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Amino sugars are key compounds of microbial cell walls, which have been widely used as biomarker of microbial residues to investigate soil microbial communities and organic residue cycling processes. However, the formation dynamics of amino sugar is not well understood. In this study, two agricultural Luvisols under distinct tillage managements were amended with uniformly 13 C-labeled wheat residues of different quality (grain, leaf and root). The isotopic composition of individual amino sugars and CO 2 emission were measured over a 21-day incubation period using liquid chromatography–isotope ratio mass spectrometry (LC–IRMS) and trace gas IRMS. Results showed that, the amount of residue derived amino sugars increased exponentially and reached a maximum within days after residue addition. Glucosamine and galactosamine followed different formation kinetics. The maxima of residue derived amino sugars formation ranged from 14 nmol g −1 dry soil for galactosamine (0.8% of the original concentration) to 319 nmol g −1 dry soil for glucosamine (11% of the original concentration). Mean production times of residue derived amino sugars ranged from 2.1 to 9.3 days for glucosamine and galactosamine, respectively. In general, larger amounts of amino sugars were formed at a higher rate with increasing plant residue quality. The microbial community of the no-till soil was better adapted to assimilate low quality plant residues (i.e. leaf and root). All together, the formation dynamics of microbial cell wall components was component-specific and determined by residue quality and soil microbial community.

Water shortages in many rice-growing regions, combined with growing global imperatives to increase food production, are driving research into increased water use efficiency and modified agricultural practices in rice-based cropping systems. Well-tested cropping systems models that capture interactions between soil water and nutrient dynamics, crop growth, climate and management can assist in the evaluation of new agricultural practices. The APSIM model was designed to simulate diverse crop sequences, residue/tillage practices and specification of field management options. It was previously unable to simulate processes associated with the long-term flooded or saturated soil conditions encountered in rice-based systems, due to its heritage in dryland cropping applications. To address this shortcoming, the rice crop components of the ORYZA2000 rice model were incorporated and modifications were made to the APSIM soil water and nutrient modules to include descriptions of soil carbon and nitrogen dynamics under anaerobic conditions. We established a process for simulating the two-way transition between anaerobic and aerobic soil conditions occurring in crop sequences of flooded rice and other non-flooded crops, pastures and fallows. These transitions are dynamically simulated and driven by modelled hydraulic variables (soil water and floodwater depth). Descriptions of floodwater biological and chemical processes were also added. Our assumptions included a simplified approach to modelling O 2 transport processes in saturated soils. The improved APSIM model was tested against diverse, replicated experimental datasets for rice-based cropping systems, representing a spectrum of geographical locations (Australia, Indonesia and Philippines), soil types, management practices, crop species, varieties and sequences. The model performed equally well in simulating rice grain yield during multi-season crop sequences as the original validation testing reported for the stand-alone ORYZA2000 model simulating single crops ( n = 121, R 2 = 0.81 with low bias (slope, α = 1.02, intercept, β = −323 kg ha −1 ), RMSE = 1061 kg ha −1 (cf. SD of measured data = 2160 kg ha −1 )). This suggests robustness in APSIM's simulation of the rice-growing environment and provides evidence on the usefulness of our modifications and practicality of our assumptions. Aspects of particular strength were identified (crop rotations; response to applied fertilizers; the performance of bare fallows), together with areas for further development work (simulation of retained crop stubble during fallows, greenhouse gas emissions). APSIM is now suitable to investigate production responses of potential agronomic and management changes in rice-based cropping systems, particularly in response to future imperatives linked to resource availability, climate change, and food security. Further testing is required to evaluate the impact of our simplified assumptions on the model's simulation of greenhouse gas emissions in rice-based cropping systems.

The spatial distribution pattern of silicon in the leaves of three species of Saccharum has been demonstrated by means of laser induced breakdown spectroscopy (LIBS). The in-situ point detection capability of LIBS was used to determine different elements in leaf samples. The concentrations of silicon and other elements in different parts of the leaves were estimated by measuring the intensities of their corresponding atomic lines. Silicon, deposited in the form of phytoliths, was also isolated by using the dry ash technique. LIBS observations showed that in all three Saccharum species, the concentration of silicon was highest in the midrib followed by that found in margin and vein areas. The concentration of silicon in S. officinarum is higher in comparison to S. spontaneum and S. bengalense. Furthermore, the concentration of silicon at the upper surface of the leaf was larger than at the lower surface. The LIBS spectra of Saccharum species also show the presence of spectral lines of Na, Mg, Ca, Fe, and K.

