Knotwood and bark extracts: strong antioxidants from waste materials

The antioxidant properties of hydrophilic extracts of knotwood of several industrially important tree species were evaluated by lipid-peroxidation inhibition and peroxyl-trapping capacity tests. The results were compared with the antioxidant properties of hydrophilic extracts of bark, and pure lignans and flavonoids isolated from knotwood extracts. The knot extracts from several tree species were stronger antioxidants than the bark extracts, which can, however, also be classified as strong antioxidants. In addition, the antioxidant properties of most of the knotwood extracts are stronger than the pure compounds. It is concluded that knotwood is a rich source of natural antioxidants.     

Recovery of bioactive compounds from Pinus pinaster wood by consecutive extraction stages

Pinus pinaster wood samples, obtained at different positions of three healthy trees, were subjected to two sequential extractions using an Accelerated Solvent Extraction instrument. The first extraction was carried out with hexane (to remove lipophilic extractives) and the second one with acetone/water (95:5 v/v) to recover bioactive phenolic compounds, the target compounds of this study. The extracted fractions were assayed for total yield and composition. The extracts contained a spectrum of phenolic compounds (simple phenolics, phenolic stilbenes, flavonoids and lignans) and non-phenolic components (juvabiones, resin and fatty acids, steryl esters and triglycerides). The fractionation effects achieved by consecutive extractions and the recovery of bioactive phenolics are discussed.     

Antioxidant activity of knotwood extractives and phenolic compounds of selected tree species

The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by gas chromatography combined with mass spectrometry. Most of the investigated wood species were rich in hydrophilic extractives (10-20% of the dry wood) with one or a few compounds dominating in each extract. All extracts had a high antioxidative potency and/or radical scavenging capacity as compared to the well-known antioxidants Trolox and butylated hydroxyanisole. The pure wood-derived lignans and taxifolin also had a high antioxidative potency and/or radical scavenging capacity. However, the antioxidant potency and/or radical scavenging capacity of several of the hydrophilic knotwood extracts were higher than that of the dominating compounds in pure form.     

The proximate architecture for decision‐making in fish

Evolution has since the very beginning resulted in organisms which can sort fitness‐related information from noise, evaluate it and respond to it. In animals, the architecture for proximate control of behaviour and physiology has been gradually evolving since before the Cambrian explosion of animal phyla. It integrates many different survival circuits, for example for danger, feeding and reproduction, and operates through reflexes, instincts, homeostatic drives and precursors to human emotions. Although teleost brains differ substantially from the much better understood brains of terrestrial vertebrates, their anatomy, physiology and neurochemistry all point towards a common and malleable architectural template with strong and flexible effects on fish behaviour and elements of personality. We describe the main components of this architecture and its role in fish behaviour from the perspectives of adaptation, evolutionary history and gene pools. Much research is needed, as several of the basic assumptions for architectural control of behaviour and physiology in teleosts are not thoroughly investigated. We think the architecture for behavioural control can be used to change ecosystem models from a bottom‐up perspective to also include behaviourally mediated trophic cascades and trait‐mediated indirect effects. We also discuss the utility of modelling based on proximate architectural control for fish welfare studies.     

Carbohydrate analysis of plant materials with uronic acid-containing polysaccharides–A comparison between different hydrolysis and subsequent chromatographic analytical techniques

Acid hydrolysis, acid methanolysis, and enzymatic hydrolysis were compared for depolymerization of five different plant materials containing uronic acids. The analyzed plant materials were oat spelt, wheat straw, spruce thermomechanical pulp, aspen stemwood, and totally chlorine-free (TCF) bleached hardwood kraft pulp. Furthermore, GC (using both HP-1 and HP-5 capillary columns and FID and MSD detectors), HPAEC-PAD, and HPAEC-Borate techniques were compared for subsequent analysis of the released monosaccharides. It was shown that acid methanolysis combined with GC analysis is a convenient method for obtaining the sugar unit composition and amount of non-crystalline polysaccharides in different plant materials. The methanolysis method was generally superior to the hydrolysis method for xylan- and uronic acid-containing samples. However, acid and enzymatic hydrolysis showed the highest recoveries for bleached chemical pulp samples. Acid hydrolysis is also required for crystalline polysaccharides, but the strong acid conditions evidently lead to degradation of labile sugars. The plant methanolysates were not suitable as such for analysis on an HPAEC-PAD system. For analysis of the total amount of sugar units, hence including cellulose, other non-crystalline hemicelluloses, and pectins, a combination of the methanolysis and hydrolysis methods is recommended.     

