Aged Wood Research Articles

Effect of Punica granatum peel and Melia azedarach bark extracts on durability of European beech and maritime pine

A method to improve wood durability using natural extracts was evaluated. Wood deterioration is a condition caused by several abiotic and biotic factors including fungal contamination. To date, approaches aiming at the reduction of these contaminants mainly involve the use of chemicals agents. Natural products could represent an alternative strategy. Aqueous extracts of Punica granatum L. (pomegranate) peel and Melia azedarach L. barks were evaluated as antifungal agents to improve natural durability of beech wood and maritime pine. To evaluate the effect of treatments under simulated accelerated ageing of wood by natural conditions, impregnation and leaching tests were performed. Results demonstrated that samples impregnated with pomegranate or M. azedarach solutions notably increased the biological resistance of wood in a dose-dependent manner. These results were confirmed by the reduction in weight losses in treated samples even after 6 weeks of fungal exposure. Moreover, after leaching tests, 20 and 7% (w/v) of pomegranate and M. azedarach extract solutions were demonstrated as the better concentrations to enhance wood durability. Total phenol content and characterization of the phenolic compounds in both, natural extracts and wood samples were analyzed by Folin–Ciocalteu assay and HPLC-DAD. In conclusion, it was demonstrated that the present method can be considered as an effective treatment to increase wood durability while it proposes the valorization of natural extractives in wood industry.

Temporal dominance of sensations, emotions, and temporal liking measured in a bar for two similar wines using a multi‐sip approach

AbstractEating and drinking are dynamic processes where both sensations and emotions might evolve or change over time during multiple bites/sips. However, most previous studies have measured food‐evoked emotions statically, that is, at a fixed time point after consumption and using a single bite/sip approach. This study aimed to explore the sensitivity of temporal dominance of sensations (TDS), of emotions (TDE), and temporal liking (TL), using a multi‐sip approach, to differentiate between two comparable tasting wines. A glass of wine, in an appropriate consumption context, a bar, was served to 69 consumers, in two different sessions. It was shown that TDS and TDE captured small differences between equally liked wines. Wines were distinguishable during consumption, based on the dominance of basic sensations such as acid, bitter, and dry, rather than aromatic sensations and based on three emotions pleased, comforted, and relaxed. These emotions were dominant in both wines and in all stages of consumption but differed in the dominance rates. So, the impact of wine consumption on emotions was more uniform during consumption while new sensations became dominant during drinking.Practical implicationsThe method tested in this study showed a sensitivity level sufficient to capture subtle but significant differences between similar, equally liked wines. Wines tested have a major difference in wine‐making process, that is, one of the wines had a particular wood aging processing in new oak barrels conferring specific flavors and associated costs. For the wine industry, the method can be particularly useful to understand to which extent consumers perceive differences in sensations and emotions, in a blind tasting, to investigate if increased costs of production are acceptable and justified. For other food products, the method can be useful to use during product development stage, when the aim is to differentiate prototypes with subtle differences in ingredients composition and associated costs. Knowing when certain sensations and emotions occur during consumption might help to create successful products in the market. Further research using different food or beverages is however necessary to assure its validity.

Fracture behaviour of historic and new oak wood

Recent museum studies have indicated the appearance of cracks and dimensional changes on decorated oak panels in historical Dutch cabinets and panel paintings. A thorough analysis of these damage mechanisms is needed to obtain a comprehensive understanding of the causes of damage and to advise museums on future sustainable preservation strategies and rational guidelines for indoor climate specifications. For this purpose, a combined experimental-numerical characterization of the fracture behaviour of oak wood of various ages is presented in this communication. Three-point bending tests were performed on historical samples dated 1300 and 1668 A.D. and on new samples. The measured failure responses and fracture paths are compared against numerical results computed with a finite element model. The discrete fracture behaviour is accurately simulated by using a robust interface damage model in combination with a dissipation-based path-following technique. The results indicate that the samples dated 1300 A.D. show a quasi-brittle fracture response, while the samples dated 1668 A.D. and the new samples show a rather brittle failure response. Further, the local tensile strength of the oak wood decreases with age in an approximately linear fashion, thus indicating a so-called ageing effect. Numerical simulations show that, due to small imperfections at the notch tip of the specimen, the maximal load carrying capacity under three-point bending may decrease by maximally 7 %. A comparison between a calibration of the experimental results by isotropic and orthotropic elastic models shows that the peak load is 10–13% higher for the orthotropic elastic model. Finally, no significant dependence of the fracture toughness on the age of the oak wood and on the orientation of the fracture plane has been found. The strength and toughness values measured can be used as input for advanced numerical simulations on climate-induced damage in decorated oak wooden panels and panel paintings.