13 pages; International audience; Microbial communities are of major importance in the decomposition of soil organic matter. However, the identities and dynamics of the populations involved are still poorly documented. We investigated, in an 11-month field experiment, how the initial biochemical quality of crop residues could lead to specific decomposition patterns, linking biochemical changes undergone by the crop residues to the respiration, biomass, and genetic structure of the soil microbial communities. Wheat, alfalfa, and rape residues were incorporated into the 0-15 cm layer of the soil of field plots by tilling. Biochemical changes in the residues occurring during degradation were assessed by near-infrared spectroscopy. Qualitative modifications in the genetic structure of the bacterial communities were determined by bacterial-automated ribosomal intergenic spacer analysis. Bacterial diversity in the three crop residues at early and late stages of decomposition process was further analyzed from a molecular inventory of the 16S rDNA. The decomposition of plant residues in croplands was shown to involve specific biochemical characteristics and microbial community dynamics which were clearly related to the quality of the organic inputs. Decay stage and seasonal shifts occurred by replacement of copiotrophic bacterial groups such as proteobacteria successful on younger residues with those successful on more extensively decayed material such as Actinobacteria. However, relative abundance of proteobacteria depended greatly on the composition of the residues, with a gradient observed from alfalfa to wheat, suggesting that this bacterial group may represent a good indicator of crop residues degradability and modifications during the decomposition process.

A post-column fluorigenic reaction with benzamidine coupled to liquid chromatographic separation was used for the determination of reducing carbohydrates in three complex biological samples. This method allows the simultaneous determination of the different reducing sugars, which represents an improvement over batch enzymatic tests where in most instances only single monosaccharides can be determined. This selective liquid chromatographic method has a broad linear range. The method was validated by simultaneous analyses with a specific enzymatic test for glucose. Results are presented for the determination of glucose in human serum and mustard plants and glucose and fructose in white wines.

Objectives: Workers in many industries are exposed to endotoxins, which may cause adverse health effects. In exposure assessment, information about exposure variability is essential. However, variability in exposure has rarely been investigated for biological agents and more specifically for endotoxin. Therefore, variance components and determinants of exposure were studied in a large database with >2000 endotoxin measurements. Methods: Data from 10 individual studies were combined to create a database with 2010 personal inhalable dust and endotoxin measurements, of which 1650 were repeated measurements. Exposure groups were defined based on job codes. Between- and within-worker variance components were estimated for different grouping strategies, and determinants of exposure were studied using mixed effects models. Results: Inhalable dust and endotoxin exposure levels are summarized for 46 industries and 4 broadly defined sectors. The between-worker variability exceeded the within-worker variability overall and within sectors and subsectors, and variance components were larger for endotoxin than for dust. Between-worker variability also exceeded within-worker variability in nearly half of the exposure groups based upon industries or job code within industries for endotoxin exposure and in 10% of the groups for dust exposure. Among other things, dustiness of the process, contact with animals, bulk production, presence of plant material or a cyclic process appeared as determinants of exposure, which largely explained the between-worker variability. Conclusions: Exposure groups were much less homogeneous for endotoxin exposure than for dust exposure. This is distinctly different than for chemical exposure. Large variability in measured exposure levels is inherent to endotoxin exposure, which is caused in part by determinants that influence growth of microorganisms. These findings have major consequences for the design of future occupational intervention and epidemiological studies. The measurement effort needs to be greater than exposure assessment for chemical agents which demonstrate lower exposure variability, especially when evaluating endotoxin exposure for compliance testing. The established determinants of exposure give direction for potential exposure control, although more information about determinants of day-to-day variability in exposure is still needed to be able to effectively control endotoxin exposure. © The Author 2008. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

