Influence of variety,date of harvest and storage time on factors connected with the crystallisation on canned scorzonera (Scorzonera hispanica)

In the period 1983–1986, research was carried out into the inulin content of scorzonera during ripening and storage. Since the inulin content is determining for the occurrence of crystallisation with canned scorzonera, the effects of the varieties, the time of harvest and storage of the scorzonera were investigated.The changing of the inulin content on the conversion into reducing sugars was checked; the effect of the dry matter and nitrate content were also defined.The aim was to define whether the determination of the inulin content was a useful parameter for the ripening of the scorzonera. On the whole, the different varieties showed remarkable difference where fructosanes+inulin, as well as pure inulin, were concerned.A significant decrease of the inulin content was obtained from the middle of November, by so far that it was below the limit above which crystallisation takes place.A two-month storage period of scorzonera harvested in early October also led to a very low inulin content, so that no problems could occur while canning. Storage conditions of the scorzonera seemed of importance too.The nitrate content of the different scorzonera varieties was low, although some variations were noted. The crops harvested in early December showed considerably lower contents when compared to those harvested in early October or mid-November.The inulin content as well as the content of reducing sugars are a useful parameter to determine the maturity of the scorzonera.This research was subsidized by the Instituut tot Aanmoediging van het Wetenschappelijk Onderzoek in Nijverheid en Landbouw (I.W.O.N.L.).     

Sustainable management, earthquake disturbances, and transient dynamics: modelling timber harvesting impacts in mixed-species forests

Context

There is strong interest in sustainable forest management systems that preserve characteristics of forests close to naturalness. Assessing the effectiveness of these systems is difficult because defining “natural” baselines from which impacts are estimated is challenging and because the influence of harvesting can have complex interactions with major natural disturbances.

Aims

We used SORTIE/NZ, an individual tree-based forest dynamics model, to understand how harvesting and earthquake disturbance affect the dynamics of a New Zealand podocarp–angiosperm forest.

Methods

Having parameterized SORTIE/NZ with extensive field data, we ran simulations for three natural dynamics scenarios (no disturbance and two earthquake scenarios) and then added podocarp harvesting scenario to each of these.

Results

Simulations suggest that this forest is experiencing transient dynamics, with a natural rise in the dominance of one species of slow-growing podocarp with and without earthquake. Harvesting podocarps strongly affected its increase in basal area.

Conclusion

Our results indicate that transient dynamics may occur in mixed podocarp forests and major disturbances may have complex interactions with management. Evaluating management impacts without accounting for these complex dynamics may be misleading. Models make predictions about transient trajectories that may help to evaluate these impacts.     

Fatty acid and tocopherol patterns of variation within the natural range of the shea tree (Vitellaria paradoxa)

The shea tree, Vitellaria paradoxa, is one of the most economically and culturally important indigenous tree species in the Sudano-Sahelian region. Its seeds contain a vegetable fat, internationally known as shea butter, which is widely used in edible, cosmetic and pharmaceutical sectors. Based on samples from 456 trees distributed in 17 locations across the species natural range from Senegal to Uganda, the fatty acid and tocopherol variation, and its relationship with geographic and climatic variables, was assessed in order to address the pattern and the origin of this variation across the natural range. Significant differences between Western and Eastern regions for oleic, stearic acid, saturated–unsaturated acid ratio and γ-tocopherol were identified that it is postulated maybe a result of genetic drift due to the evolutionary history of shea tree populations. Within regions the difference among stands was significant for most constituents; however the major part of the variation was observed among trees within stand (53–90 %). Relationships with climatic variables were not verified, weakening evidence for clinal variation hypotheses suggested by previous studies.     

Progressive Juvenile Glomerulonephropathy in 16 Related French Mastiff (Bordeaux) Dogs

Background: Familial juvenile glomerulonephropathy (JGN) is reported in several breeds of dogs. The mode of inheritance and spectrum of pathological lesions vary among breeds. A progressive JGN was detected in a pedigree of French Mastiff (FM) dogs. Objectives: To describe clinical, laboratory, and histopathologic findings in related FM dogs suffering from progressive JGN and to determine the mode of inheritance of this condition. Animals: Sixteen affected and 35 healthy related FM dogs Methods: FM dogs <24 months of age and diagnosed with chronic kidney disease with evidence of proteinuria entered the study. Clinical, laboratory, histopathologic findings, and pedigree data were recorded. Results: Clinical signs were typical of progressive glomerulopathy with resultant renal failure. Increased blood urea nitrogen, creatinine and total cholesterol concentrations, and proteinuria were found in all patients. Affected dogs had abnormal kidney structure on abdominal ultrasound examination. Histopathologic examination revealed extensive cystic glomerular atrophy, glomerular hypercellularity, and capillary wall thickening without immune complex deposition when tested with immunohistochemistry or immunofluorescence. Electron microscopy did not disclose specific primary glomerular lesions. Mean age at death was 20 months and mean length of survival after diagnosis was 6 months. Both males and females from healthy parents were affected. An autosomal recessive mode of transmission is suspected, but a more complex mode of inheritance cannot be excluded. Conclusions and Clinical Importance: Progressive familial JGN occurs in FM dogs. Characterization of the pathogenesis and mode of inheritance of this disease warrants additional study.     

