Composition Of Soluble Carbohydrates Research Articles

Effect of Proofing on the Rheology and Moisture Distribution of Corn Starch-Hydroxypropylmethylcellulose Gluten-Free Dough

Dough rheology, mainly enabled by gluten in the traditional dough, determines the end-products' quality, particularly by affecting gas production and retention capacities during proofing. Gluten-free dough has quite different rheological performance compared with gluten-containing dough. To deepen the understanding of gluten-free dough, variations of rheology and moisture distribution of corn starch-hydroxypropylmethylcellulose (CS-HPMC) gluten-free dough in the process of proofing were studied. Significant differences were found in terms of soluble carbohydrate composition, moisture distribution, and rheology. Arabinose, glucose, fructose, and mannose were the main composition of soluble carbohydrates in CS-HPMC dough, out of which glucose was preferentially utilized during proofing. Non-freezable water content and third relaxation time decreased from 44.24% and 2171.12 ms to 41.39% and 766.4 ms, respectively, whereas the amplitudes of T23 increased from 0.03% to 0.19%, indicating reduced bounded water proportion and improved water mobility with proofing time. Frequency dependence and the maximum creep compliance increased, whereas zero shear viscosity reduced, suggesting decreased molecular interactions and flowability, but improved dough rigidity. In conclusion, the reduced soluble carbohydrates and improved water mobility decreased molecular entanglements and hydrogen bonding. Furthermore, yeast growth restricted a large amount of water, resulting in declined flowability and increased rigidity.

The comparison of polymorphism among Avena species revealed by retrotransposon-based DNA markers and soluble carbohydrates in seeds

Here, we compared the polymorphism among 13 Avena species revealed by the iPBS markers and soluble carbohydrate profiles in seeds. The application of seven iPBS markers generated 83 bands, out of which 20.5% were polymorphic. No species-specific bands were scored. Shannon’s information index (I) and expected heterozygosity (He) revealed low genetic diversity, with the highest values observed for A. nuda (I = 0.099; He = 0.068). UPGMA clustering of studied Avena accessions and PCoA results showed that the polyploidy level is the main grouping criterion. High-resolution gas chromatography revealed that the studied Avena accessions share the same composition of soluble carbohydrates, but significant differences in the content of total (5.30–22.38 mg g−1 of dry weight) and particular sugars among studied samples were observed. Sucrose appeared as the most abundant sugar (mean 61.52% of total soluble carbohydrates), followed by raffinose family oligosaccharides (31.23%), myo-inositol and its galactosides (6.16%), and monosaccharides (1.09%). The pattern of interspecific variation in soluble carbohydrates, showed by PCA, was convergent to that revealed by iPBS markers. Thus, both methods appeared as a source of valuable data useful in the characterization of Avena resources or in the discussion on the evolution of this genus.

Soluble Carbohydrates in Several Transylvanian Potato Cultivars

This paper is the first to report the soluble carbohydrate content at harvest for eight Transylvanian potato cultivars: Christian, Cumidava, Kronstadt, Riviera, Roclas, Rustic, Tampa and Zamolxis. The aim of this study is to explore the soluble carbohydrate composition of the above-mentioned cultivars, since such quantitative information is important for breeding programs, consumers and processing units. High performance liquid chromatography was used for analysis, separations being achieved using a Prominence Shimadzu system with a refractive index detector, under isocratic conditions with a mobile phase consisting of acetonitrile: water (80:20%) delivered at 1 mL/min; baseline separations of the target analytes were accomplished with an EC 250/4 Nucleodur 100-5 NH2 RP column in less than 10 min. The carbohydrate concentrations were found to range from 24.03 mg/100 g (Zamolxis) to 76.58 mg/100 g (Riviera) for fructose, while the corresponding range was from 52.78 mg/100 g (Zamolxis) to 232.97 mg/100 g (Riviera) for glucose and from 238.41 mg/100 g (Zamolxis) to 378.45 (Cumidava) for sucrose. Chromatographic data were then subjected to chemometric analysis; the association of these complementary techniques allowed a fast selection of cultivars with low-reducing carbohydrate content for food processing purposes-the cultivars Zamolxis, Kronstadt, Christian and Roclas were outlined exhibiting both the lowest reducing carbohydrate content and the lowest sucrose content.

