using flat-sawn heartwood boards before and after treatment at 160 ℃, 180 ℃, 200 ℃, and 220 ℃ for 2 h. Overall, the ΔE*, weight loss, and density loss increased with temperature. The properties between temperature and species showed distinct differences. A change to a darker color was observed in all species after treatment at 200 ℃. Qm and Qd exhibited the highest and lowest L*, a*, and b* values after treatment at 220 ℃, respectively. The highest ΔE* values were obtained in Qd at 160 ℃, Qs at 180 ℃ and 200 ℃, and Qv at 220 ℃. Qd and Qv exhibited the highest and lowest weight losses at 160 ℃, respectively. Qac and Qal showed the highest and lowest weight losses at 220 ℃, respectively. Qm showed the highest density loss at all temperatures, whereas Qs had the lowest at 160 ℃, and Qac had the lowest values at 180 ℃, 200 ℃, and 220 ℃. [ABSTRACT FROM AUTHOR]

There is a trend towards the commercialisation of strawberry tree fruit spirit (AUS) with wood ageing, motivated by its favourable sensory characteristics. Additionally, further studies are necessary to elucidate the optimal conditions regarding ageing time and toasting level. This study evaluated the changes in colour and low molecular weight compounds (LMWC) of AUS aged for three and six months using oak wood (Quercus robur L.) with light, medium and medium plus toasting levels. For this purpose, phenolic acids (gallic, ellagic, ferulic and syringic acids), phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and furanic aldehydes (furfural, 5-hydroxymethylfurfural and 5-methylfurfural) were quantified using the HPLC method. Chromatic characteristics, colour sensory analysis and total polyphenol index were also analysed. Fourier transform near-infrared spectroscopy (FT-NIR) was used to discriminate between samples. The results emphasized the favourable effect of oak wood contact on enhancing the colour and enriching AUS with low molecular weight compounds (LMWC). AUS aged in medium toasted wood exhibits high levels of total phenolic index, 5-hydroxymethylfurfural, furfural, coniferaldehyde, sinapaldehyde, sum LMWC and chromatic characteristics b* and C. Concentrations of syringaldehyde, ellagic acid, vanillin and syringic acid and a lighter colour (a* chromaticity coordinates) are higher in AUS aged with slightly more toasted wood. Nearly all analysed parameters showed an increase with ageing time. The FT-NIR technique allowed for the differentiation of aged AUS, focusing more on ageing time than on toasting level. [ABSTRACT FROM AUTHOR]

Corrosion and friction coefficient tests were performed on solid oak wood machined with hard-metal woodworking tools coated with PVD coatings (AlCrN, AlTiN, TiAlN, TiCN and CrN). The tannic acid attacks the carbide more intensively than the PVD coatings. During cutting, corrosion spreads on the cutting edge of the cutter due to mechanical action, which dissolves the cobalt binder of the hard-metal and causes the carbide grains to flake off. After 80 min of contact with the wood, the cobalt content decreases from 3.53 to 1.74%. Depending on the PVD coating material, cracks of 4 to 40 µm in width appear after 120 min (9000 m cutting path). After 120 min of machining, wear, corrosion effects and the influence of corrosion on the coefficients of friction were evaluated for tools with and without PVD coatings. TiCN is the most sensitive to corrosion, while AlCrN and CrN coatings are the least sensitive, with the AlTiN coating being the most affected under real cutting conditions (with mechanical + thermal + corrosion effects) and the tools with CrN and AlCrN coatings being the least affected. Corrosion affects the hard-metal and PVD coatings and reduces the coefficient of friction. The angle between the directions of sliding and sharpening of the cutting edge sharpening significantly influences this parameter. The coefficient of friction of hard-metal WC-Co and PVD coatings is higher in the parallel machining direction than in the perpendicular machining direction and ranges from 16.03% (WC-Co) to 44.8% (AlTiN). The coefficient of friction of hard-metal WC-Co decreases by 5.13% before and after exposure to tannic acid, while the corrosion of PVD coatings reduces it by 4.13% (CrN) to 26.7% (TiAlN). [ABSTRACT FROM AUTHOR]

The production of high-quality aged marc spirits includes a minimum period of six months of ageing in oak barrels. Lastly, producers are interested in alternative botanical origin wood. The present study is aimed at investigating the influence of Greek oak (Quercus trojana) and Greek chestnut (Castanea sativa) compared with French (Quercus petraia) and American oak (Quercus alba) on the chemical composition and sensorial characteristics of aged tsipouro, produced from marc from the Black Muscat variety. Gas chromatography–olfactometry–mass spectrometry (GC–O–MS) was used to identify volatile compounds of the aged tsipouro. Also, colour and polyphenol measurements were made, and an organoleptic evaluation was performed by 16 trained tasters. The findings revealed rather similar results between the tsipouro made from different wood species, especially between Greek and French oaks, and relative differentiation for that of chestnut. All the aged distillates exhibited a pleasant and rich aromatic potential, dominated by floral and fruity terpene varietal aromas as well as wood-related volatiles. Chestnut, with a high phenolic potential, gives pleasant organoleptic effects over time and can be an alternative wood for ageing spirits. This research highlights the importance of wood selection in the tsipouro ageing process and enables the use of Greek wood species in the ageing of spirits.

The influence of laser cutting parameters on cutting quality of tussah by CO laser was studied, and the optimal combination of technical parameters was obtained. Orthogonal test method was used to study the influence of light intensity, feed speed and lens on seam width and seam depth, and to analyze the variation rule of main effect and interaction test data. The results showed that the main factor affecting laser cutting was lens height, and the interaction between feed speed and light intensity was significant. In actual production, the optimal combination of technical parameters can be determined according to different cutting effects required, such as laser cutting of tussah wood with water content of 6.5%, in order to obtain seam depth of about 3 000 μ m, seam width of about 200 μ m, 5 mm lens height, 40 mm/s feed speed and 40% laser intensity. [ABSTRACT FROM AUTHOR]

A technique for manufacturing wood heat-insulating material for construction (known as wood delignification) without seriously affecting the cellulosic structure was inspired by the practices of the pulp and paper industry and adapted to the mentioned purpose. Among the numerous known methods of chemical treatment of wood for removing the lignin in the paper industry, the use of the suspension generated by mixing of NaOH, Ca(OH)2, and distilled water at 260 ℃ in an electric oven was adopted. For the first time, oak wood (recycled in the form of sawdust) was chosen as the basic raw material in the wood delignification process due to its large availability in Romania's climatic conditions. Using 58 % oak wood, 23.3 % NaOH, 16.7 % Ca(OH)2, and water addition, the best product had very low values of density (0,024 g·cm-3) and heat conductivity (0.031 W·m-1·K-1) as well as an acceptable value of compression resistance (0.9 MPa) for construction applications. [ABSTRACT FROM AUTHOR]

