人工林木材前景展望：2005—2030年

2005年,全球人工林只占森林总面积的7％,但其所贡献的林产品和服务的比例却高得多。1967年,联合国粮农组织（FAO）的国际研讨会使人工林潜在的重要性得到全球性的公认。虽然工业原木的持续供应是主要的推动力,人工林的社会和环境效益也受到了关沣。     

Stabilization of caseinate-covered oil droplets during acidification with high methoxyl pectin

Polysaccharides are widely used in the food industry to modify the stability of protein-based drinks. However, an in depth knowledge of the interactions occurring in the system is still lacking. In this study, the interactions between sodium caseinate and high methoxyl pectin under acidification conditions were studied nondestructively and without dilution using transmission diffusing wave spectroscopy. Oil-in-water emulsions were prepared with 10% soybean oil and 0.5% sodium caseinate. Various concentrations of pectin (ranging from 0 to 0.2%) were added, and the emulsions were acidified with glucono-delta-lactone. With acidification, a "sol-gel" transition occurred and emulsions containing pectin were more stable at lower pH than those without pectin. Furthermore, the sol-gel transition of the mixtures was more sudden for control emulsions without pectin. While in control samples the final solidlike emulsion after gelation tended to be more inhomogeneous and more dissimilar to the starting emulsion, emulsions with pectin in solution gelled later under acidification. With a sufficient amount of pectin, the emulsions showed no aggregation and the destabilization pH varied depending on the amount of pectin present in the emulsions. At intermediate pH values (pH > 5.5), the emulsions displayed a decrease in particle size, more pronounced in samples containing pectin. The results collected using light scattering in concentrated systems, 10% (v/v) in our case, suggested that pectin stabilizes the emulsion oil droplets forming a network of oil droplets loosely connected by strands of pectin.     

Modelling of nitrogen loads from the farming of yellowtail kingfish Seriola lalandi (Valenciennes, 1833)

Farming of yellowtail kingfish ( Seriola lalandi , Valenciennes, 1833) in the coastal waters of Australia is a relatively new aquaculture industry, and little is known about the magnitude of nutrient discharges from individual pens. In this work, we modelled the flow of nitrogen for each of two commercial pens in Fitzgerald Bay, upper Spencer Gulf, South Australia. The fish were fed commercial pellets with feed conversion ratios (FCRs) between 3.0 and 3.2 (dry weight feed/wet weight growth). These high values of FCR were reflected in the high nitrogen loads to the environment (176–195 kg N tonne⁻¹ growth) and a small retention of nitrogen in fish growth (14–16% of feed inputs). Considering an annual production of 2000 tonnes, total loads to the environment can reach 391 tonnes N year⁻¹. Eighty-two per cent of these loads are expected to be lost to the water column as dissolved wastes. The high nutrient loads and the importance of dissolved wastes compared with other aquaculture species, such as salmon and trout, reflect the distinctly higher metabolic rates of this pelagic predatory species. The nature of the wastes suggests low localized impacts at current production levels, but regional effects remain unknown.     

Decision making in urban forestry by using approval voting and multicriteria approval method (case study: Zvezdarska forest,Belgrade, Serbia)

This paper deals with a common urban forestry problem: selecting the most appropriate management policy for a forest situated within a city zone. In the presented case study, we analyzed this problem within the Zvezdarska forest in Belgrade, Serbia. The decision makers that took part in the decision making process represented the two main stakeholder groups – the public and the experts. The public group is divided into three different subgroups: local residents, tourists and environmentalists. The experts group is represented by local authorities and academic experts. The procedure implemented for evaluating and selecting the most desired management policy for the case study area combines approval voting and the multicriteria approval method, two social choice theory methods suitable for decision-making in forestry. The main reason for combining these techniques is to be sure that the selected policy will be accepted as the most desired option by both the public and the experts. The results and discussions with involved decision makers clearly show that the applied procedure possesses sufficient analyticity and full transparency in the decision-making process; hence it is applicable to problems in urban forest management as well as to natural resources in general.     

Deoxynivalenol, deoxynivalenol-3-glucoside, and enniatins: the major mycotoxins found in cereal-based products on the Czech market

Fusarium toxins, Alternaria toxins, and ergot alkaloids represent common groups of mycotoxins that can be found in cereals grown under temperate climatic conditions. Because most of them are chemically and thermally stable, these toxic fungal secondary metabolites might be transferred from grains into the final products. To get information on the commensurate contamination of various cereal-based products collected from the Czech retail market in 2010, the occurrence of "traditional" mycotoxins such as groups of A and B trichothecenes and zearalenone, less routinely determined Alternaria toxins (alternariol, alternariol monomethyl ether and altenuene), ergot alkaloids (ergosine, ergocryptine, ergocristine, and ergocornine) and "emerging" mycotoxins (enniatins A, A1, B, and B1 and beauvericin) were monitored. In a total 116 samples derived from white flour and mixed flour, breakfast cereals, snacks, and flour, only trichothecenes A and B and enniatins were found. Deoxynivalenol was detected in 75% of samples with concentrations ranging from 13 to 594 μg/kg, but its masked form, deoxynivalenol-3-β-d-glucoside, has an even higher incidence of 80% of samples, and concentrations ranging between 5 and 72 μg/kg were detected. Nivalenol was found only in three samples at levels of 30 μg/kg. For enniatins, all of the samples investigated were contaminated with at least one of four target enniatins. Enniatin A was detected in 97% of samples (concentration range of 20-2532 μg/kg) followed by enniatin B with an incidence in 91% of the samples (concentration range of 13-941 μg/kg) and enniatin B1 with an incidence of 80% in the samples tested (concentration range of 8-785 μg/kg). Enniatin A1 was found only in 44% of samples at levels ranging between 8 and 851 μg/kg.     

