Size, shape and surface morphology of starch granules from Norway spruce needles revealed by transmission electron microscopy and atomic force microscopy: effects of elevated CO(2) concentration.

We compared the effects of ambient (350 ppm) and elevated CO(2) concentration (700 ppm) on the size and shape of starch granules in Norway spruce (Picea abies (L.) Karst.) needles during one growing season. Starch granules were isolated from needles by alkaline digestion and analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Measurements made with a particle size analyzer indicated that starch granules ranged between 0.5 and 10 microm. Granule size and shape varied according to needle developmental stage and CO(2) concentration. Generally, elevated CO(2) concentration increased the size of the starch granules. Fine surface structures (< 10 nm in size) studied by AFM were characterized by the presence of protrusions, furrows and pores.

Complex analytical approach to characterization of the influence of carbon dioxide concentration on carbohydrate composition in Norway spruce needles.

Water-soluble non-structural carbohydrates (NSC) in the needles of Norway spruce Picea abies [L.] Karst have been studied by using a combination of several separation techniques, having various detectors, with mass spectrometry. The intent was to find a suitable methodology that enables the characterization and determination of NSC, covering a wide range of molar masses, and being suitable to assess how NCS are influenced by both external conditions, e.g. different carbon dioxide (CO(2)) concentrations, light intensity, and by internal conditions such as the needle age. The techniques were liquid-liquid extraction, high performance liquid chromatography (HPLC), size exclusion chromatography (SEC), asymmetrical flow field-flow fractionation (AsFlFFF), electrospray ionization mass spectrometry (ESI-MS), and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). NSC were extracted by a methanol/chloroform/water mixture into the water-rich phase. Application of AsFlFFF and SEC, using refractive index (RI) and multi-angle light scattering (MALS) detectors to the water-rich extracts resulted in three or four main fractions covering molar masses from 10(3) to 10(6)g/mol. Individual fractions collected from SEC were directly subjected to both MALDI and ESI-MS analysis in order to identify NSC. MALDI mass spectra confirmed the presence of hexose oligomers in individual fractions while ESI-MS was used for evaluation of low mass NSC. HPLC-RI was used for quantification of NSC and predominant carbohydrates were found to be fructose, glucose, and sucrose. The changes in their content during seasonal course were studied in detail. HPLC coupled to ESI-MS enabled the identification of low concentration NSC like raffinose that occurred in the needles of autumn samplings. An influence of the increased CO(2) concentration on sucrose and glucose accumulation was observed and it was found that the light intensity as well as the needle age has significant influence on the sucrose content.

Determination of carbohydrates in juices by capillary electrophoresis, high-performance liquid chromatography, and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry.

The objective of this work was to develop a sample preparation procedure for determination of the carbohydrate profiles in commercial juice samples by three principally different analytical methods: capillary electrophoresis (CE) with indirect detection, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The preparation and purification of juice samples prior to analysis is described. The method using Carrez reagents was found to be an efficient preparation tool for all three methods. The addition of Carrez reagents to the samples for mass analysis improved the quality of the mass spectra of oligosaccharides. The amounts of glucose, fructose, and sucrose as major carbohydrates in fruit juices measured by CE using a simple instrument are in good agreement with the HPLC values and the data declared by the producers of the juices. The results from both methods are critically evaluated and their impact for studies of authenticity is discussed. The decrease of sucrose amount during the storage of samples was explained by acid hydrolysis of this disaccharide.