In this study the investigation of the aroma compounds of dried fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e. E. officinalis Dode) (Rutaceae family) was carried out to identify the odorous target components responsible for the characteristic aroma of these valuable natural products. To avoid the traditional and more time-consuming hydrodistillation, the analyses were carried out by means of headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The SPME headspace volatiles were collected using a divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber. The extraction conditions were optimized using a response surface experimental design to analyze the effect of three factors: extraction temperature, equilibrium time and extraction time. The best response was obtained when the extraction temperature was around 80 degrees C, equilibrium time near 25 min and extraction time close to 18 min. Analyses were performed by GC-MS with a 5% diphenyl-95% dimethyl polysiloxane (30 m x 0.25 mm I.D., film thickness 0.25 microm) capillary column using He as the carrier gas and a programmed temperature run. The main components of the HS-SPME samples of E. rutaecarpa (concentration >3.0%) were limonene (33.79%), beta-elemene (10.78%), linalool (8.15%), myrcene (5.83%), valencene (4.73%), beta-caryophyllene (4.62%), linalyl acetate (4.13%) and alpha-terpineol (3.99%). As for E. officinalis, the major compounds were myrcene (32.79%), limonene (18.36%), beta-caryophyllene (9.92%), trans-beta-ocimene (6.04%), linalool (5.88%), beta-elemene (7.85%) and valencene (4.62%).

This report summarizes the major features and outcome of the VTT research program "Tailored Technologies for Future Foods" (TTFF), conducted in 2001-2004. The program focused on exploiting of biosciences for specific processing and tailored product quality attributes: sensory quality, health effects and safety of food. It also aimed at understanding consumer food choice and the demands for future foods. The program was organised in research teams working on enzymatic modification of food materials, seed factory, microbial viability technology, encapsulation, structure engineering, physiological functionality and consumers and sensory quality. The total volume of the TTFF Program was 16.2 million EUR. The wide collaboration network covered 18 Finnish university and institute laboratories, and 37 institutions outside Finland. 59 companies and 10 development associations participated in the projects of the program. The research was reported in 185 international scientific publications including reviews and book chapters, and 48 articles in Finnish and 7 articles in trade magazines were published. 8 PhD theses have already been published, 2 more will be defended in 2005 and 3 more in 2006. The total number of theses published during the programme was 24. The number of patents or patent applications was 4. The report summarises major findings in the seven research teams, and gives 16 result cases. The research on cereal technology included enzymatic tailoring of rye, oat and high-fibre wheat bread baking, process-induced increase of rye bioactivity and design of cereal flavour. Enzymatic structure engineering concepts included search for novel cross-linking enzymes, and their use in proteinaceous food materials. Starch-based microcapsulation aimed at controlling stability of bioactive components. Enzymatic extraction of berry juice and especially phenolic compounds was developed, and berry phenolics were studied as selective inhibitors of the growth of intestinal pathogens. Methods for assessment of digestibility and gut bioconversions in vitro were developed. New technology was developed to produce plant-derived compounds in cell cultures, and also to increase and assess viability of probiotic bacteria. Germination was used as a tool to modify seed structure and composition for novel food applications. Consumer perceptions of functional foods was studied as well as perception of troublesome eating among the elderly.

This report summarizes the major features and outcome of the VTT research program "Tailored Technologies for Future Foods" (TTFF), conducted in 2001-2004. The program focused on exploiting of biosciences for specific processing and tailored product quality attributes: sensory quality, health effects and safety of food. It also aimed at understanding consumer food choice and the demands for future foods. The program was organised in research teams working on enzymatic modification of food materials, seed factory, microbial viability technology, encapsulation, structure engineering, physiological functionality and consumers and sensory quality. The total volume of the TTFF Program was 16.2 million EUR. The wide collaboration network covered 18 Finnish university and institute laboratories, and 37 institutions outside Finland. 59 companies and 10 development associations participated in the projects of the program. The research was reported in 185 international scientific publications including reviews and book chapters, and 48 articles in Finnish and 7 articles in trade magazines were published. 8 PhD theses have already been published, 2 more will be defended in 2005 and 3 more in 2006. The total number of theses published during the programme was 24. The number of patents or patent applications was 4. The report summarises major findings in the seven research teams, and gives 16 result cases. The research on cereal technology included enzymatic tailoring of rye, oat and high-fibre wheat bread baking, process-induced increase of rye bioactivity and design of cereal flavour. Enzymatic structure engineering concepts included search for novel cross-linking enzymes, and their use in proteinaceous food materials. Starch-based microcapsulation aimed at controlling stability of bioactive components. Enzymatic extraction of berry juice and especially phenolic compounds was developed, and berry phenolics were studied as selective inhibitors of the growth of intestinal pathogens. Methods for assessment of digestibility and gut bioconversions in vitro were developed. New technology was developed to produce plant-derived compounds in cell cultures, and also to increase and assess viability of probiotic bacteria. Germination was used as a tool to modify seed structure and composition for novel food applications. Consumer perceptions of functional foods was studied as well as perception of troublesome eating among the elderly.