Soil organic carbon–stock changes in Flemish grassland soils from 1990 to 2000

Total soil organic‐carbon (SOC) stocks for grassland soils in Flanders (N Belgium) were determined for the Kyoto Protocol reference year 1990 and 2000 in order to investigate whether these soils have been CO₂ sinks or sources during that period. The stocks were calculated by means of detailed SOC datasets, which were available at the community scale for the whole of Flanders. The total SOC stocks for Flemish grassland soils (1 m depth) were estimated at 38 Mt SOC in 1990 and 34 Mt SOC in 2000. The loss of SOC resulted from a decrease in the SOC content of grassland soils (71%) and could also partly (29%) be explained by a decline in grassland area. Significant decreases in %SOC for the 0–6 cm depth layer were found for the 1990s for the coarser‐textured soils with SOC losses ranging between –0.3% and –0.5% over the 10 y period. Specific management practices that disturb the SOC balance such as conversion to temporary grassland and a reduction of animal‐manure application are hypothesized to have contributed to the observed loss of SOC stocks. We furthermore conducted an analysis of uncertainty of the 1990 and 2000 grassland SOC–stocks calculation using Monte Carlo analysis. Probability‐distribution functions were determined for each of the inputs of the SOC‐stock calculation, enabling us to assess the uncertainty on the 1990 and 2000 SOC stocks. The frequency distributions of these simulated stocks both closely approached lognormal distributions, and their 95%‐confidence intervals ranged between 150% and 50% of the calculated mean SOC stock. The standard error on the measured decrease in SOC stocks in Flemish grassland soils during the 1990s was calculated to be 7–8 Tg SOC, which is equivalent to twice this decrease. This clearly shows that large‐scale changes in SOC stocks are uncertainty‐ridden, even when they are based on detailed datasets.     

Enrichment of anhydrous milk fat in polyunsaturated fatty acid residues from linseed and rapeseed oils through enzymatic interesterification

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. The aim was to obtain and characterize physicochemically fats enriched with unsaturated C 18 fatty acids (oleic, linoleic, and, especially, linolenic acids) from natural vegetable oils. Binary blends of AMF/LO 100/0, 90/10, 80/20, 70/30, and 60/40 (w/w) were interesterified. The change in triacylglycerol (TAG) profiles showed that quasi-equilibrium conditions were reached after 4-6 h of reaction. Free fatty acid contents <1%. The decrease in solid fat content and in dropping point temperature obtained with increasing content of LO and interesterification resulted in good plastic properties for the products originating from the blends 70/30 and 60/40. This was confirmed by textural measurements. Melting profiles determined by differential scanning calorimetry showed complete disappearance of low-melting TAGs from LO and the formation of intermediary species with a lower melting temperature. Oxidative stability of the interesterified products was diminished with increasing LO content, resulting in low oxidation induction times. A ternary blend composed of AMF/RO/LO 70/20/10 gave satisfactory rheological and oxidative properties, fulfilling the requirements for a marketable spread and, moreover, offering increased potential health benefits due to the enriched content in polyunsaturated fatty acid residues.     

New perspectives on aquarium fish trade

ABSTRACT:   Since the 1990s, the international market for importing aquarium fish is suspicious of stock coming from South-East Asia. Fish catches are still executed with cyanide-based toxic products. In the present paper, the potential of the French Polynesian Islands to develop a marine aquarium fish business with a new approach is explored. Coral reef fish are captured at the larval stage with crest nets, then larvae are reared in aquaria before being put on the world ornamental fish market. This approach offers several advantages: (i) larvae are captured with a passive system placed on the reef crest (crest net) that does not destroy the environment and limits the stress on collected larvae; (ii) larvae are then put into farmed basins that allow them to be controlled sanitarily; and (iii) larvae are weaned at the farm and fed rapidly with artificial food. This method increases survival rates as it eliminates the food acclimatization problem of fish captured at adult stage (main cause of fish mortality in aquaria). Overall, reared larvae will constitute a new product in terms of species, sizes and quality of ornamental fish on the aquarium market.     

The effect of mixing organic biological waste materials and high-N crop residues on the short-time N2O emission from horticultural soil in model experiments

Manipulating the N release from high-N crop residues by simultaneous mixing of these residues with organic biological waste (OBW) materials seems to be a possible method to reduce NO₃^– leaching. The aim of this study was to examine whether the incorporation of OBW materials together with a high-N crop residue (celery) had also an effect on N₂O emission from horticultural soil under short-term and optimised laboratory conditions. A sandy loam soil and celery residues were mixed with different OBW materials and brought into PVC tubes at 80% water-filled pore space and 15°C. Every 2.5 h, a gas sample was taken and analysed by gas chromatography for its N₂O concentration. The soil amended with only celery residues had a cumulative N₂O emission of 9.6 mg N kg^–1 soil in 50 h. When the celery residues were mixed with an OBW material, the N₂O emission was each time lower than the emission from the celery-only treatment (between 3.8 and 5.9 mg N kg^–1 soil during maximum 77 h), except with paper sludge (17.2 mg N kg^–1 soil in 100 h). The higher N₂O emission from the paper sludge treatment was probably due to its unusually low C:N ratio. Straw, green waste compost 1 (GWC1) and 2 (GWC2), saw dust, and tannic acid reduced the N₂O emission of the celery treatment by 40 to 60%. Although the N₂O reduction potential can be expected to be lower and with differing dynamics under field conditions, this study indicates that apart from reducing NO₃^– leaching, OBW application may at the same time reduce N₂O emissions after incorporation of high-N crop residues.