Water-insoluble Part Research Articles

Structural characteristics and potential antidepressant mechanism of a water-insoluble β-1,3-glucan from an edible fungus Wolfiporia cocos

A water-insoluble β-1,3-glucan (Wβ) with a molecular weight of 8.12 × 104 Da was extracted from an edible fungus Wolfiporia cocos. Its backbone was composed of 1,3-β-linked Glcp branched at the C-2, C-4, and C-6 positions, connecting more 1,3-β-linked Glcp with a triple helical structure. Wβ effectively ameliorated depressive symptoms, abnormality of neurotransmitters and inflammatory factors in chronic unpredictable mild stress (CUMS)-induced rats. Wβ also altered the composition of gut microbiota, especially Romboutsia, norank_f_Muribaculaceae and Ruminococcus. Integration of untargeted and targeted metabolomics and Western blotting analysis suggested that the short-chain fatty acids (SCFAs) and tryptophan metabolites were the most important metabolites involved in Wβ mediation. Wβ significantly modulated the levels of 7 SCFAs and 7 tryptophan metabolites, as well as the protein expression of two related enzymes (indoleamine-2,3-dioxygenase: IDO; kynurenine-3-monooxygenase: KMO). Our results suggest that Wβ exerts its antidepressant effect by influencing neurotransmitters and inflammatory factors through interactions between the gut microbiota, SCFA and tryptophan metabolites. The findings offer new insights into water-insoluble polysaccharides, especially β-glucan in structure analysis and utilization, and provide evidence that Wβ, a novel glucan from the often-discarded water-insoluble part of Wolfiporia cocos, has potential application in antidepressant health products.

Formula optimization of herbal drink based on coconut sugar and ginger using the Taguchi method [Optimasi formula minuman herbal berbasis gula merah dan jahe menggunakan metode Taguchi

Increasingly positive public consumption trends have increased demand for functional products such as ginger sugar herbal drinks. However, Micro, Small, and Medium Enterprises (MSMEs) producing ginger sugar herbal drinks still face production challenges, such as relying on traditional recipes passed down through generations with inconsistent processes, which affect quality uniformity. This study aimed to redesign the optimal formulation of ginger sugar herbal drinks based on parameters that affect the process. The method used is the Taguchi method with 4 (four) factors and 3 (three) levels with an L9 (34) orthogonal array matrix. Then, quality parameters were tested to determine the best ginger sugar herbal drink product. The combination of level factors in the optimal formula of ginger sugar herbal drink is the composition of ginger juice 300 mL, brown sugar 700 grams, granulated sugar 500 grams, and cooking time 45 minutes. The results of testing the quality characteristics of the confirmation experiment were following SNI requirements, namely water-insoluble part content 0.84%; water content 4.99%; ash content 1.65%; reducing sugar content 2.48%; sucrose sugar content 81.15%; dissolving time 29.93 seconds; antioxidant activity 67.13 ppm; color sensory properties 5.43; aroma sensory properties 5.32; taste sensory properties 5.16; aftertaste sensory properties 5.53; and overall sensory properties 5.21.Keywords: coconut sugar, ginger, herbal drink, quality, Taguchi method

Impact of TEMPO-Oxidation Pretreatment of Red Ginseng Residual on Nanofibrillation

Red ginseng extract is one of the most widely used herbal medicines to prevent and cure various diseases. Among the processed products derived from red ginseng, the water-insoluble part as red ginseng residual (RGR) becomes waste, even though it contains important ingredients. TEMPO-oxidation (TO) can be used as a pre-treatment with different degrees of oxidation (DO) (0 to 0.4) in red ginseng residual (RGR-TO) by introducing chemical oxidation and high-pressure homogenizer (HPH) as a nanofibrillation process. 1H NMR was used to determine the carbohydrate composition and calculate DO, size was examined using a nanoparticle analyzer, and the zeta potential was used to determine surface charge density. RGR-TO with different concentrations had different compositions; glucose and uronic acid were the main ingredients. All treated RGR-TO showed higher oxidant levels than the untreated counterpart (RGR-TO 0). As the oxidant levels increased, the zeta potential and uronic acid increased, but the size of the nanofibril from RGR-TO decreased. The results of this study showed that TEMPO-oxidation pretreatment was effective in producing RGR cellulose nanofibril (CNF) with a variety of properties by adjusting the level of oxidation pretreatment and the number of HPH passes.