The Effect of Different Substrates on the Morphological Features and Polyols Production of Endomyces magnusii Yeast during Long-Lasting Cultivation.

The study on the influence of different glucose concentrations (2%, 0.5%, and 0.2%) and glycerol (1%) on the morphological and physiological features, as well as the composition of soluble carbohydrates, was performed using Endomyces magnusii yeast. Two-factor analysis of variance with repetitions to process the data of the cell size changes showed that the substrate type affected cell size the most. The cells with 2% glucose were 30–35% larger than those growing on glycerol. The decrease in the initial glucose concentration up to 0.5–0.2% slightly changed the cell length. However, even in the logarithmic growth phase pseudo-mycelium of two to four cells appeared in the cultures when using low glucose, unlike those using glycerol. Throughout the whole experiment, more than 90% of the populations remained viable on all of the substrates tested. The ability for colony formation decreased during aging. Nevertheless, at the three-week stage, upon substrate restriction (0.2% glucose), it was twice higher than those under the other conditions. The respiration rate also decreased and exceeded not more than 10% of that in the logarithmic phase. By the end of the experiment, the cyanide-sensitive respiration share decreased up to 40% for all types of substrates. The study of soluble cytosol carbohydrates showed that the cultures using 2% glucose and 1% glycerol contained mainly arabitol and mannitol, while at low glucose concentrations they were substituted for inositol. The formation of inositol is supposed to be related to pseudo-mycelium formation. The role of calorie restriction in the regulation of carbohydrate synthesis and the composition in the yeast and its biotechnological application is under consideration.

The red alga Tsunamia transpacifica (Stylonematophyceae) from plastic drift shows adaptation to its uncommon habitat in ultrastructure and soluble low molecular weight carbohydrate composition

The recently described red alga Tsunamia transpacifica (Stylonematophyceae) was previously isolated from plastic drift found at the pacific coast, but the natural habitat remains unknown. Here, we investigate ultrastructural details and the low molecular weight soluble carbohydrate composition to get further insight into the adaptation to this uncommon habitat. By means of high pressure freeze fixation, followed by freeze substitution, we could detect an up to 2-µm-thick cell wall surrounded by a distinct layer of extracellular polymeric substances (EPS), likely responsible for the adhering capacities of Tsunamia. The central position of the nucleus and multilobed parietal chloroplast, already observed by light microscopy, could be confirmed. The ultrastructure revealed large electron-dense bodies (EB) in the central cytoplasm, likely resembling degradation products of the chloroplast. Interestingly, these structures contained phosphorous and cobalt, and iron was found in smaller rounded electron-dense bodies by electron energy loss spectroscopy (EELS). Accumulation of these elements suggests a high biosorption activity of Tsunamia. Liquid chromatography-mass spectrometry (LC–MS) data showed the presence of two heterosides (floridoside and digeneaside) together with the polyol sorbitol, which are known as organic osmolytes and compatible solutes. Taken together, these are the first observations on ultrastructural details, element storage and accumulation of protective compounds are contributing to our understanding of the ultrastructural and osmotic solute basis for the ability of Tsunamia to thrive on plastic surfaces.

Could the Content of Soluble Carbohydrates in the Young Shoots of Selected Willow Cultivars Be a Determinant of the Plants’ Attractiveness to Cervids (Cervidae, Mammalia)?