• An interdisciplinary study has clarified that the painting was created several decades after Nicolaus Copernicus's death. • The portrait was most probably painted in the 1580s and it is one the three oldest surviving images of the astronomer. • The wood was probably transported from a Lithuanian or Belarusian forest to the artist's studio in Flanders or northern Germany. • The portrait underwent a manual dendrochronological analysis in 1987 which demonstrated better statistical parameters than the updated study in 2023. Revealing more detail on the biography of art objects, such as their attribution, dating or the artist's methods and techniques, requires a multidisciplinary approach that includes dendrochronology as a means of providing the chronological order. The 550th anniversary of the birth of Nicolaus Copernicus (1473–1543) offered an opportunity to conduct an in-depth study of the Toruń portrait of the Great Astronomer, also from a technological and art-historical point of view, and to compare the present findings with the results of the first attempt at dendrochronological dating made in 1987. The analysis of the painting from 2023 showed the following results of dendrochronological dating with the following end dates and time spans of tree ring series: board no. 2 - end date AD 1558, time span AD 1287–1558; and board no. 3 - end date AD 1500, time span AD 1439–1500 and unambiguously demonstrated that this most widely known image of Copernicus was created after his death. While the author of the painting is unknown, the stylistic features may suggest influences of Netherlandish or Flemish painters. The painting panel was made from Baltic oak of Lithuanian or Belarusian origin, and the well-corresponding tree-ring series of numerous Flemish paintings suggest Flanders as the origin of the Portrait of Nicolaus Copernicus. A comparison of the results of the two dendrochronological studies – conducted in 1987 and 2023 using vastly different technological capabilities – provides clear evidence that the tree-ring series developed by the pioneers of art-historical dendrochronology, together with their vast databases, can be used with great confidence. [ABSTRACT FROM AUTHOR]

There is a trend towards the commercialisation of strawberry tree fruit spirit (AUS) with wood ageing, motivated by its favourable sensory characteristics. Additionally, further studies are necessary to elucidate the optimal conditions regarding ageing time and toasting level. This study evaluated the changes in colour and low molecular weight compounds (LMWC) of AUS aged for three and six months using oak wood (Quercus robur L.) with light, medium and medium plus toasting levels. For this purpose, phenolic acids (gallic, ellagic, ferulic and syringic acids), phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and furanic aldehydes (furfural, 5-hydroxymethylfurfural and 5-methylfurfural) were quantified using the HPLC method. Chromatic characteristics, colour sensory analysis and total polyphenol index were also analysed. Fourier transform near-infrared spectroscopy (FT-NIR) was used to discriminate between samples. The results emphasized the favourable effect of oak wood contact on enhancing the colour and enriching AUS with low molecular weight compounds (LMWC). AUS aged in medium toasted wood exhibits high levels of total phenolic index, 5-hydroxymethylfurfural, furfural, coniferaldehyde, sinapaldehyde, sum LMWC and chromatic characteristics b* and C. Concentrations of syringaldehyde, ellagic acid, vanillin and syringic acid and a lighter colour (a* chromaticity coordinates) are higher in AUS aged with slightly more toasted wood. Nearly all analysed parameters showed an increase with ageing time. The FT-NIR technique allowed for the differentiation of aged AUS, focusing more on ageing time than on toasting level.

Microencapsulated phase change materials (MPCMs) incorporated into oak wood via vacuum impregnation have shown promise as thermal energy storage (TES) materials. Physical and chemical properties of MPCMs and resulting Phase Change Energy Storage Wood (PCESW) were analyzed. Scanning electron microscopy and particle size analyses revealed similar particle sizes, while X-ray diffraction (XRD) and Fourier transform infrared spectra confirmed crystal phase and chemical structure. Thermal gravimetric analysis (TGA) and differential scanning calorimetry determined thermal properties, including phase change temperature, enthalpy, thermal stability, and conductivity. The MPCMs exhibited a phase change enthalpy of 146.0 J/g and temperature of 35.0 °C, with excellent thermal stability. The FTIR, XRD, and TGA analyses showed unchanged chemical structure, crystallinity ratios, and decomposition in two stages, respectively. The PCESW exhibited a latent heat storage of 3.02 J/g at 25.4 °C. Decay tests demonstrated noticeably reduced weight loss (1.22% and 1.55%) for MPCMW samples treated with Trametes versicolor and Coniophora puteana, compared to unleached control samples (19.7% and 20.8%). These findings indicate the high efficiency and potential of PCESW as a thermal energy storage material.

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This study determined the impact of undertaking an initial treatment of oak wood by sealing its surface pores with epoxy resin, focusing on the durability of transparent coating systems when exposed outdoors. Throughout the exposure period, various parameters including color, gloss, surface wettability, and both macroscopic and microscopic surface evaluation were continuously monitored. The study involved two sets of samples: one set underwent the pretreatment, while the other did not. Subsequently, four coating systems were applied to the samples, comprising two solvent-based and two water-based coatings. The experiment was conducted over a period of two years, utilizing natural weathering methods within the premises of the Czech University of Life Sciences in Prague. The pretreatment with epoxy resin exhibited enhanced durability for all paint systems. The analysis showed a significant difference in gloss and color after 12 months of weathering exposure without any significant effect on surface wettability and sealing. However, after 24 months of the weathering exposure, no significant differences between the sealed and unsealed surface were observed. The most significant change in properties was noted for the water-based coatings used in coating systems number 3 and 4, and these coatings were rated as the best. [ABSTRACT FROM AUTHOR]

The world’s expanding population presents a challenge through its rising demand for wood products. This requirement contributes to increased production and, ultimately, the high-quality and efficient utilization of basic materials. Detecting defects in wood elements, which are inevitable when working with a natural material such as wood, is one of the difficulties associated with the issue above. Even in modern times, people still identify wood defects by visually scrutinizing the sawn surface and marking the defects. Industrial scanners equipped with software based on convolutional neural networks (CNNs) allow for the rapid detection of defects and have the potential to accelerate production and eradicate human subjectivity. This paper evaluates the suitability of defect recognition software in industrial scanners against software specifically designed for this task within a research project conducted using Adaptive Vision Studio, focusing on feature detection techniques. The research revealed that the software installed as part of the industrial scanner is more effective for analyzing knots (77.78% vs. 70.37%), sapwood (100% vs. 80%), and ambrosia wood (60% vs. 20%), while the software derived from the project is more effective for analyzing cracks (70% vs. 65%), ingrown bark (42.86% vs. 28.57%), and wood rays (81.82% vs. 27.27%).

