Deamidation of gluten proteins and peptides decreases the antibody affinity in gluten analysis assays

Wheat gluten is a widely used ingredient in the food industry due to its unique properties and relatively low price. Modification of wheat gluten makes it a versatile ingredient and, thus, increases its applicability in foods. Therefore, gluten proteins can be found in unexpected sources, and this makes the gluten-free diet challenging to follow. Deamidation is one way to modify protein structure. It increases solubility and surface activity of gluten improving its functionality, but consequently, also influencing the accuracy of quantification by immunoassays. In this study, the effect of deamidation on the antibody recognition with gluten analysis methods based on monoclonal R5, omega-gliadin or G12 antibodies was studied. Random deamidation decreased the intensities to 13–54% of the intensity obtained for the intact peptides. Deamidation representing the transglutaminase deamidation decreased the intensities to 4–8%. Deamidation of gluten proteins abolished the recognition by omega-gliadin and G12 antibodies and decreased the recognition of R5 by 600 times when analyzed by the sandwich method and 125 times by the competitive method. In conclusion, with all of the investigated gluten-specific antibodies, deamidation decreased the affinity of antibodies to gluten peptides and proteins, which needs to be considered when assays and regulations are developed for gluten-free products.     

Malt hydrolysates for gluten-free applications: Autolytic and proline endopeptidase assisted removal of prolamins from wheat,barley and rye

Cereal based products intended for gluten sensitive individuals, particularly to celiac disease patients, tend to have poor organoleptic qualities and they contain low levels of healthy whole grain compounds. Adding whole grain ingredients, such as malt hydrolysates, could compensate these defects provided that the ingredients are adequately free from toxic prolamin epitopes. Here we demonstrate that the level of toxic prolamin epitopes in the malt autolysates (wheat, barley, rye) were substantially lower than in the native malts but too high to allow “very low in gluten” labelling. To further eliminate the residual levels of toxic prolamin epitopes, a proline-specific endoprotease from Aspergillus niger was added to the malt autolysates. In the resulting malt hydrolysates (of wheat and rye but not barley), the prolamins were indeed greatly reduced and were below the very low gluten limit of 100 mg/kg. Malt hydrolysates with adequately low gluten levels may potentially be used as novel ingredients within gluten-free foods.     

Ice fishing reveals size structure but not abundance of Eurasian perch in small boreal lakes

Management of inland recreational fisheries would benefit from stock abundance and size structure data. Feasibly standardised angling methods such as ice fishing could produce representative catch-per-unit-effort (CPUE) information on the abundance of different-sized fish in small lakes. Here, we first used standard Nordic multimesh gillnets to obtain number-per-unit-effort (NPUE), biomass-per-unit-effort (BPUE) and size structure data on Eurasian perch (Perca fluviatilis) stocks in 11 small boreal lakes in summer. Second, the same lakes were ice-fished by voluntary anglers using a pre-defined, loosely standardised protocol to obtain angling-based NPUE, BPUE, and length frequency distributions. Effects of environmental variables such as water oxygen concentration and light penetration on angling catch rates were controlled statistically. Neither perch Nordic gillnet NPUE nor BPUE corresponded to ice-fishing CPUEs. However, the length distribution of the catch did not differ between methods. Our results imply that traditional ice fishing applying natural baits is relatively unselective for fish size and could produce valid length-based indicators for management purposes while angling CPUE was poorly related to Nordic gillnet CPUE.     

Estimating forest data for analyses of forest production and utilization possibilities at local level by means of multi-source National Forest Inventory

The sample plot data of National Forest Inventories (NFI) are widely used in the analysis of forest production and utilization possibilities to support national and regional forest policy. However, there is an increasing interest for similar impact and scenario analyses for strategic planning at the local level. As the fairly sparse network of field plots only provides calculations for large areas, satellite image data have been applied to produce forest information for smaller areas. The aim of this study was to test the feasibility of generating forest data for a Finnish forest analysis tool, the MELA system, by means of the Landsat satellite imagery and the NFI sample plot data. The study was part of the preparation of a local forestry programme, where a strategic scenario analysis for the forest area of two villages (ca 8000 ha) was carried out. Management units that approximate forest stands were delineated by image segmentation. Stand volume and other parameters for each forest segment were estimated from weighted means of the NFI sample plots, where the individual sample plot weights were estimated by the k nearest neighbour (kNN) method. Two different spectral features were tested: single pixel values and average pixel values within a segment. The estimated forest data were compared with the forest data based on independent stand-level field assessments in two subareas, a national park and an area of forest managed for timber production.In the national park, the estimated mean volume of the growing stock from both spectral feature sets (about 160 m³ ha⁻¹) was clearly lower than that obtained from stand-level field assessment (186 m³ ha⁻¹). Using average pixel values within a segment resulted in a higher proportion of pine and a lower proportion of spruce volume than using single pixel values. It also resulted in an estimated felling potential nearly 10% higher over the first 10-year period in the scenario analysis of the area dedicated to timber production. However, the maximum long-term sustainable removal was at the same level (about 30,000 m³ year⁻¹) for both feature sets over the simulated 30-year period. The resulting annual felling area in the first 10-year period was 12% lower when the segment averages were applied, but the difference subsequently levelled off. The kNN approach in estimating initial forest data for scenario analyses at the local level was found promising.     