Ten willow cultivars grown in experimental plots were evaluated for performance, attractiveness to foragers, and the content and composition of soluble carbohydrates. The survival of willow cuttings in a thicket and in browse plots differed subject to cultivar, soil quality, and soil moisture content. The number of stump sprouts varied considerably, from 1.1 shoots in the weakest soils in Słonin, Poland, to 3.43 in the plot in Czempin, Poland. Browse plots were established in 2017. They were cut, and fencing was removed in early spring of 2019. Young shoots (10 cm shoot tip with buds, preferably eaten by animals) were sampled for analyses of soluble carbohydrates as potential attractors for foraging cervids. All willow cultivars contained the same soluble carbohydrates: glucose, fructose, galactose, sucrose, myo-inositol, galactinol, and raffinose. Total carbohydrate content ranged from 21.31 (S. amygdalina 1045) to 69.37 mg/g−1 DM (dry matter) (S. purpurea). Glucose was the predominant soluble sugar in the shoots of all willow cultivars, excluding S. viminalis. The fructose content of the shoots was approximately twice lower than their glucose content in all willow cultivars. Smaller differences were observed in the content of myo-inositol, which ranged from 4.61 (S. amygdalina 1045) to 8.26 mg/g−1 DM (S. fragilis cv. Kamon/Resko). The phloem of all willow species contained small quantities of galactinol and trace amounts of raffinose. Weak negative correlations were noted between total carbohydrate content, the content of glucose, fructose, and galactose vs. the attractiveness of willow shoots to foraging cervids. The remaining carbohydrates that occurred in smaller quantities in willow shoots were not correlated with their attractiveness to cervids.

ВПЛИВ ПРАЙМУВАННЯ ГІБЕРЕЛІНОМ ЗА ЯРОВИЗАЦІЇ НА РІСТ ТА ВМІСТ РОЗЧИННИХ ВУГЛЕВОДІВ В ПРОРОСТКАХ ПШЕНИЦІ М’ЯКОЇ

The present study was designed to investigate the influence of gibberellin (GA) priming under vernalization on the growth response, content and fractional composition of soluble carbohydrates in seedlings of 3 varieties of winter wheat - Doridna, Statna and Alians. Modeling different levels of trophic support of the vernalization process and investigating the influence of GA, the following variants were used in the experiments: 1) grains + water (control, optimal trophic support); 2) grains + 10 mg / l GA3, (optimal trophic support); 3) isolated embryos + water (control, lack of trophic support); 4) isolated embryos + 10 mg / l GA3 (lack of trophic support). Vernalization was carried out during 45 days at 4 ° C in Petri dishes on wet filter paper. According to the results, the stimulation of growth processes was identified under the GA effect in all investigated winter wheat varieties. The stimulation occurred as linear growth and biomass accumulation of seedlings, the intensity of which depended on the level of trophic support of these processes. The GA priming in the variant with the lack of trophic support did not significantly stimulate the content of carbohydrates in the varieties Doridna and Statna. It noticeably stimulated the content of carbohydrates in the Alians variety due to changes of oligosaccharides content. The patterns of phytohormonal and trophic regulation of vernalization processes in winter wheat are discussed.

Effects of Sampling Time, Cultivar, and Methodology on Water- and Ethanol-Soluble Carbohydrate Profiles of Three Cool-Season Grasses in Central Kentucky