Climate and local water availability are major evolutionary drivers of adaptive variation and plasticity in the hydraulic architecture of Tropical Montane Cloud Forest (TMCF) tree species. Between‐year xylem vessel variability is key to understanding the adaptation potential of wood anatomy of trees to drought. How wood anatomical features have been influenced by the typical TMCF climate and how tree species persist in these environments remain open questions, particularly in the context of predicted extreme climate events in the future.Here, we evaluated the effects of changes in temperature, precipitation and evapotranspiration during drought events on ring‐width and anatomical vessel traits (hydraulic diameter, vessel density, vessel grouping index and vulnerability index) for two relict endemic and threatened oak species (Quercus delgadoana and Q. meavei) from a Mexican TMCF.The study species differed in their functional and ecological vessel anatomical traits, and their wood anatomical differences are related to specific environmental requirements. However, the ring‐width indices (RWIs) calculated for these species indicate that both have high resistance and recovery, and thus high resilience to drought events.Ring‐width and vessel functional traits show differences in the between‐year variability of xylem traits associated with the hydraulic efficiency of these oak species, which is crucial to understanding how they avoid drought‐induced embolism and cavitation in vessel conduits. These results provide evidence for the existence of specific hydraulic systems that determine functional wood anatomy in response to climatic variation and drought in the study species. Further research assessing the wood anatomical adaptation to different climatic variables and identifying the xylem functional traits that underlie these adaptations, along with the mechanisms allowing tree species persistence in these environments, is essential to gain insight into the responses of TMCF to future drought events. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This paper deals with the determination of selected fire properties of oak wood, i.e., charring rate, which is used in practice to model and investigate the fire causes. Thermal loading was carried out using a measuring apparatus described in Utility Model No. 9373 registered by the Industrial Property Office of the Slovak Republic. Oak wood samples with dimensions of 40 × 50 × 50 mm (l × w × t) were thermally loaded by a heat flux of 15, 20, 25 and 30 kW·m-2, using a ceramic infrared heater. Two methods of determination of the charring rate, based on reaching the temperature of 300 ⁰C in individual depths in a specific time and according to the thickness of the charred layer formed in a time interval of 1800 s measured using a caliper were compared. Both methods confirmed that the charring rate is increasing with increasing thermal loading. The charring rate determined based on the temperature of 300 ⁰C ranged from 0.65 to 0.88 mm·min-1 . According to the second method, the charring rate reached values from 0.41 to 0.86 mm·min-1 . More accurate results were achieved by applying the method of determination of the charring rate based on the charred layer measured by a caliper. However, the method of determination of the charring rate using thermocouples can be considered less subjective because the temperature is measured automatically, using thermocouples compared to manual measurement using a caliper. The obtained results can be used as input data for computersupported modeling of indoor fires. [ABSTRACT FROM AUTHOR]

Summary: Barrel ageing is a critical process in wine industry since it produces substantial changes in the chemical composition of wines. The transfer of polyphenols from wood to wine would be influenced by various factors including wood characteristics and storage conditions. The role of the wine matrix in the extraction/modification of polyphenols during wine ageing has been scarcely studied. The objective of this study was to characterise and compare the phenolic composition of six varietal wines (Carménère, Cabernet Franc, Malbec, Petit Verdot, Sangiovese and Tempranillo) during ageing in a single type of oak barrel aiming to learn about the role of the variety on the ageing process. Wine sampling was performed at 3‐month intervals for 1 year. Polyphenol profiles were analysed using spectrophotometric and HPLC‐DAD methods. The study showed that the effect of oak wood ageing on the phenolic composition of wines is highly influenced by the grape variety. Thus, different polyphenol‐associated chemical parameters of oak‐aged wines would be affected by chemical properties of the varietal wines that are present prior to barrel ageing. [ABSTRACT FROM AUTHOR]

The qualitative spirit ageing bouquet, developed during maturation in oak casks through a complex transformation process, can result in a broad palette of nuances where roasted and nutty aromas are often identified. Nitrogen heterocycles (pyrazines, thiazoles, pyrroles), produced during the heating step of the barrel‐manufacturing, contribute to the perception of these nuances. However, their specific sensory characteristics within the spirit matrix have been poorly studied until now. The current study consisted in an overall olfactory characterization of nine targeted N‐heterocycles molecules previously identified in oak wood and detected in spirits. In a first step, the olfactory perception thresholds (detection and recognition) were measured in a spirit model medium (23% hydroalcoholic solution, pH 4), revealing that the presence of ethanol at such level minimally affected the olfactory perception of the studied compounds. A first sensory description of the set of N‐heterocycles also highlighted a large spectrum of aromatic nuances, mostly related to the semantic field of wood (nut, roasted, smoky, spicy). In a second step, a profile of the key aromatic attributes of the studied molecules was compiled, on the basis of their corresponding intensity scores given by a trained expert panel. Principal Component Analysis followed by Hierarchical Cluster Analysis categorized the pool of N‐heterocycles according to their sensory similarities. The presence of ethanol in spirit model matrix did not affect detection and recognition thresholds of studied N‐heterocycles. Wood‐derived nuances accounted among the most representative aromas characterized the studied N‐heterocycles. Functionals groups carried out by the chemical ring modified the aromatic perception of N‐heterocycles. [ABSTRACT FROM AUTHOR]

Understanding the development of whisky aroma during maturation in oak casks provides a rational basis for improvements in product quality. While oak wood is an important contributor to the spicy, toasted, and smoky aromatic notes, limited studies have focused on its role in the floral and mint notes of matured whiskies. However, achieving consistent flavour profiles remains difficult since the odorant molecules are mostly present in low concentration. A semi-preparative ultra-high performance liquid chromatography (UHPLC) method was applied to whisky and oak wood extracts and used to isolate fractions characterised by floral and mint aromas. To investigate the contribution of terpenoids in floral and fresh fragrances, a similar analytical process was applied to solutions of targeted reference compounds. This approach, coupled with gas-chromatography/mass-spectrometry analysis, indicated the presence of terpenoids in the fractions of interest together with selective separation according to chemical structure (i.e., monoterpenes, monoterpenols, ketone monoterpenes, and C13-norisoprenoids). This approach resulted in the detection of, ten and seven new terpenoids in whisky and oak wood. To the best of our knowledge, piperitone, mintlactones, and β-damascone are reported for the first time in whisky and oak wood. Even though raw material, fermentation and distillation processes largely contribute to the presence of terpenoids in new make spirit, this study provides evidence that oak wood enhances floral and mint notes in whisky through chemical and sensory interactions taking place during maturation. [ABSTRACT FROM AUTHOR]