Effects of varying thinning regimes on carbon uptake,total stem wood growth,and timber production in Norway spruce (<Emphasis Type="BoldItalic">Picea abies)</Emphasis> stands in southern Finland under the changing climate

• Introduction  

Based on previous studies, it is assumed that the growth of Norway spruce (Picea abies) in southern Finland (61°N) may decrease under the changing climate due to the increasing soil water deficit, without management.     

Dendroclimatological analysis of seeded and thinned Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) stands at the coniferous timberline

Radial growth was examined in two Scots pine stands that were seeded during the 1920s and 1930s due to reforestation and afforestation activity on the timberline of northern Finnish Lapland. Tree-rings of seeded pines were calibrated against the instrumental records of local weather and large-scale atmospheric patterns and further compared to pines of natural origin on the timberline. The studied stands were shown to contain common growth variability that differed from the variability of natural pines. Deviating growth of seeded pines was attributed to their only moderate growth dependence on mid-summer (July) temperatures and, likewise, their strong dependence on the autumn climate in the previous year, and linked to the different genetic origin of artificial stands due to southern seeds. Stands were thinned for different densities in 1985 and 1986. The growth response to thinning was markedly better than could be expected according to previous studies. We found that the positive growth reaction conceivably benefited from the ameliorated winter conditions, expressed as warmed (March) temperatures and the prolonged positive phase of the Arctic Oscillation (February). The results emphasize the determining influence of climatic fluctuations on reforestation and afforestation near the distributional limits of tree species.     

The effects of soil and air temperature on CO2 exchange and net biomass accumulation in Norway spruce, Scots pine and silver birch seedlings

Soil temperature is proposed to affect the photosynthetic rate and carbon allocation in boreal trees through sink limitation. The aim of this study was to investigate the effect of temperature on CO(2) exchange, biomass partitioning and ectomycorrhizal (ECM) fungi of boreal tree species. We measured carbon allocation, above- and below-ground CO(2) exchange and the species composition of associated ECM fungi in the rhizosphere of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies K.) and silver birch (Betula pendula Roth) seedlings grown in soil maintained at 7-12, 12-15 and 16-22 °C. We found increased root biomass and photosynthetic rate at higher soil temperatures, but simultaneously with photosynthesis rate, higher temperature generally increased soil respiration as well as shoot, and root and rhizosphere respiration. The net CO(2) exchange and seedling biomass did not increase significantly with increasing temperature due to a concomitant increase in carbon assimilation and respiration rates. The 2-month-long growth period in different soil temperatures did not alter the ECM fungi species composition and the below-ground carbon sink strength did not seem to be directly related to ECM biomass and species composition in any of the tree species. Ectomycorrhizal species composition and number of mycorrhiza did not explain the CO(2) exchange results at different temperatures.     

Near-infrared characteristics of forest humus are correlated with soil respiration and microbial biomass in burnt soil

Near-infrared spectroscopy and soil physicochemical determinations (pH_H2O, organic matter content, total C content, NH _inf4 ^sup+ , total N content, cation-exchange capacity, and base saturation) were used to characterize fire-or wood ash-treated humus samples. The spectroscopic and the soil physicochemical analysis data from the humus samples were used separately to explain observed variations in soil respiration and microbial biomass C by partial least-square regression. The first regression component obtained from the physicochemical and spectroscopic characterization explained 10–12% and 60–80% of the biological variation, respectively. This suggests that information on organic material collected from near-infrared spectra is very useful for explaining biological variations in forest humus.     

Treefall gaps of certified,conventionally managed and natural forests as regeneration sites for Neotropical timber trees in northern Honduras

Forest certification programmes promote sustainable management of the world's forests. Certification can be given to a forest management system that fulfils certain environmental, social and economic criteria.     

Durability of thermally modified sapwood and heartwood of Scots pine and Norway spruce in the modified double layer test

In the present study, durability of untreated and thermally modified sapwood and heartwood of Scots pine and Norway spruce was examined using a modified double layer test. Base layer samples were partly on contact with ground where exposure conditions were harder than that in a double layer test above the ground. The base layer on ground contact gave results already after one year of exposure in Finnish climate, but the top layer of a double layer test element simulated more the situation of decking exposure.

Significant differences in durability and moisture content (MC) between the wood materials were detected after six years of exposure in the field. Thermally modified pine heartwood performed very well in all layers of the test element and only minor signs of decay were found in some of the base samples. Both sapwood and heartwood of thermally modified spruce were suffering only slight amounts of decay while thermally modified pine sapwood was slightly or moderately decayed. Untreated sapwood samples of pine and spruce were severely decayed or reached failure rating after six years in the field. Untreated heartwood samples performed clearly better. The highest MCs were measured from untreated and thermally modified pine samples. Thermal modification increased significantly the durability and decreased the MC values of all wood materials.