Cool-season grasses (CSGs) accumulate variable amounts of water-soluble carbohydrates (WSCs, monosaccharides and disaccharides, and fructans), depending on climate, time of day and year, and genotype. Fructan concentrations in CSG are sometimes estimated as the difference between concentrations of WSC and ethanol-soluble carbohydrates (ESCs, monosaccharides and disaccharides, and variable amounts of fructan). Characterizing both WSC and ESC may improve understanding of soluble carbohydrate profiles in pastures and inform grazing management decisions, particularly for horses at risk for laminitis. Three CSG cultivars from Kentucky pastures were collected in the morning and afternoon on two springtime dates. Water-soluble carbohydrates and ESC were extracted with water or 80% ethanol, respectively, and analyzed by high-performance liquid chromatography (HPLC) and a colorimetric assay. Method of analysis (HPLC or colorimetry), and extraction solvent, affected the composition of WSC or ESC determined in CSG samples, demonstrating the need to consider methodology when interpreting results. Total soluble carbohydrate (mean of WSC and ESC) concentrations across cultivars and harvests were generally higher in the afternoon than in the morning, based on both HPLC (P = .0023) and colorimetric (P < .0001) analysis. The diurnal variation was mainly due to sucrose (P < .0001). Among cultivars, monosaccharides and disaccharides constituted the majority of the averaged WSC and ESC concentrations. The proportions of water- and ethanol-soluble fructan (P = .0101), and fructan chain lengths detected in water and ethanol extracts (P < .0001), differed among CSG cultivars. In choosing CSG cultivars for pastures, both soluble carbohydrate composition and concentrations should be considered.

Comparative evaluation of the action of two different endoglucanases. Part II: On a biobleached acid sulphite pulp

A TCF sulphite pulp, bleached at the laboratory scale with a laccase–violuric acid system and complemented with a pressurized hydrogen peroxide stage, was treated with two endoglucanases, one obtained from Paenibacillus barcinonensis (B) and the other one produced from Cerrena unicolor (F) to improve cellulose reactivity. The treated pulps were evaluated in terms of brightness, viscosity, α-cellulose, water retention value, fibre morphology, Fock solubility, NMR and carbohydrate composition of pulps and liquors. Results revealed that both endoglucanases improved cellulose reactivity, albeit in a different way; thus, B caused no scissions in the cellulose chain and no significant reduction in fibre length, whereas F decreased viscosity and shortened fibre length, leading to lower reactivity value. The liquor composition of soluble carbohydrates released by the enzymatic treatments revealed the B had a processive mode of action since short oligosaccharides, cellobiose and glucose, were obtained. F hydrolysed, from high to low concentration, cellobiose, glucose and cellotriose. Importantly, environmentally friendly dissolving pulp with 90 % Fock solubility was obtained, combining two enzymatic treatments: a laccase–mediator system and then a cellulase from P. barcinonensis (B). In order to improve the quality of final dissolving pulp, a pulp purification step was introduced before the B endoglucanase treatment. The cold caustic extraction lead to reduce the amount of hemicelluloses by 42 % with respect to biobleached pulp, but Fock solubility was also reduced. However, complementing the purification step with F treatment, reduced the amount of hemicelluloses but also improved Fock solubility by 17 %, although some presence of cellulose II was detected by NMR.

English

АBSTRACT: General composition of seeds isolated from four Bulgarian grape varieties and their changes during growing was studied. The total content of the main compounds in the seeds was: glyceride oil: 11.6-16.5%; proteins:6.3-8.9%, carbohydrates:65.5-70.9%, ash:2.1-2.8%. The water soluble saccharides were found to be 3.66.3%. The ratio of mono-, di- and trisaccharides was 13.5-19.4%, 70.2-73.8% and 7.1-16.3% respectively. In monosaccharide fraction the main components were fructose (16.2-33.9%), glucose (38.2-44.4%) and galactose (17.6-39.2%). Xylose, rhamnose and arabinose were detected too. In the disaccharide fraction predominated iso-maltose (82.1-91.5%), followed by saccharose and maltose.The changes of the content and composition of soluble carbohydrates in grape seeds during growing were also examined.The content of saccharides decreased relatively from 6.9% in the first to 5.1% in the third stage. The percentage of trisaccharidesrised from 7.1% to 16.3% at the expense of the decrease of the quantity of monosaccharides from19.4% to 13.5% and of the disaccharides from 73.5% to 70.2%. The content of fructose increased from 23.7% to 33.9% at the expense the galactose level which dropped from 32.7% to 17.6%. The increase of the content isomaltosefrom 55.9% to82.1% at the expense of all other disaccharides was detectedin the disaccharide fraction.