This study analysed the bonding mechanisms and strength between wood and non-wood implants in producing laminated oak-wood beams. The suitability of different types of adhesives, namely for load-bearing and general purpose, was also analysed. Three different types of non-wood implants—carbon fibres, glass fibres, and aluminium were glued with epoxy resin (ER), thermoplastic 1-k polyurethane adhesives (PUR), structural polyurethane adhesives (PUR 2 and PUR 3), and polyvinyl acetate (PVAc) adhesives and bonds were tested for shear strength (SS) according to ISO 6238:2018. Results of the bond quality expressed as the ultimate load to failure and displacement were recorded using the universal mechanical testing machine in combination with the digital image correlation (DIC) method. Before the shear test, all the samples were conditioned in dry and wet climatic conditions. Test results indicated that the application of PUR adhesives for bonding carbon and glass fibres with oak wood could sufficiently replace two-component ER, which is generally recommended for such purposes but is very challenging to utilise in industrial conditions. PVAc adhesives proved efficient only for combination with AL implants and in dry conditions. Aluminium sheets were shown to require surface pre-treatment, such as sanding and degreasing or a different type of adhesive to achieve sufficient adhesion. [ABSTRACT FROM AUTHOR]

The work investigates the effects of CO2 laser parameters (laser power and raster density) on wood mass loss in oak wood and impacts on its morphology, chemical structure, and surface properties (colour and hydrophilicity). The energy amount supplied onto the wood surface with a laser beam under different combinations of the irradiation parameters was expressed through a single variable—total irradiation dose. The mass loss was confirmed as linear-dependent on the irradiation dose. With the mass reduction, the roughness was enhanced. The roughness parameters Ra and Rz increased linearly with the mass loss associated with the increasing irradiation dose. The FTIR (Fourier transform infrared spectroscopy) spectroscopy also detected chemical changes in the main wood components, influencing primarily the wood colour space. Conspicuous discolouration of the engraved wood surface was observed, occurring just at the minimum laser power and raster density. The additional increasing of laser parameters caused a novel colour compared to the original one. The detected dependence of wood discolouration on the total irradiation dose enables us to perform targeted discolouration of the oak wood. The engraved surfaces manifested significantly better wettability with standard liquids, both polar and non-polar, and higher surface energy values. This guarantees appropriate adhesion of film-forming materials to wood. Identification of the changes in wood surface structure and properties, induced by specific CO2 laser-treatments, is important for obtaining targeted discolouration of the wood surface as well as for the gluing or finishing of the surfaces treated in this way. [ABSTRACT FROM AUTHOR]

The blending of wine spirits (WSs) produced in different ageing conditions is a key operation to impart specific features, enhance complexity, increase the final product's quality and ensure brand consistency over the years, but requires time, labour and experienced blenders. This work aimed to develop a novel technology, natural blending, towards innovation and a more sustainable production process, adding value to the final product. WSs were aged in 250 L barrels and in 1000 L stainless steel tanks with wood staves and micro-oxygenation (MOX), using Limousin oak and chestnut wood simultaneously at a 50:50 ratio (natural blending) and separately; after 18 months of ageing, the last ones underwent the blending operation at the same ratio. All WSs were bottled and thereafter the following traits were analysed: alcoholic strength, acidity, dry extract, total phenolic index, low molecular weight compounds by HPLC method, chromatic characteristics and sensory profile. No significant differences in the physicochemical characteristics and sensory profile between the WSs resulting from the two blending technologies were found. Natural blending did not induce changes in the characteristics imparted by each ageing technology. These findings point to natural blending as a reliable alternative to the blending operation, especially in combination with ageing in tanks with staves and MOX. [ABSTRACT FROM AUTHOR]

Barrel aging is a crucial stage that influences the taste of wines and spirits, particularly increasing their sweetness and bitterness. This increase is caused by nonvolatile compounds released from oak wood. To search for such molecules, we performed a taste-guided inductive fractionation protocol using several analytical techniques. By using HRMS and NMR, two new galloylated derivatives were elucidated. Their enzymatic hydrolysis revealed the formation of β-methyl-γ-octalactone, indicating that they are potential precursors. The taste properties of these isomers revealed a sweet and bitter taste for P-WL-1 and P-WL-2, respectively. An LC-HRMS quantification method was performed to evaluate the influence of aging parameters such as botanical origin and toasting process on their concentrations. Several spirits were also analyzed to confirm their presence in this matrix. These results improve the understanding of the molecular markers responsible for the taste of beverages.

This study determined the impact of undertaking an initial treatment of oak wood by sealing its surface pores with epoxy resin, focusing on the durability of transparent coating systems when exposed outdoors. Throughout the exposure period, various parameters including color, gloss, surface wettability, and both macroscopic and microscopic surface evaluation were continuously monitored. The study involved two sets of samples: one set underwent the pretreatment, while the other did not. Subsequently, four coating systems were applied to the samples, comprising two solvent-based and two water-based coatings. The experiment was conducted over a period of two years, utilizing natural weathering methods within the premises of the Czech University of Life Sciences in Prague. The pretreatment with epoxy resin exhibited enhanced durability for all paint systems. The analysis showed a significant difference in gloss and color after 12 months of weathering exposure without any significant effect on surface wettability and sealing. However, after 24 months of the weathering exposure, no significant differences between the sealed and unsealed surface were observed. The most significant change in properties was noted for the water-based coatings used in coating systems number 3 and 4, and these coatings were rated as the best.