Glycyrrhizin is one of the main bioactive components in liquorice (Glycyrrhiza uralensis Fisch) which has recently been found to be highly active in inhibiting replication of the severe acute respiratory syndrome (SARS)-associated virus. The separation and purification of glycyrrhizin from a methanol-water (70:30 (v/v)) extract of liquorice roots was achieved using high-speed counter-current chromatography. The separation was performed at a preparative scale in a one-step separation with a two-phase solvent system composed of ethyl acetate-methanol-water (5:2:5 (v/v)). The lower phase was used as the mobile phase in the head-to-tail elution mode. The present method yielded 42.2 mg glycyrrhizin at 96.8% purity from 130 mg of the crude exact with 95.2% recovery as determined by HPLC analysis.

Microwave closed-system wet digestion procedures for plant samples were examined. Each procedure was tested with samples of tobacco and cabbage, and included digestion by the use of different acids composition, almost complete evaporation of the digest, and then dissolution of the residue in 1% nitric acid. Three microwave digestion programs that varied power, duration, and temperature were used. Closed-vessel reactions followed open-vessel reaction-delay time. Using flame atomic absorption spectrometry on the digests, four or five elements were determined to evaluate effectiveness, precision and accuracy of analytes extraction into solution. After a preliminary study of tobacco digests, the four most effective procedures were chosen, and detailed investigations were carried out on both tobacco and cabbage reference materials. Although all four of the final procedures were accurate, the most precise procedure, with the lowest errors of determination, was using reverse ‘aqua regia’ for tobacco and ‘aqua re...

The application of immunoaffinity chromatography for the purification of Taxus plant and cell extracts prior to the HPLC analysis is described. Polyclonal antibodies raised against 10-deacetylbaccatin III (10-DAB III), paclitaxel's main precursor in plant, were characterised by enzymed-linked immunosorbent assay. Immunoglobulins from selected antisera were immobilised on CNBr-activated Sepharose 4B. The immunoaffinity column was used for the purification of plant and plant cell culture extracts prior to their analysis by HPLC. Immunoaffinity chromatography enabled the selective concentration of taxoids and enhanced sample clean-up. (C) 2002 Elsevier Science B.V. All rights reserved.

A liquid chromatographic (LC) method for the separation of both anthraquinone glycosides and aglycones in extracts of Rubia tinctorum was improved. For on-line MS detection atmospheric pressure chemical ionisation as well as electrospray ionisation (ESI) were used. The glycosides were ionised in both positive and negative ionisation (NI) mode, the aglycones only in the NI mode. With ESI ammonia was added to the eluent post-column to deprotonate the compounds. The efficiency of mass detection of the hydroxyanthraquinone aglycones was found to depend on the pK(a) value of the component. LC-diode-array detection and LC-MS provide useful complementary information for the identification of anthraquinones in plant extracts, which was proven with the identification of munjistin and pseudopurpurin. (C) 2002 Elsevier Science B.V. All rights reserved.

Rapid analytical methods for the determination of endosulfan isomers and endosulfan-sulfate in air and plant samples were developed. The insecticides were trapped from air using a column containing Florisil and extracted with a low volume of ethyl acetate, assisted by sonication. Pesticide residues were determined by gas chromatography with electron-capture detection using a nonpolar capillary column. Residue identities were confirmed by gas chromatography coupled with mass spectrometry. Recoveries of these compounds from air samples were always higher than 78% with an RSD lower than 11% and the detection limits obtained were at least 0.3 ng/l air. Leaf samples were homogenised with ethyl acetate and extracts cleaned-up on an aluminium oxide column. Pesticides were eluted with a hexane-ethyl acetate (8020, v/v) mixture. Recoveries obtained from plant samples were higher than 78% with an RSD lower than 14% and detection limits in leaves were 0.02 μg/g for each pesticide. These methods were applied to study the volatilisation of endosulfan from tomato leaves under laboratory conditions. A volatilisation rate near 1% of the initial amount of endosulfan per hour was obtained during the first 24 h at room temperature. © 2002 Elsevier Science B.V. All rights reserved.