Accelerated aging of pine wood waste/recycled LDPE composite

The production of composites from recycled thermoplastic polymers and natural fibers has been an interesting alternative to generate polymeric materials of low cost, with sufficient properties for application and environmentally adequate. The aim of the present study was to evaluate the effects of the accelerated photochemical aging on properties of a composite produced from recycled low-density polyethylene (LDPE) with pine wood waste (PWW) in the presence of coupling agent. The oxidation, performance of mechanical properties and surface changes of the LDPE and LDPE/PWW composite were monitored at different times of aging. It was observed that LDPE/PWW composite presented a higher resistance to the accelerated photochemical aging than unfilled LDPE, mainly due to the better performance of the mechanical properties of elongation at break and tensile strength, showing that the presence of natural fibers from PWW lead to the stabilization of the polymeric matrix of LDPE.

Fruit quality variability within the tree canopy

We studied intra-canopy fruit quality variability as a function of flowering time and the age of the bud wood in apple trained to the spindle system. The experiment was carried out on adult 'Gala' apple trees grafted on M.9 rootstock. Three trees were chosen for the experiment and on these all the flower clusters were labeled just before bloom. The initial and final date of the “king flower” opening were recorded and for each of these, fruit diameter and ripening stage were monitored during the growing season. Also, the age of the wood carrying each flower cluster was recorded. At harvest, fruit size, over color and quality traits were assessed. Fruit variability within the canopy was very large. Flower opening time had a strong influence on fruit size and ripening stage. The first flowers to open were immediately characterized by a higher growth rate of fruits. At harvest these fruits reached a bigger size, an early ripening stage and lower flesh firmness. Moreover, a short flowering length also induced an earlier ripening. In addition the bud wood age had an effect on fruit quality and the flowers carried on older wood had larger size fruits, characterized by an earlier ripening stage and lower flesh firmness at harvest. There were no differences in either over color or in soluble solids content in fruits produced by different flower clusters and bud wood ages.

UV-blocking properties of Zn/ZnO coatings on wood deposited by cold plasma spraying at atmospheric pressure

In this study, artificial ageing of beech wood coated with Zn/ZnO particles by means of a cold plasma spraying process as well as coating systems including a Zn/ZnO layer and additional conventional sealings were examined. As ascertained by colour measurements, the particle coatings significantly decreased UV light-induced discolouration. Even though no significant colour changes were observed for particle-coated and alkyd-sealed samples, ATR-FTIR measurements revealed photocatalytic degradation of the alkyd matrix. In contrast, the polyurethane sealing appeared to be stabilised by the Zn/ZnO coating. Furthermore, morphologic properties of the pure particle coatings were studied by SEM and roughness measurements. SEM measurements confirmed a melting and solidifying process during deposition.

Testing mechanical characteristics of chestnut stakes used in bed sills for stream restoration

Using of wood elements for constructing bed sills in Mediterranean streams, where the banks are not protected by tree vegetation, needs an evaluation of biological and mechanical characteristics for evaluating both the wood durability and the effectiveness of the stream restoration project. Very few studies have dealt both with the decay of mechanical characteristics of wood elements employed for stream restoration works and with the changes over time of physical and chemical wood characters. In this paper, for a wood and stone bed sill located in a stream having no shaded banks, the changes of physical and chemical characters detected after 12, 18, 24, 30, 36, 42 and 48 months on chestnut stakes are preliminarily recalled. Then, using three chestnut stakes extracted after 96 and 108 months and two unaltered stakes, as reference condition, the mechanical compression tests were carried out. The results of the compression tests for both runs (altered and unaltered stake) allowed to establish the influence of the ageing process on the compressive strength and stiffness of the chestnut wood. Finally, using two chestnut stake extracted after 108 and 120 months and two unaltered stakes, the flexural tests were carried out by a four points scheme (two supporting points and two loading points) according to UNI EN 408-2012 standard. The results of the flexural tests for both runs (altered and unaltered stake) allowed to establish that the wood ageing process determines the decay of mechanical strength of the material and reduces the bending strength of the chestnut wood. From an applicative point of view, the obtained results showed that after 10 years the mechanical resistance characteristics of the wood stakes are less than those corresponding to the undisturbed reference condition.