A methodology for measuring bandsaw tooth wear is presented in this paper. This type of measurement is proposed as an alternative way of determining tooth wear in industrial conditions. The method is based on determining the KE value, i.e., the distance of the radius of the rounded cutting edge of the tooth and the intersection of the surface of the back and the surface of the face of the cutting wedge of the bandsaw tooth. The rate of wear of bandsaw teeth is determined by comparing the measured value with the KE values given in the literature. During the development of the methodology, experimental cutting tests were performed at a sawmill that specializes in the production of floors from multi-layer glued laminated wooden boards. The investigated band saw was applied in the sawing process of oak (Quercus L.) boards. The average moisture content of the wood was MC = 32.9% when using the "wet" technology of lamella production. Since the monitored wear values are not very high, the use of certified measuring instruments is strongly recommended. [ABSTRACT FROM AUTHOR]

This study evaluated within-stem differences in the moisture content of stored summer-harvested oak wood with respect to drying method. The felled oaks were naturally dried for eight weeks, from 4 July to 29 August 2017. We analyzed two methods of preparation and storage: a transpiration drying method (W), and an air-drying method for stem-wood (L). Transpiration drying is a better method for oak stems than air-drying. Statistically significant differences between drying methods were found after six weeks of storage. This coincided with complete wilting of the leaves. However, signs of wilting and leaf color change appeared earlier, between the second and fourth weeks of storage. In parallel, in scenario W, a statistically significant difference in MC of sapwood was observed between the second and fourth weeks of storage. Such a phenomenon was not observed in scenario L. The MC of heartwood also gradually decreased, especially in scenario W. Explanation of this phenomenon lay outside the scope of this study; however, it indicates how the structure and properties of wood, in addition to storage conditions and methods, influence the efficiency of biomass drying in the harvesting area. [ABSTRACT FROM AUTHOR]

The article begins with a promising method of obtaining liquid extracts using electromagnetic radiation. The main advantages over traditional method of extraction are highlighted. Usage of oak wood in industry is listed briefly. The article also defines the main medical properties of oak wood components, promising usage of liquid oak wood extracts in winemaking industry is provided. The trend in extraction technologies has been determined which consists in the transition to intensive and promising methods, and their main principles are also indicated. The main factors determining the transition to new extraction methods have been identified. The article identifies the main problems of the production of cognacs during aging, which affect the price of the final product. The authors indicated the key components of oak wood, which form a taste and aroma in cognacs and brandy. The scientific and technical contradictions of the extraction and aging processes were formulated, and a hypothesis for their solution was proposed. The experimental stands on which the research was conducted are presented. All parameters at which the experiments were performed are specified. The thermograms of the processes are presented and it is determined that the lowest temperature is observed in the circulating MW extractor. From the analysis of the data on the concentration of dry matter, it was determined that the best indicators belong to the circulating MW extractor, where a water-alcohol solution with a higher concentration of alcohol was used as the extractant. The data on the rate of extraction of dry matter confirm the high efficiency of the circulating extractor. The data analysis also confirms that better effect of mechanodiffusion was detected in the circulating MW extractor. Conclusions have been made regarding the possibility of introducing such devices into production. [ABSTRACT FROM AUTHOR]

The work investigates the effects of CO2 laser parameters (laser power and raster density) on wood mass loss in oak wood and impacts on its morphology, chemical structure, and surface properties (colour and hydrophilicity). The energy amount supplied onto the wood surface with a laser beam under different combinations of the irradiation parameters was expressed through a single variable—total irradiation dose. The mass loss was confirmed as linear-dependent on the irradiation dose. With the mass reduction, the roughness was enhanced. The roughness parameters Ra and Rz increased linearly with the mass loss associated with the increasing irradiation dose. The FTIR (Fourier transform infrared spectroscopy) spectroscopy also detected chemical changes in the main wood components, influencing primarily the wood colour space. Conspicuous discolouration of the engraved wood surface was observed, occurring just at the minimum laser power and raster density. The additional increasing of laser parameters caused a novel colour compared to the original one. The detected dependence of wood discolouration on the total irradiation dose enables us to perform targeted discolouration of the oak wood. The engraved surfaces manifested significantly better wettability with standard liquids, both polar and non-polar, and higher surface energy values. This guarantees appropriate adhesion of film-forming materials to wood. Identification of the changes in wood surface structure and properties, induced by specific CO2 laser-treatments, is important for obtaining targeted discolouration of the wood surface as well as for the gluing or finishing of the surfaces treated in this way.

The present paper studied wood-water relations and their effects on color changes. Additionally, FTIR analysis of recent and archaeological oak wood was completed. Comprehensive knowledge of wood-water relations in recent and archaeological oak wood will facilitate the use of treatment material in the restoration and conservation process of the investigated artefacts. Wood samples were impregnated with tetraethyl orthosilicate. Sorption time until equilibrium moisture was reached increased significantly as a result of the treatment. Thus, the saturation time for treated recent oak wood was 43% longer than it was for untreated recent oak. Additionally, the treatment increased sorption time to equilibrium moisture in archaeological oak by 63%. The treatment resulted in significant color changes for both recent and archaeological oak wood. Samples displayed less color difference when they were dry compared to when they were wet. According to the FTIR analysis, tetraethyl orthosilicate causes the increase of the amount of O-H groups in archaeological oak wood and also caused an increase in the of the amount of C=O groups. This change is due to the hiding effect of xerogel formation on the functional group of wood. [ABSTRACT FROM AUTHOR]

The blending of wine spirits (WSs) produced in different ageing conditions is a key operation to impart specific features, enhance complexity, increase the final product’s quality and ensure brand consistency over the years, but requires time, labour and experienced blenders. This work aimed to develop a novel technology, natural blending, towards innovation and a more sustainable production process, adding value to the final product. WSs were aged in 250 L barrels and in 1000 L stainless steel tanks with wood staves and micro-oxygenation (MOX), using Limousin oak and chestnut wood simultaneously at a 50:50 ratio (natural blending) and separately; after 18 months of ageing, the last ones underwent the blending operation at the same ratio. All WSs were bottled and thereafter the following traits were analysed: alcoholic strength, acidity, dry extract, total phenolic index, low molecular weight compounds by HPLC method, chromatic characteristics and sensory profile. No significant differences in the physicochemical characteristics and sensory profile between the WSs resulting from the two blending technologies were found. Natural blending did not induce changes in the characteristics imparted by each ageing technology. These findings point to natural blending as a reliable alternative to the blending operation, especially in combination with ageing in tanks with staves and MOX.