Changes in soluble carbohydrates in polar Caryophyllaceae and Poaceae plants in response to chilling

Four species of flowering plants comprising Arctic populations of Cerastium alpinum and Poa arctica var. vivipara and indigenous Antarctic species Colobanthus quitensis and Deschampsia antarctica were investigated. Plants derived from natural origins were grown in an experimental greenhouse in Poland (53°47′N and 20°30′E latitude). Plants for experiment were collected during spring of 2010. Soluble carbohydrates in the intact shoots of C. alpinum and C. quitensis, polar plants of the family Caryophyllaceae, and D. antarctica and P. arctica var. vivipara, representatives of the family Poaceae, were analyzed by gas chromatography, and their involvement in the plants’ response to chilling stress was examined. Plant tissues of the examined families growing in a greenhouse conditions (18–20 °C, short day 10/14 h light/darkness) differed in the content and composition of soluble carbohydrates. In addition to common monosaccharides, myo-inositol and sucrose, Caryophyllaceae plants contained raffinose family oligosaccharides (RFOs), d-pinitol and mono-galactosyl pinitols. RFOs and d-pinitol were not detected in plants of the family Poaceae which contain 1-kestose, a specific tri-saccharide. The accumulation of significant quantities of sucrose in all investigated plants, RFOs in Caryophyllaceae plants and 1-kestose in Poaceae plants in response to chilling stress (4 °C for 48 h with a long day photoperiod, 20/4 h) indicates that those compounds participate in the stress response. The common sugar accumulating in cold stress response and probably most important for chilling tolerance of four investigated plants species seems to be sucrose. On the other hand, the accumulation of above-mentioned carbohydrates during chilling stress can be a return to sugars metabolism, occurring in natural environmental conditions. No changes in d-pinitol concentrations were observed in the tissues of C. alpinum and C. quitensis plants subjected to both low and elevated temperatures, which probably rules out the protective effects of d-pinitol in response to cold stress.

Cyclitols in maturing grains of wheat, triticale and barley

In the present study, the feeding of stem-flag leaf-ear explants of wheat, triticale and barley with d-chiro-inositol and d-pinitol was used for modification of the composition of soluble carbohydrates in grains without genetic transformation of plants. Maturing grains indicated ability to uptake exogenously applied cyclitols, not occurring naturally in cereal plants, and synthesized their a-d-galactosides. The pattern of changes in soluble carbohydrates during grain maturation and germination was not disturbed by the uptake and accumulation of cyclitols. Both, d-chiro-inositol and d-pinitol as well as their a-d-galactosides can be an additional pool of soluble carbohydrates accumulated by maturing grains, without decreasing seeds viability. This is the first report indicating the possibility of introduction of cyclitols with potentially human health benefits properties into cereal grains.

Influence of environment on seed soluble carbohydrates in selected lentil cultivars

High concentrations of raffinose-family oligosaccharides (RFOs) in lentils cause stomach discomfort and reduce lentil quality for human consumption. To develop strategies for lentil quality improvement, we investigated variability, heritability and effects of environmental conditions on the content and composition of soluble carbohydrates in lentil seeds. Analyses of variance showed that cultivar and environment and their interaction had significant effects on the sugar content in lentil seeds. Glucose and sucrose contents of lentil cultivars ranged from 0.02 to 0.06g and 1.22–1.67g100g−1 lentil meal, respectively. Total RFO content of lentil cultivars ranged from 4.5 to 5.5mmol100g−1 lentil seed meal. In all lentil cultivars, RFO content was positively correlated with glucose and sucrose contents. Analysis of RFO profiles by high performance size exclusion chromatography (HP-SEC) showed that stachyose was the major RFO in all lentil cultivars followed by raffinose and verbascose, respectively. The broad sense heritability of sucrose and RFO estimated from the analyses of variance components was 0.89 and 0.85, respectively. Lentil seed RFO content is a highly heritable trait, thus making it amenable to genetic improvement to meet consumer preferences.