The effect of wood age on infection by <i>Neonectria ditissima</i> through artificial wounds on different apple cultivars

The age of apple wood may affect its susceptibility to European canker (Neonectria ditissima). Therefore, a glasshouse experiment was conducted with potted trees of six apple cultivars (‘Braeburn’, ‘Scilate’, ‘Fuji’, ‘Golden Delicious’, ‘Jonathan’ and ‘Royal Gala’) grafted onto two rootstocks (‘M793’ and ‘M9’) to study the effect of 3-, 2- or 1-year-old wood on incidence and disease progression following inoculation with conidia of N. ditissima. Initial analyses of cultivars on ‘M793’ showed a significant wood age effect on disease incidence and lesion length, which was similar to cultivars grafted on ‘M9’. Three-year-old wood developed more and longer lesions than either the 2- or the 1-year-old wood. A significant cultivar effect was observed with ‘Royal Gala’ developing more lesions than the other cultivars tested. More than half of asymptomatic wounds placed onto apple sap-amended water agar for pathogen isolation yielded N. ditissima.

Characterization of VOC emission profile of different wood species during moisture cycles

This study addresses the characterization of volatile organic compounds (VOCs) emitted by samples of 13 different wood species, belonging to both softwoods and hardwoods groups, regularly measured at different intervals of time, after the first measurement on green wood. The same wood specimens were subjected to several cycles of water desorption and adsorption, assuming that moisture variation might play a role in both the formation and emission of VOCs. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-TOF-MS) was used as a tool to characterize the emission of VOCs. Coupled with a multivariate class-modelling approach, this tool was able to discriminate between groups (softwood and hardwood) and in some cases between different species. However, results showed that the discriminant capacity of VOCs emission to separate species and families rapidly decreases after the first cycles of moisture variation in wood. The green wood was characterized by a richness of volatile compounds, whereas, after only the first dry cycle, wood emitted a more restricted group of compounds. We hypothesized that most of these VOCs might have originated from structural changes and degradation processes that involve the main polymers (particularly hemicellulose) constituting the cell wall of wooden cells. The results obtained are in agreement with the physical and chemical modification processes that characterize wood ageing.

Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.

The evolution of mineral composition and wine strontium isotopic ratio 87Sr/86Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87Sr/86Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87Sr/86Sr, not precluding the use of this parameter for wine traceability purposes.

An Approach to the Study of the Interactions between Ellagitannins and Oxygen during Oak Wood Aging.

During the aging of red wine in oak wood barrels, or in alternative aging systems, interactions between the compounds released from wood, the compounds of the wine, and oxygen can take place. The main objective of the present work was to study oxygen-ellagitannin interactions by monitoring their levels in three model systems, all containing the same amounts of French oak chips and differing only in the oxygen content: total absence, only the oxygen released from the chips, and air-saturated (model systems F, OW, and OS, respectively). This study has highlighted the influence of oxygen in the ellagitannins' evolution and the relevance of the oxygen trapped into the oak chips, reporting for the first time the kinetics of oxygen release to the model wine. Furthermore, the indirect contribution of oxygen to the ellagitannins' disappearance by boosting autoxidative reactions has also been pointed out. Vescalagin seems to be the ellagitannin most affected by the initial oxygen levels.

Large proportion of wood dependent lichens in boreal pine forest are confined to old hard wood

Intensive forest management has led to a population decline in many species, including those dependent on dead wood. Many lichens are known to depend on dead wood, but their habitat requirements have been little studied. In this study we investigated the habitat requirements of wood dependent lichens on coarse dead wood (diameter >10 cm) of Scots pine Pinus sylvestris in managed boreal forests in central Sweden. Twenty-one wood dependent lichen species were recorded, of which eleven were confined to old (estimated to be >120 years old) and hard dead wood. Almost all of this wood has emanated from kelo trees, i.e. decorticated and resin-impregnated standing pine trees that died long time ago. We found four red-listed species, of which two were exclusive and two highly associated with old and hard wood. Lichen species composition differed significantly among dead wood types (low stumps, snags, logs), wood hardness, wood age and occurrence of fire scars. Snags had higher number of species per dead wood area than logs and low stumps, and old snags had higher number of species per dead wood area than young ones. Since wood from kelo trees harbours a specialized lichen flora, conservation of wood dependent lichens requires management strategies ensuring the future presence of this wood type. Besides preserving available kelo wood, the formation of this substratum should be supported by setting aside P. sylvestris forests and subject these to prescribed burnings as well as to allow wild fires in some of these forests.