Barrel-aging is one of the most influential unitary operations in wine-making that impact on the chemical and sensorial features of wines. High commercial value and short service life of barrels have stimulated the development of alternative products that allow barrel-reuse. In this study the effects of barrel scraping, addition of "ZigZag" inserts and addition of "BarrelStave" inserts on the phenolic composition (HPLC analysis and sensory assessment) of a Carménère wine were compared with one another. Wines aged in new barrels or in "ZigZag"-fitted or in barrels inserted with "BarrelStaves" showed similar higher contents of vanillic acid, vanillin, ellagic acid and ellagitannins compared to wines aged in either used or scraped barrels. The latter two wines showed higher flavanol contents. However, the observed differences in the phenolic profiles of wines between the various treatments were attenuated or suppressed towards the end of the study. Sensorially, wines aged in new barrels stood out for differential olfactory and taste intensities. Wines aged in new barrels or in "ZigZag"-fitted used barrels were similarly preferred by tasters, thus supporting the use of alternative oak wood renewers to extend the lifespan of barrels. [Display omitted] • Short service life of barrels have stimulated the use of alternative oak products. • Barrel scraping and addition of oak inserts on Carménère wine phenolics was studied. • Wines in new barrels or with inserts showed similar contents of several phenolics. • Wines with ZigZag or BarrelStaves inserts showed higher flavanol contents. • Wines aged in new barrels stood out for differential olfactory and taste intensities. [ABSTRACT FROM AUTHOR]

This study evaluated within-stem differences in the moisture content of stored summer-harvested oak wood with respect to drying method. The felled oaks were naturally dried for eight weeks, from 4 July to 29 August 2017. We analyzed two methods of preparation and storage: a transpiration drying method (W), and an air-drying method for stem-wood (L). Transpiration drying is a better method for oak stems than air-drying. Statistically significant differences between drying methods were found after six weeks of storage. This coincided with complete wilting of the leaves. However, signs of wilting and leaf color change appeared earlier, between the second and fourth weeks of storage. In parallel, in scenario W, a statistically significant difference in MC of sapwood was observed between the second and fourth weeks of storage. Such a phenomenon was not observed in scenario L. The MC of heartwood also gradually decreased, especially in scenario W. Explanation of this phenomenon lay outside the scope of this study; however, it indicates how the structure and properties of wood, in addition to storage conditions and methods, influence the efficiency of biomass drying in the harvesting area.

This article presents an attempt to estimate the nonlinear, multivariable dependence between the main (tangential) cutting force (FC) and the processing parameters and moduli of elasticity of oak wood (Quercus robur) during peripheral milling with a straight edge. The analysis indicated that the tangential force (FC) was affected by cutting depth (cD), feed rate per tooth (fZ), rake angle (γF), elastic modulus by stretching along the grain (ESA), elastic modulus by stretching perpendicular to the grain (ESP), elastic modulus by compression along the grain (ECA), and the elastic modulus by compression perpendicular to the grain (ECP). It was found that the elastic moduli (ESA, ESP, ECA, ECP) very well described the mechanical properties of processed wood. Several interactions between the examined parameters (namely, ESA·γF, ESP·γF, ECP·γF, fZ·γF, and fZ·cD) were confirmed in the developed relationship FC = f(ESA, ESP, ECA, ECP, fZ, cD, γF). [ABSTRACT FROM AUTHOR]

New and perspective method of extraction with usage of electromagnetic field is reviewed. The article provides advantages of using extraction in electromagnetic field over traditional methods of extractions. The main problem of traditional extraction technologies are retrieval incompleteness of targeted components and duration of the process. The article considers possibilities and perspectives of using oak wood extracts in different industries. The main scientific and technical contradiction of extraction was formulated. New hypothesis of extraction in electromagnetic field was proposed. The article provides methodology of experimental research, detailed description of devices which were used in the study and parameters of conducted experiments where water was used as extractant. Thermograms, changing of light transmission index and electricity consumption of all five series of experimental research are given in the article. Concentration comparison of dry matter in final extracts are given. The series of experimental research of extraction of oak wood using ethyl alcohol as extractant were also conducted, the parameters of research, thermograms, changing of light transmission index, electricity consumption and comparison of concentrations of dry matter are represented in the article. Article offers new innovative technology of highly extractive wines based on usage of microwave technologies and oak wood as an alternative to wines aging in oak barrels. Short organoleptic descriptions of obtained extracts and wines are given. The hypothesis about obtaining polyextracts by using polar extractants in electromagnetic field was proved. The mechanodiffusion effect was confirmed. It was confirmed that extraction of targeted components in MW extractors is 2,5…5 times higher than in traditional methods of extraction, energy consumption is 1,5…2 times lower than in traditional ones. It was defined that film and circulating extractors have advantages in obtaining high quality polyextracts from oak wood with higher rate of extraction of targeted components and have perspectives of industry application [ABSTRACT FROM AUTHOR]

A lot of research has been done related to the influence of different machining factors on the wood machining process. Methodologically, the factors are divided into three main groups that affect cutting mechanics: factors associated with material properties, factors that are dependent on the cutting tools, and factors attributed to the cutting process itself. A better understanding of machining factors could be the foundation for predicting the behavior of the material in the machining process. Also, it may consequently contribute to a more efficient and economical machining outcome and above all, the better quality of the machined surface. One of the basic parameters of cutting mechanics is cutting forces. There are various models in literature for determining the dependence of values of cutting forces on the selected impact factors. Different cutting force models are analyzed and compared in this paper. The results performed in the peripheral milling parallel with wood grains of oak wood (Quercus robur) were used for testing the models. The analysis of these models indicated that there is no match between the calculated and the experimental results, but there is a similarity in the form of the curve. Changes in the measured values are accompanied by corresponding changes in the calculated values, which indicates that these models can find application in real cutting conditions. [ABSTRACT FROM AUTHOR]

Ellagitannins are signature constituents of oak wood and their consumption has been associated with various health benefits. In vivo, they undergo metabolic degradation including gut microbial metabolism yielding urolithins. Only limited data is available about compounds being present in blood after intake of an extract from French oak wood, Robuvit®. In the course of a randomized, double-blind, controlled clinical investigation, 66 patients undergoing hysterectomy received placebo or 300 mg Robuvit® per day before and over 8 weeks after surgery. Serum and blood cell samples were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The number of urolithin producers and the urolithin levels increased after intake of Robuvit®. In serum samples, the median concentration of urolithin A was 14.0 ng/ml [interquartile range (IQR) 57.4] after 8 weeks. Urolithin B was determined at 22.3 ng/ml (IQR 12.6), urolithin C at 2.66 ng/ml (IQR 2.08). In blood cells, lower concentrations and only urolithins A and B were detected. A statistically significant association of lower post-surgical pain scores with metabotype A was detected (p < 0.05). To conclude, supplementation with French oak wood extract raised urolithin generation in patients and suggested health advantages for urolithin-producers.