Feeding stem–leaf–pod explants of pea (Pisum sativum L.) with d-chiro-inositol or d-pinitol modifies composition of α-d-galactosides in developing seeds

AbstractFeeding stem–leaf–pod explants with d-chiro-inositol and d-pinitol was used as a method to modify α-d-galactosides in developing pea (Pisum sativum) seeds. Four genotypes differing in the composition of raffinose, stachyose and verbascose (raffinose family oligosaccharides or RFOs) in seeds – high RFOs (cv. Tiny), low RFOs (SZD175) and low verbascose (cv. Hubal and cv. Wt 506) – were studied. Although seeds of all examined pea lines were able to take up both d-chiro-inositol and d-pinitol, only d-chiro-inositol was effectively converted into its galactosides: mainly fagopyritol B1 (O-α-d-galactopyranosyl-(1 → 2)-d-chiro-inositol) and fagopyritol B2 (O-α-d-galactopyranosyl-(1 → 6)-O-α-d-galactopyranosyl-(1 → 2)-d-chiro-inositol). In seeds of pea lines naturally containing low levels of verbascose (cv. Hubal) and low RFOs (SZD175), the enhanced accumulation of fagopyritols depressed the RFO level by c. 64 and 20%, respectively. Moreover, in both genotypes, about 25 and 30% of total galactose bound in α-d-galactosides occurred in fagopyritols. d-Pinitol present in the pea seeds was converted into monogalactosides, but their accumulation was several-fold lower than that of fagopyritols and did not significantly influence the accumulation of RFOs. Pea seeds with the composition of soluble carbohydrates modified by feeding with either of the cyclitols were able to complete germination.

Seasonal variation of soluble carbohydrates and starch in Echinolaena inflexa, a native grass species from the Brazilian savanna, and in the invasive grass Melinis minutiflora

Echinolaena inflexa (Poir.) Chase is an abundant C3 grass species with high biomass production in the Brazilian savanna (cerrado); Melinis minutiflora Beauv. is an African C4 forage grass widespread in cerrado and probably displacing some native herbaceous species. In the present work, we analysed seasonally the content and composition of soluble carbohydrates, the starch amounts and the above-ground biomass (phytomass) of E. inflexa and M. minutiflora plants harvested in two transects at 5 and 130 m from the border in a restrict area of cerrado at the Biological Reserve and Experimental Station of Mogi-Guaçu (SP, Brazil). Results showed that water soluble carbohydrates and starch amounts from the shoots of both species varied according to the time of the year, whilst in the underground organs, variations were observed mainly in relation to the transects. Marked differences in the pattern of the above-ground biomass production between these two grasses relative to their location in the Reserve were also observed, with two peaks of the invasive species (July and January) at the Reserve border. The differences in carbohydrate accumulation, partitioning and composition of individual sugars concerning time of the year and location in the Reserve were more related to the annual growth cycle of both grasses and possibly to specific physiological responses of M. minutiflora to disturbed environments in the Reserve border.

Seed α-D-Galactosides of Selected Vicia Species and Enzymes Involved in Their Biosynthesis