The major phenolic diterpenes responsible for the antioxidant properties of rosemary extracts, namely carnosol and carnosic acid, were separated by capillary zone electrophoresis (CZE) using a 56 cm long uncoated fused-silica capillary and a 50 mM disodium tetraborate buffer of pH 10.1. The effect of the buffer type, pH and concentration, and the capillary length on the separation, was studied. Carnosol and carnosic acid were identified in the electrophoregrams of rosemary extracts through their migration times and UV spectra obtained by CZE analysis of pure compounds isolated from a rosemary extract by HPLC fractionation. The CZE method had good reproducibility (relative standard deviation less than 5%) and was applied to compare the contents of carnosol and carnosic acid in solid and oil-dispersed commercial extracts of rosemary and in rosemary leaves. The separation of carnosol and carnosic acid was accomplished in less than 11 min. © 2002 Elsevier Science B.V. All rights reserved.

En: Journal of chromatography A, ISSN 0021-9673 2001. n. 919 : 305-311 p. A simple HPLC method for vitamin E (a-tocopherol) measurement in the leaves of Rosmarinus officinalis has been developed and validated. It has enabled new data for a-tocopherol content to be established. The leaves, recently harvested, were dried in a microwave oven and crushed; then, a-tocopherol was directly extracted from portions of ground material with acetone, by probe sonication. After centrifugation the acetonic extract was analysed by HPLC with ergocalciferol (vitamin D ) added as internal standard and a gradient elution with a Nucleosil C column at 358C.Validation parameters of 2 18 the method can be considered adequate. For standards: linearity is r50.999, recovery is 10062%, intra-assay precision has RSD563% and inter-assay precision has RSD566%. For samples: linearity is r50.99, recovery: 9367%, intra-assay precision has RSD564% and inter-assay precision has RSD567%.

The application of osmotic dehydration as a pre-processing technique in food processing has not been fully utilised because of the lack of appropriate models that could be used for designing processing parameters and equipment. This study aimed to contribute to these needs by developing methods that describe the mass transfer behaviour of plant materials treated in osmotic solutions. Macroscopic and microscopic approaches were employed to describe the changes that occur in the tissues during the process. An in-depth study of apple tissues led to a method of classification that describes the rate of dehydration of various plant materials. This method took into account the initial states of the material and the various mass transfer resistances from the solution and the material itself. These behaviours were also verified with microscopy and image analysis. The measurements of the volumes of the cells are facilitated by the development of an image analysis program that automatically detects the cell's edges and measures the volume in three-dimension.

Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Vlswa Vidyalaya, Kalyani, West Bengal Manuscript received 17 December 1980, revised 17 August 1981, accepted 10 December 1981 A laboratory incubation study was undertaken to compare the carbon, nitrogen and sulphur mineralisation in a soil from three decomposing plant materials, namely, dhaincha (\(Sesbania\) \(aculeata\)), cowpea (\(Vigna\) \(sinenns\)) and waler-hyacinth (\(Eichorna\) \(crasspipes\)) of varying C/N, C/S and N/S ratios applied at five different levels. Both carbon and nitrogen mineralisation from three different plant materials followed the order : dhaincha≥cowpea≥water-hyaeinth. The extent of carbon mineralisation was found to be a reflection of the organic carbon content of tbe added organic matter. C/N ratio of the added plant material predominantly controls nitrogen mineralisation in soil. While sulphur mineralisation was found not only to depend on the sulphur content of the added plant material but also to their composition in relation to organic carbon and total nitrogen. &nbsp

The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, while beta-phellandrene (39-45%) was the main component in both the leaf and the root oil. Other components in the leaf oil were beta-myrcene (17%), sabinene (6.2%), Z-beta-ocimene (5.4%) and benzene acetaldehyde (4.1%). In the roots we found Z-beta-ocimene (16.9%) and alpha-pinene (4.6%) as other major components. These principle constituents of both essential oils were also present in the dichloromethane extracts of the fresh and dried leaves and the roots, although in much smaller percentages. Comparing hydrodistillation of fresh plant material with a dichloromethane extract, the latter yielded a considerably lower amount of constituents. In addition, air drying and freeze drying resulted in a significant loss of volatile constituents as compared to fresh material (dichloromethane extract). (C) 2002 Elsevier Science B.V. All rights reserved.