Study of the Chemical Changes and Evolution of Microbiota During Sourdoughlike Fermentation of Wheat Bran

Several studies have emphasized the possibility of enhancing nutritional properties of cereal by‐products through biotechnological processes. Bran fermentation positively affects the bioavailability of several functional compounds. Moreover, bran fermentation could increase water‐extractable arabinoxylans (WEAX), compounds with positive effects on glucose metabolism and prebiotic properties. This study was aimed at increasing the amount of bran bioactive compounds through a sourdoughlike fermentation process. Wheat bran fermentations were conducted through continuous propagation by back‐slopping of fermented bran (10% inoculum) until a stable microbiota was established, reaching high counts of lactic acid bacteria and yeasts (10⁹ and 10⁷ CFU/g, respectively). At each refreshment step, bacterial strains were isolated, clustered, molecularly analyzed by randomly amplified polymorphic DNA, and identified at the species level by 16S rRNA gene sequencing. Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus sakei, Lactobacillus plantarum, Pediococcus pentosaceus, and Pichia fermentans dominated the stable sourdough ecosystem. After fermentation, levels of soluble fiber increased (+30%), and WEAX and free ferulic acid were respectively fourfold and tenfold higher than in raw bran, results probably related to microbial xylan‐degrading activity, whereas phytic acid was completely degraded. These preliminary data suggest that fermented bran could be considered an interesting functional ingredient for nutritional enhancement.     

Collection,ex situ conservation and characterization of mangaba (Hancornia speciose Gomes) germplasm in coastal lowland of Northeastern Brazil

Genetic Resources and Crop Evolution - This study aimed to evaluate the Mangaba Genebank of Embrapa Tabuleiros Costeiros, Brazil, since its implementation in 2006 and characterize the accessions in...     

Immunoglobulins in normal porcine tracheobronchial secretions

Methods of collecting sputum and tracheobronchial washings are described.Proteins in normal porcine tracheobronchial secretions are studied by immunochemical qualitative and quantitative methods. Among the immunoglobulins, IgA, IgG and IgM are identified. Immunoelectrophoretic analysis of sputum shows albumin, transferrin and in the α-region 2 components not found in serum. The predominant immunoglobulin in tracheobronchial secretions is IgA, which accounted for about 85 % of the total immunoglobulin concentration in sputum and 61 % of the immunoglobulin concentration in tracheobronchial washings.     

Study of the effect of soy proteins on the acid-induced gelation of casein micelles

The objective of this research was to understand whether addition of soy protein to milk protein affects the properties of acid-induced casein gels. Different samples were prepared by suspending casein micelles pellets in milk serum containing soy proteins or whey proteins as well as mixtures of the two proteins. Glucono-delta-lactone was added, and the changes in apparent size (in diluted systems) as well as the viscoelastic properties of the mixtures were measured. Size exclusion chromatography was also carried out to characterize the soluble phase of the various mixtures before and after heating. Soy protein affected the gelation of the mixtures; however, not to the same extent as whey proteins, which dominated formation of the network in soy-whey-casein systems. It was concluded that, up to a critical ratio of soy/whey proteins, soy proteins can be incorporated in the mix without a significant change in structure of the casein gels.     

Addition of pectin and soy soluble polysaccharide affects the particle size distribution of casein suspensions prepared from acidified skim milk

Pectins are negatively charged polysaccharides employed as stabilizers in acidified milk dispersions, where caseins aggregate because of the low pH and serum separation needs to be prevented. The objective of this research was to study the effect of charge on the stabilizing functionality of the polysaccharide in acid milk drinks. Unstandardized pectins with various charges (as degree of esterification, DE) as well as soybean soluble polysaccharide (SSPS) were tested for their stabilizing behavior as a function of pH and concentration. Skim milk was acidified by glucono-delta-lactone and then homogenized in the presence of polysaccharide at different pH values (in the range from 4.2 to 3.0). Measurements of particle size distribution demonstrated that pectins with a DE of 71.4, 68.6, and 67.4 stabilized milk at pH > 4.0. Pectins with a lower DE (63.9%) needed a higher concentration (0.4%) at the same pH to show a monomodal distribution of particle sizes. Pectins with lower DE (<50%) did not stabilize the dispersions. Although this difference in behavior was attributed mainly to the pectin charge, the efficiency in stabilizing the casein dispersion decreased with decreasing pectin size. For example, the high methoxyl pectin (HMP) with 63.9 DE was smaller in size than the HMPs with a higher charge. Pectins showed a pH-dependent stabilization effect, as at pH < 4.0 the dispersions contained aggregates. When SSPS was used to stabilize acid milk, at pH < 4.0, it showed a better stabilization behavior than HMP. When SSPS and pectin were used in combination, the particle size distribution of the acid milk dispersion was pH-dependent, and results were similar to those for samples containing pectin alone. This suggested that in the mixture, pectin dominated the behavior over SSPS, even when an excess of SSPS was added to the dispersions before homogenization.