We compared the soluble carbohydrate composition of seeds of ten wild and cultivated species of the genus Vicia. In some Vicia species (V. angustifolia, V. grandiflora, V. sativa, V. sepium) they contained only raffinose family oligosaccharides (RFOs) and in others also D-pinitol and its α-D-galactosides. In terms of galactosyl pinitol composition they were divided into three groups: those accumulating small amounts of mono-, di-, tri-galactosyl pinitol A (GPA, ciceritol and TGPA, respectively) and unknown compound (V. sylvatica and V. hirsuta); those accumulating more ciceritol than TGPA (V. tetrasperma and V. villosa); and those accumulating more TGPA than ciceritol (V. cracca and V. tenuifolia). The differences in the activity of galactosyltransferases engaged in RFOs and galactosyl pinitol synthesis confirmed this classification. Seeds of V. angustifolia, naturally accumulating only RFOs, showed an ability to accumulate exogenously applied D-pinitol or D-chiro-inositol and to form the respective α-D-galactosyl cyclitols. Levels of synthesized galactosides depended on the type and concentration of cyclitol in the feeding solution, and seed maturation stage. However, even a high level of D-pinitol or D-chiro-inositol in the feeding solution caused accumulation of only small amounts of mono- and di-galactosyl pinitols, or tri-galactosyl D-chiro-inositol in seeds of V. angustifolia. Enhanced synthesis of galactosyl cyclitols, mainly mono- and di-galactosides of D-chiro-inositol (fagopyritols), clearly reduced production of verbascose. We suggest that exogenously applied free cyclitols inhibit biosynthesis of tri- and di-galactosides and/or cause substrate competition in enzymes of Vicia species.

Imbibitional Chilling Sensitivity and Soluble Carbohydrate Composition of Low Raffinose, Low Stachyose Soybean Seed

Soybean [Glycine max (L.) Merrill] seed with low raffinose, stachyose, and phytin is desired for feeding nonruminant animals to improve feed efficiency, increase mineral uptake, and reduce flatulence, but may have reduced agronomic quality. Composition of soluble carbohydrates in seed parts and sensitivity of mature seed to imbibitional chilling were determined for low raffinose and stachyose (LRS) seed; low raffinose, stachyose, and phytin (LRSP1, LRSP2) seed; and normal raffinose, stachyose, and phytin (CHECK) seed. Cotyledons and axes of seed from the three modified lines had low raffinose, stachyose, and verbascose compared to the CHECK. Cotyledons from LRS seed had significantly higher concentrations of galactinol and the di‐ and tri‐α‐galactoside derivatives of myo‐inositol, d‐pinitol, and d‐chiro‐inositol than cotyledons from LRSP1 and LRSP2 seed. Seed coats of all four lines were similar in soluble carbohydrate composition indicating the modifications were expressed in embryo tissues. Mature seed of LRS and CHECK was tolerant to imbibitional chilling, but LRSP1 and LRSP2 seed were sensitive to imbibitional chilling. The higher accumulation of cyclitol α‐galactosides in embryos (cotyledons) of LRS seed (90% cotyledons, 2% axis, 8% seed coat) may have contributed to imbibitional chilling tolerance.

Soluble carbohydrates in mature soybean seed after feeding d- chiro-inositol, myo-inositol, or d-pinitol to stem-leaf-pod explants of low-raffinose, low-stachyose lines

Soybean [ Glycine max L. (Merrill)] embryos accumulate sucrose, raffinose and stachyose during seed development and maturation. Raffinose and stachyose in soybean feed products are not digested by monogastric animals, resulting in flatulence and fewer nutrients for growth. Three lines of soybean selected for low-raffinose and low-stachyose (LRS) or low-raffinose, low-stachyose and low-phytin (LRSP1, LRSP2) concentrations in mature seed were compared to a CHECK line with normal concentrations of raffinose, stachyose and phytin. To determine if increasing the supply of free cyclitols to developing seed of these lines results in increased accumulation of galactosyl cyclitols, soybean stem-leaf-pod explants of each line were fed solutions containing 10 mM d- chiro-inositol, 10 mM myo-inositol, or 10 mM d-pinitol, or a control solution without cyclitols for 7 days. Explants were air-dried for 14 days. Soluble carbohydrates were extracted from axis, cotyledon, and seed coat tissues of mature, dry seed and analyzed by high-resolution gas chromatography. Axis and cotyledons from mature seed of all modified lines had low concentrations of stachyose compared to the CHECK line when fed a control solution without cyclitols. Feeding d- chiro-inositol to explants increased fagopyritol B1 accumulation in mature seed from all lines. Feeding myo-inositol to explants increased stachyose accumulation in mature seed of LRSP1, but feeding d-pinitol to explants did not alter soluble carbohydrate composition of mature seed. These responses demonstrate that an increase in the supply of free d- chiro-inositol in maternal tissues can result in enhanced accumulation of fagopyritols in mature seed of low-raffinose and low-stachyose or low-raffinose, low-stachyose and low-phytin soybean.