Influence of Chirality of Lactones on the Perception of Some Typical Fruity Notes through Perceptual Interaction Phenomena in Bordeaux Dessert Wines.

Recent studies concerning the aroma of noble rot dessert wines revealed the importance of a well-known phenomenon in perfumery, the perceptual blending, to create the perception of "overripe orange" nuances. Thus, compounds associated with both oak wood aging (3-methyl-4-octanolide and eugenol) and Botrytis cinerea development under the form of noble rot (2-nonen-4-olide and γ-nonalactone) contribute to a specific aroma of great noble rot dessert wines through perceptual interaction phenomena. This synthetic perception phenomenon was established from reconstitution, addition, and omission sensory experiments, using wine extract fractions supplemented with the volatile compounds previously mentioned. To better understand the sensory impact of these compounds, the goal of this research was to study the contributions of enantiomeric forms of 2-nonen-4-olide and γ-nonalactone and the diastereoisomers of 3-methyl-4-octanolide. After multidimensional chiral chromatography analysis, the relative proportions of enantiomers or diastereomeric forms were first established and then sensory experiments were carried out using the reference compounds with isolated fractions from dessert wines. A dominance of the R form was established for 2-nonen-4-olide, which was correlated with wine aging, while the S form is more dominant in young dessert wines. Furthermore, the reconstitution experiments confirmed perceptual interaction phenomena and revealed the sensory contribution of (R)-2-nonen-4-olide and cis-3-methyl-4-octanolide concerning the "overripe orange" nuances, whereas no sensory impact for the γ-nonalactone isomers was observed.

Effects of Ageing on the Color and Surface Chemistry of Paulownia Wood (P. elongata) from Fast Growing Crops

The behavior of paulownia wood (Paulownia elongata) was investigated using three different ageing tests: simulated natural ageing under the influence of light under indoor conditions, temperature-induced ageing in the dark, and UV-induced ageing. Ageing effects were evaluated by color measurements in the CIE Lab system. Simulated natural ageing of wood in indoor conditions (6 months) and UV-accelerated ageing (72 h) are complex and dynamic processes, which resulted mostly in yellowing of the samples due to photo-degradation. Temperature-induced ageing (288 h at 100 C) resulted mostly in a rapid and visible darkening of the paulownia wood. Comparative in-time evolution of color changes during accelerated UV ageing testing and simulated natural ageing testing under indoor conditions allowed the estimation of an acceleration index of about 50X. Fourier transform infrared spectroscopy (FTIR) was used to examine specific chemistry changes occurring during these ageing tests. UV light from natural or artificial sources caused primarily lignin degradation followed by oxidative processes leading to carbonyl-containing chromophores. Temperature-induced partial degradation of hemicelluloses and oxidative processes resulted in the formation of chromophores containing mostly conjugated carbonyl groups. This research highlighted that paulownia wood (P. elongata) is quite sensitive to ageing under the action of light and temperature, which cause notable color and surface chemistry changes.

Speed Dating: A Rapid Way to Determine the Radiocarbon Age of Wood by EA-AMS

AbstractRadiocarbon measurements in tree rings can be used to estimate atmospheric 14C concentration and thereby used to create a 14C calibration curve. When wood is discovered in construction sites, rivers, buildings, and lake sediments, it is unclear if the wood could fill gaps in the 14C calibration curve or if the wood is of historical interest until the age is determined by dendrochronology or 14C dating. However, dendrochronological dating is subjected to many requirements and 14C dating is costly and time consuming, both of which can be frivolous endeavors if the samples are not in the age range of interest. A simplified 14C dating technique, called Speed Dating, was thus developed. It can be used to quickly obtain 14C ages as wood samples are neither chemically treated nor graphitized. Instead, wood is combusted in an elemental analyzer (EA) and the CO2 produced is carried into an accelerator mass spectrometer (AMS) with a gas ion source. Within a day, 75 samples can be measured with uncertainties between 0.5–2% depending on the age, preservation, and contaminants on the material and Speed Dating costs about one-third of conventional AMS dates.