Kinetics of acid hydrolysis of water-soluble spruce O-acetyl galactoglucomannans

Water-soluble O-acetyl galactoglucomannan (GGM) is a softwood-derived polysaccharide, which can be extracted on an industrial scale from wood or mechanical pulping waters and now is available in kilogram scale for research and development of value-added products. To develop applications of GGM, information is needed on its stability in acidic conditions. The kinetics of acid hydrolysis of GGM was studied at temperatures up to 90 degrees C in the pH range of 1-3. Molar mass and molar mass distribution were determined using size exclusion chromatography with multiangle laser light scattering and refractive index detection. The molar mass of GGM decreased considerably with treatment time at temperatures above 70 degrees C and pH below 2. The molar mass distribution broadened with hydrolysis time. A first-order kinetic model was found to match the acid hydrolysis. The reaction rate constants at various pH values and temperatures were calculated on the basis of the first-order kinetic model. Furthermore, the activation energy, E, was obtained from the Arrhenius plot. The activation energy E was 150 kJ mol (-1) for acid hydrolysis of spruce GGM. The apparent rate constant during acid hydrolysis increased by a factor of 10 with a decrease in pH by 1 unit, regardless of temperature. In addition, gas chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were applied to study the released GGM monomers and oligomers.     

Probing structural periodicity (annual ring size) in Scots pine by NMR profiling

The water distribution along a direction normal to the annual rings of a water-saturated sapwood sample from Scots pine (9 mm of length) was determined using NMR one-dimensional imaging. The NMR profiles were obtained at a low-field NMR instrument using pulsed field gradients in Hahn echo experiments. Using a gradient pulse of 60 G/cm, a spatial resolution of 12 μm along the axis was obtained. A subsequent Fourier analysis of the signal intensity along the specified direction enabled the size distribution of the annual rings together with the relative amount of water within the rings to be estimated. The technique is a non-damaging way to determine the annual ring profile in wood, and can be further developed as a mobile technique for annual ring profiling of whole trees.     

New organizational forms within the aquaculture industry: The fish‐farming enterprise as a ‘virtual’ organization

Abstract

The international aquaculture industry is characterized by a global integration process with increasing competition across borders and continents. The rapid development of technology, the extended market rivalry due to new firm entries, and the elevation of quality standards in the international seafood market place a heavy strain on the strategy development process of aquaculture enterprises. In this article, we focus on the ties between strategic positioning in the market and the organizational configuration of the firm. The virtual organization is introduced as an organizational form for a dynamic fish‐farming enterprise. A virtual organization is characterized by flexible borders, emphasis on external cooperative relations and networks instead of ownership integration, and norm‐based relational contracts as focal governance mechanism. The results from an in‐depth, longitudinal study of a Norwegian fish farming enterprise are presented.     

Effect of altitude on the composition of suberin monomers in the outer bark of Scots pine (Pinus sylvestris L.)

The changes in the amount and composition of suberin monomers of Scots pine outer bark, which is grown natively in Turkey, was investigated as a function of growing altitude. Samples were taken from every 100 m to 1300 m which was the highest point of the sampling area. While the total amount of suberin monomers is varied within the range 17.56-47.20 mg/g, there was no correlation between total amount and altitude. Total amount of alkanols of suberin monomers decreased when the altitude increased. Alcohol 24:0 was seen as the dominant constituent and its amount decreased from 100 m to 1300 m. There was not a clear change in the total amount of alkanoic, dioic and hydroxy acids. Acid 1,18-hydroxy-18:1 and acid 1,18-dioic-18:1 were determined as the main compounds in all samples.