Changes in soluble carbohydrates and starch amounts during somatic and zygotic embryogenesis of Acca sellowiana (Myrtaceae)

Comparative analysis of zygotic and somatic embryogenesis of Acca sellowiana showed higher amounts of sucrose, fructose, raffinose, and myo-inositol in zygotic embryos at different developmental stages than in corresponding somatic ones. These differences were mostly constant. In general, glucose levels were significantly lower than the other soluble carbohydrates analyzed, showing minor variation in each embryo stage. Despite the presence of sucrose in the culture medium, its levels conspicuously diminished in somatic embryos compared with the zygotic ones. Raffinose enhanced parallel to embryo development, regardless of its zygotic or somatic origin. Analysis of the soluble carbohydrate composition of mature zygotic cotyledon used as explant pointed out fructose, glucose, myo-inositol, sucrose, and raffinose as the most important. Similar composition was also found in the corresponding somatic cotyledon. Total soluble carbohydrates varied inversely, decreasing in zygotic embryos and increasing in somatic embryos until the 24th d, at which time they increased rapidly about sixfold in zygotic embryos until the 27th d, a period coinciding with the zygotic proembryos formation. Such condition seems to reflect directly the variation of endogenous sucrose level, mainly because glucose and fructose diminished continuously during this time period. This means that, in terms of soluble sugars, zygotic embryo formation occurred under a situation represented by high sucrose amounts, simultaneously with low fructose and glucose levels, while in contrast, somatic embryo formation took place under an endogenous sugar status characterized by a substantial fructose enhancement. Starch levels increased continuously in zygotic embryos and decreased in somatic ones, the reverse to what was found in fructose variation. Starch accumulation was significantly higher in somatic torpedo and cotyledonary embryos than in the corresponding zygotic ones.

Changes in soluble carbohydrates during storage of Caesalpinia echinata LAM. (Brazilwood) seeds, an endangered leguminous tree from the Brazilian Atlantic Forest

Caesalpinia echinata seeds stored in laboratory environmental conditions lose their viability in one month whilst under low temperatures germination is maintained for 18 months of storage. These seeds are tolerant to desiccation, keeping their viability up to 0.08 gH2O.gDW-1. Since soluble carbohydrates are believed to be involved with desiccation tolerance and seed storability, the aim of this work is to analyze the content and composition of soluble carbohydrates in C. echinata seeds during storage in paper bags (PB) and glass flasks (GF) at laboratory room (RT) and cool (CT) temperatures. In freshly harvested seeds, total soluble carbohydrates comprised approximately 10% of the dry weight, decreasing to ca. 8% over 18 months of storage at RT. In seeds stored at CT, sugars varied differently decreasing initially and being restored at the end of the analysis period. The main neutral sugars in seeds from all treatments were sucrose, fructose and glucose. Raffinose and stachyose were present as traces. Free myo-inositol and other cyclitols were also detected. The main tendency observed was the variation in levels of both glucose and fructose in relation to sucrose, the highest levels of monosaccharides which were found in seeds stored at CT. The values of glucose and fructose were practically constant in seeds stored in paper bags for 18 months at CT, decreasing consistently in the other treatments, mainly at RT. Sucrose contents remained relatively stable. Changes in soluble sugars during storage suggest that the loss of germinability of seeds of C. echinata could be associated with low levels of glucose and fructose in relation to sucrose.