Radiocarbon Variation in Charcoal/Wood and Soil Fractions from a Loessic Setting in Central Alaska

AbstractThe Healy’s Lucky Strike site in central Alaska has an exceptional Holocene loess-paleosol sequence that has afforded us the ability to look at variation in14C dating of soil organic matter (SOM) fractions in a high-latitude loess setting. Our work has focused on comparing the radiocarbon ages of charcoal and wood to base-soluble humic acids (HA) and base-insoluble soil residue (SR) fractions from bulk soil samples. Charcoal/wood ages were younger than HA ages reflecting the later stages of vegetation development at the surface of the soils prior to being covered by loess accumulation; the HA ages generally reflect the overall timing of soil formation and mean residence time of SOM. Soil residue ages are older than charcoal/wood and HA ages. SOM ages at this location become increasingly older than charcoal/wood ages with depth, reaching 750 to 8070 yr in difference and associated with weakly developed soils at the lowest depths. We suggest the drastic SOM age differences at this site result from the differential incorporation of small particles of coal throughout the sedimentary matrices introduced older contaminants to SR fractions.

Centralized supply chain planning model for multiple forest companies

ABSTRACTIn this paper, we present a mathematical model to plan logistics activities in a forest products supply chain. In particular, a mixed-integer linear program is developed to maximize the total profit of the value chain, involving decisions related to the volumes of wood to harvest and to keep in stock, as well as the quantities to deliver to each business unit to meet market demand. The model also includes different constraints concerning fibre freshness across the network (forest, sawmills, and paper mill), as this has an effect on operation costs and supply decisions. Various scenarios based on the demand variation, price fluctuations, and wood aging levels are tested, followed by a sensitivity analysis. Results show that price and demand variations as well as fibre freshness are important criteria to consider in the procurement and production planning for increasing the forest supply chain benefits. The scenarios analysed also confirm the usefulness of the model in guiding companies to make adequate planning decisions according to their business environment.

Factors affecting fruit set and fruit quality along branch units of different apricot cultivars

ABSTRACTUnderstanding the differences in fruit quality within apricot tree canopies is necessary before developing strategies to reduce variation. Fruit set, fresh weight (FW) and soluble solids and dry matter concentrations (SSC, DMC) were lower, by up to 30%, 28 g, 2.4% and 2.5%, respectively, in fruit from 1-year-old long shoots and terminal spurs or from short shoots and spurs on 4-year-old wood, than on those from 2- and 3-year-old wood, for the six genotypes examined. Genotype, year and wood age affected mealiness, gel development, rubberiness and/or juiciness in fruit after cold storage. Effects of position along the shoot, fruit number and fruiting node leaf area on fruit quality were examined for one cultivar. FW, SSC and DMC were higher in fruit on distal zones of 2-year-old wood, but were lower in fruit from distal zones of 1-year-old wood. Greater fruit number per shoot before thinning decreased FW on 2-year-old wood. On 1-year-old wood, there was an interaction between fruiting node leaf area, position and fruit FW. These results will assist in devising management techniques, such as differential thinning and pruning, to reduce fruit quality variation.

Aging of wood under long-term storage in a salt environment

Aging of archeological wood in a salt environment was assessed in Hallstatt, Upper Austria, where Bronze Age wooden findings of the archeological salt mining site were compared with recent wood samples from the same site. Three species (Picea abies, Abies alba and Fagus sylvatica) were investigated. Recent samples covered all main geological units within the salt valley. FTIR spectroscopy was used to determine differences in wood chemistry. Principal component analysis was used to display the segregation of the data set according to the different factors and to give a measure of the strength of the effects. Results revealed that deacetylation processes took place at the wood material. The aging process affects wood chemistry significantly stronger than differences in earlywood and latewood. Together these two factors accounted for 80 % of data variability. As a third factor, the tree species segregated the data set. Geological differences in the sampling sites were not mirrored in the FTIR spectra.

Optimization of Head Space Sorptive Extraction to Determine Volatile Compounds from Oak Wood in Fortified Wines

Head space sorptive extraction (HSSE) has been evaluated for the analysis of volatile compounds from oak wood in wines. The extraction conditions have been optimized using a two-level factorial design. After optimization, the final extraction conditions were: PDMS stir bars (20 mm length × 0.5 mm film thickness), sample volume of 5 mL, extraction time 120 min, stirring speed 2000 rpm, and NaCl until saturation. The HSSE optimized method was further validated and showed high linearity (r2 > 0.9960), adequate detection and quantification limits and linear ranges for the analysis of these compounds in aged wines. Moreover, it provided good values of analytical parameters such as precision and recovery (3.49–11.22 % for intra-assay precision, 4.35–8.77 % for inter-assay precision, and 70.6–124 % for recovery). The method was finally applied to different types of fortified wines (Mistelle, Fino and Oloroso wine) from Condado de Huelva Denomination of Origin submitted to different periods of aging in oak wood.