This paper examines the effect of selected factors on the wood bonded joint strength. The structural factor under scrutiny was the geometry of the surface area; however, other major dimensions of adherends were compared as well. The tests were performed on 6 joint types: butt, v-shaped, interlocking, scarf, tongue & groove, and single lap joints, which were formed on two types of substrate materials – pine and oak wood, and adhesively bonded. The joints were bonded with Prefere 6312 wood adhesive and Loctite 3430 two-component epoxy adhesive. Strength testing of the joints was performed on Zwick/Roell Z150 material testing machine, according to DIN EN 1465 standard. The results obtained from the tests indicate that bonded joints of oak wood exhibit higher strength properties than those of pine wood adherends, which was confirmed in nearly all strength tests.

Haloanisoles are responsible for musty or mouldy off-flavours in wine. These molecules are extremely odorous and they alter wines in an irreversible way. The origin of haloanisoles can be attributed to the biodegradation of halophenols, which can be found in winery environments. Various materials including oak products (wood tanks, barrels, chips, staves) may be contaminated by haloanisoles and halophenols. Once polluted, these materials may release these molecules into wine. Requests for analyses of haloanisoles and halophenols in oak wood have gradually increased in recent years, above all from the coopers, who want to prove the quality of their products. However, the lack of an official testing method is an obstacle for the performance monitoring of laboratories. In response to these challenges, BIPEA organises, since October 2013, regular proficiency-testing schemes (PTS) for the detection and quantification of these molecules in oak wood. For each test, the statistical treatment of laboratories' results is performed according to ISO 13528. These PTS enable the participating laboratories to compare with each other, draw up a general inventory of their analytical skills and improve their performances for the detection and quantification of haloanisoles and halophenols in oak wood. [ABSTRACT FROM AUTHOR]

This study focuses on characterization of the fuel properties of chimney soots that arise from incomplete combustion of carbonaceous fuels. For this, soots from oak woods were collected from the chimneys of a residential stove as well as a bakery furnace. Also, lignite soot was taken from a residential coal burning stove' chimney, and the soot of diesel fuel was taken from the exhaust pipe of a light commercial vehicle. These soots were analyzed via proximate analysis, particle size distribution, non-isothermal burning characteristics, morphology, mineralogy, and functional groups. It was found that soots carried a great deal of calorific value and the properties of these soots differed seriously depending on the source. The presence of particles < 2.5 µm (PM2.5) was detected for the soots of oak wood and lignite. Burning characteristics including the burning reactivity and the ignition points were also found to be affected by the volatile matter and ash yields of the soot samples. That is, the highest burning reactivity belonged to oak wood's soot, while the diesel fuel's soot showed low burning reactivity and it burned steadily. Besides, it was concluded that all of the soots have highly oxygenated structures in both organic and inorganic parts that affect their fuel properties. [ABSTRACT FROM AUTHOR]

Inhomogeneities in wood and wood products are evident. Sometimes these inhomogeneities are combined with other inhomogeneities such as drilling. Each can have different effects on dynamic properties, and these footprints can cause hidden defects in wood and wood products. In this research, the effects of artificial inhomogeneity of density and drilling diameters (1 mm, 3 mm, 5 mm, and 10 mm) on dynamic properties of the beams produced from oak wood jointed with poplar blocks (one at the end and the other at the central part of the beam) were investigated. Free vibration on a free-free beam test was subjected for the evaluations. The results indicated that factors such as dynamic modulus of elasticity, acoustic coefficients, and damping capacity, were affected by both inhomogeneity and drillings. The acoustical converting efficiency showed the exact location of inhomogeneity. It also showed the level of drilling diameter. [ABSTRACT FROM AUTHOR]

Two-dimensional proton nuclear magnetic resonance (2D 1H NMR) relaxometry is increasingly used in the field of wood sciences due to its great potential in detecting and quantifying water states at the level of wood constituents. More precisely, in this study, this technique is used to investigate the changes induced by "natural" and "artificial" aging methods on modern and historical oak woods. Two bound water components are detected and present differences in terms of association to the different wood polymers in cell walls: one is more strongly associated with wood polymers than the other. The evolution of the two bound water types is discussed in regard to aging methods and is related to the structure of the cell wall, especially with the S2 layer and the evolution of wood chemical composition (cellulose, hemicelluloses and lignin). The evolution of hydric strains is also discussed taking into account the effect of aging methods on the two bound water components. The obtained results confirm the ability of 2D 1H NMR relaxometry to evaluate the effect of aging at the molecular level and on hydric deformation. Furthermore, this method shows that it is possible to determine the moisture content of wood without the necessity to oven-dry the wood material. [ABSTRACT FROM AUTHOR]

Various chemical and physical barrel sanitization methods were evaluated in terms of their effect on oak volatiles in situ. A gas chromatography–mass spectrometry (GC–MS) method using a programmable temperature vaporizing (PTV) injector in solvent-split mode was developed and validated for the analysis of oak volatiles extracted in aqueous acetone. Results revealed that barrel sanitization methods affected oak volatile compounds and that the degree of modification depended on the type of sanitization method and the duration or concentration of the applied treatment. Sanitization predominantly lowered concentrations of oak volatiles when hot water treatment at 80 °C, steam, ethanol treatment, and a 200 ppm peracetic acid treatment were applied. Gaseous sulphur dioxide, aqueous ozone, and hot water treatment at 60 °C, however, had no significant effect. This work provides the first direct comparison of an array of barrel sanitization methods in relation to their impact on desirable oak volatile compounds. [ABSTRACT FROM AUTHOR]

Ellagitannins are signature constituents of oak wood and their consumption has been associated with various health benefits. In vivo , they undergo metabolic degradation including gut microbial metabolism yielding urolithins. Only limited data is available about compounds being present in blood after intake of an extract from French oak wood, Robuvit®. In the course of a randomized, double-blind, controlled clinical investigation, 66 patients undergoing hysterectomy received placebo or 300 mg Robuvit® per day before and over 8 weeks after surgery. Serum and blood cell samples were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The number of urolithin producers and the urolithin levels increased after intake of Robuvit®. In serum samples, the median concentration of urolithin A was 14.0 ng/ml [interquartile range (IQR) 57.4] after 8 weeks. Urolithin B was determined at 22.3 ng/ml (IQR 12.6), urolithin C at 2.66 ng/ml (IQR 2.08). In blood cells, lower concentrations and only urolithins A and B were detected. A statistically significant association of lower post-surgical pain scores with metabotype A was detected (p < 0.05). To conclude, supplementation with French oak wood extract raised urolithin generation in patients and suggested health advantages for urolithin-producers. [ABSTRACT FROM AUTHOR]

The paper deals with the assessment of the age of oak wood (0, 10, 40, 80 and 120 years) on its fire resistance. Chemical composition of wood (extractives, cellulose, holocellulose, lignin) was determined by wet chemistry methods and elementary analysis was performed according to ISO standards. From the fire-technical properties, the flame ignition and the spontaneous ignition temperature (including calculated activation energy) and mass burning rate were evaluated. The lignin content does not change, the content of extractives and cellulose is higher and the content of holocellulose decreases with the higher age of wood. The elementary analysis shows the lowest proportion content of nitrogen, sulfur, phosphor and the highest content of carbon in the oldest wood. Values of flame ignition and spontaneous ignition temperature for individual samples were very similar. The activation energy ranged from 42.4 kJ·mol−1 (120-year-old) to 50.7 kJ·mol−1 (40-year-old), and the burning rate varied from 0.2992%·s−1 (80-year-old) to 0.4965%·s−1 (10-year-old). The difference among the values of spontaneous ignition activation energy is clear evidence of higher resistance to initiation of older wood (40- and 80-year-old) in comparison with the younger oak wood (0- and 10-year-old). The oldest sample is the least thermally resistant due to the different chemical composition compared to the younger wood.

Adega do Casal Manteiga is a winery, publicly owned by the Municipality of Oeiras that produces Carcavelos fortified wine. Carcavelos fortified wine is an appellation of origin and demarcated as D.O.P. (Denominação de Origem Protegida). This study examines the effects of barrels made from botanical species (Quercus pyrenaica, and Quercus robur) and toasting method (medium and high) on a single vintage wine that has been aged for 8 years. Twenty barrels were used, with five replicates for each factor. The barrels were fabricated and toasted using the same cooperage, J.M. Gonçalves in Portugal. Significant differences were seen between the species Q. robur and Q. pyrenaica, with an impact on total phenolic content, including both flavonoids and non-flavonoids. The total phenols of the wine aged in Q. pyrenaica barrels was significantly higher than in the Q. robur barrels, and Q. pyrenaica contained more flavonoids than Q. robur in medium and high toast barrels. Q. pyrenaica showed more non-flavonoid compounds than Q. robur inhigh and medium toasted barrels, but this difference in non-flavonoids was only statistically significant in the high toasted barrels. The degree of toasting had significant effects on the flavonoid content of the wine, as well as the tanning power. Flavonoid content increased for both Q. pyrenaica and Q. robur in the wines that were aged in high tasted barrels compared to those that were medium toasted. The tannin power decreased for both Q. pyrenaica and Q. robur when the toasting increased.

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has been evaluated using Raman and attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopies, and their main spectral features have been linked to phenolic compound extractabilities, as measured by classic chemical analyses. To support the analysis, microscopic images of the samples were also recorded using scanning electron microscopy (SEM). The applied methodology is shown to be useful to relate the wood cell wall structure to phenolic extractability levels of wood samples. It could assist in selecting oak wood suited for improving wine quality with regard to its color or/and stability through the addiction of external copigments to wine. [ABSTRACT FROM AUTHOR]

This study presents a semi-conductor metal oxide gas sensor system for the online flue gas monitoring during oak wood drying. Oak wood flakes and solid oak wood were heated on laboratory scale. The emissions were analyzed by gas chromatography–mass spectrometry and monitored by a semi-conductor metal oxide gas sensor setup. The calibrated sensor system was able to detect different drying and degradation stages of the oak wood flakes by online monitoring acetic acid and furans/methoxyphenols at 25–240 °C. The system also allowed a monitoring of acetic acid emission from solid wood at 75 °C. This sensor application has the potential to online monitor the flue gas of oak lumber drying and optimize the drying process. [ABSTRACT FROM AUTHOR]

Abstract Wood has been extensively used as a material for different applications over the years, therefore the understanding of different degradation processes in various environments is of great importance. In this study, the infrared spectroscopy, X-ray diffraction and chemometric methods were used to evaluate and compare the structure of archaeological and artificially degraded oak wood. The results clearly show that modifications in the structure of archaeological wood are related to the position of the material in the log (sapwood and heartwood), thus the extent of wood degradation. To identify the possible factors influencing these effects, the control wood samples were exposed to artificial white rot biodegradation with Coriolus (Trametes) versicolor and to alkali treatment (with NaOH solution). Due to the structural similarities between biodegraded wood and control or archaeological samples, this type of decay is likely to occur during natural ageing along with degradation produced by other environmental factors. Further, no real similarity was identified between the alkali treated wood and archaeological samples, indicating that such degradation does not affect wood under natural conditions. Graphical Abstract Unlabelled Image Highlights • Archaeological waterlogged and artificially degraded wood samples were analysed. • FT-IR spectroscopy, X-ray diffraction and chemometric methods were used to evaluate wood structure. • Structural modification of archaeological wood was related to its initial structure. • Differences between sapwood and heartwood of archaeological samples were observed. • Excessive depletion of carbohydrates was observed for sapwood archaeological sample. [ABSTRACT FROM AUTHOR]

Effects of material, tool, and technological parameters were assessed during planar milling of thermally modified spruce (Picea abies L.) and oak (Quercus cerris L.) wood relative to the energy intensity of machining. The milling took place under the following conditions: cutting speeds of 20 m/s, 30 m/s, and 40 m/s; feed rates of 4 m/min, 8 m/min, and 11 m/min; and rake angles of 15 °, 20 °, and 25 °. Another change factor was the temperature of the thermal modification (20 °C - reference; 160 °C; 180 °C, and 210 °C). Each factor (cutting speed, rake angle, temperature, and feed rate) was found to have a statistically significant effect. The change in cutting speed had the greatest effect. The lowest power consumption was achieved with a cutting speed of 20 m/s, feed rate of 4 m/min, and rake angle of 25 °. In terms of thermal modification, thermally modified wood was machined with a lower power input. This result can be explained by the chemical processes in the wood and the reduced density in comparison with untreated wood. In comparison with density, the influence of changes in wood chemical composition did not have as great an impact on power input. [ABSTRACT FROM AUTHOR]