Sensory and Chemical Characteristics of Solid Brem with The Addition of Gedong Gincu Mango Juice (Mangifera Indica L. Var. Gedong Gincu)

Brem is a type of advanced processed food from fermented white glutinous rice. This study aims to determine the characteristics of solid brem with the addition of Gedong Gincu mango juice. This research uses a one-factor, completely randomized design (CRD) with three levels of treatment with a comparison of white sticky tape juice and Gedong Gincu mango juice, namely A1 (85%:15%), A2 (75%:25%), and A3 (65%:35%). As well as testing paired T-tests for selected products and control. The data analysis used is ANOVA with Duncan advanced test (α=0,05). Based on the results of research solid brem addition of Gedong Gincu mango juice affects the sensory quality (color (3,53-8,44), flavor (5,61-6,79), and appearance (5,44-7,85)), hedonic (color (4,97-7,29), aroma (6,04-7,30), texture (6,34-7,79), and overall (6,41-7,53)), and chemical (water content (18,31%-20,71%), carbohydrates as starch (2,63%-9,17%), acidity (9,51%-17,85%), and vitamin C (2,25 mg/100g-3,02 mg/100g)). However, the addition of Gedong Gincu mango juice did not affect the sensory quality (aroma (5,92-6,45), taste (6,77-7,60), and texture (7,41-7,75)), hedonic (taste (6,34-7,16)), and chemical (ash content (1,45%-4,06%), and water-insoluble part (3,61%-4,15%)). Further test results T-test sample A1 and control showed parameters of color, aroma, and appearance (sensory quality); color, aroma, and taste (hedonic); and the value of water content, ash content, carbohydrates, acid degrees, and vitamin C has no significant effect with the addition of Gedong Gincu mango juice. In contrast, the parameters of taste, flavor, texture (sensory quality), texture and overall (hedonic), and water-insoluble part significantly affect the addition of Gedong Gincu mango juice

Pyrogallol is a key component for xanthine oxidase inhibition by the leaves of Ammannia baecifera

Ammannia baecifera Linn is an important plant in traditional medication system of Bangladesh. In order to give the scientific clarification for using this plant in the treatment of gout, this study was designed to identify the xanthine oxidase (XO) inhibitors present in the extract of Ammannia baecifera leaves along with evaluating its antioxidant effect. First aqueous extract was prepared from leaves and then water insoluble part (WIP) was separated from water soluble part (WSP) as precipitate with ethanol. In DPPH and ABTS assays, WSP with rich amount of phenolic compound exhibited high radical scavenging activity than WIP. WSP also showed potent XO inhibition with IC50: 18.03 ± 1.65 μg/mL value. Using different chromatographic techniques, the key XO inhibitor was isolated from WSP and identified as pyrogallol based on its different spectroscopic data. In XO inhibition assay, pyrogallol (IC50: 11.67 ± 0.45 μg/mL) showed potent inhibitory effect as compared to a known XO inhibitor (allopurinol; IC50 = 27.35 ± 1.15 μg/mL) and it also displayed strong DPPH and ABTS radical scavenging effect. In addition, an inhibition kinetics study indicated that WSP and pyrogallol are mixed competitive inhibitors of XO. The overall results suggest that the presence of pyrogallol as XO inhibitor and free radical scavenger in Ammannia baecifera leaf justifies the traditional uses of this plant.
 Keywords: Ammannia baecifera, Leaves, Xanthine oxidase, Pyrogallol, Inhibitor

Characterization of Salt Quality from Artemia (Artemia franciscana) Cultured Water with Dunaliella salina as Natural Feed

The high demand for domestic salt cannot be achieved by local salt production from traditional salt and PT. Garam fluctuates every year. In addition, the quality of traditional salt is still low. This causes the need for domestic salt consumption to be met by imported salt. Therefore, it is necessary to have an alternative to meet the domestic salt demand, namely the revitalization of salt ponds for the development of mass Artemia cultivation that produces both Artemia production and biomass and produces salt in one location. In its natural habitat, Artemia uses microalgae as its main food source. The quality of microalgae feeds greatly determines the production of Artemia franciscana. The availability of nutrients is a factor that determines the rate of growth, so the amount and quality of feed are the main factors to meet the nutritional content for optimal development. Therefore, the salt production in this study used saltwater cultured Artemia with Dunaliella salina as a natural feed with a water age of 3rd,7th, and 14th days. This study aimed to determine the best age of Artemia water cultured with Dunaliella salina as a natural feed in salt production. The results showed that the different ages in Artemia water cultured with Dunaliella salina had a significant effect (p < 0.05) on salt characteristics. The best result was D7 which is salt from Artemia cultured water with Dunaliella salina as a natural feed with water age 7th day. Their respective values are 0.66a + 0.33 water content, 91.55 + 0.32 NaCl, 0.87 water-insoluble part, 0.39% + 0.01 Ca, and 1.25a + 0.05 Mg.

Fractionation of the water insoluble part of the heterotrophic mutant green microalga Parachlorella kessleri HY1 (Chlorellaceae) biomass: Identification and structure of polysaccharides

The water-insoluble part of Parachlorella kessleri HY1 biomass was subjected to the extraction of cell-wall polysaccharides using polar aprotic solvents (DMSO, LiCl/DMSO) and aqueous alkaline solutions (0.1, 1 and 4 mol·l−1 of NaOH). Proteins predominated in all the crude extracts and in the insoluble residues were partially removed by treatment with proteolytic enzymes (pepsin and pronase), and in some cases with the HCl/H2O2 reagent, yielding purified polysaccharide-enriched fractions. These treatments led to the solubilisation of some products in water. The composition and structure of isolated polysaccharides were characterised based on monosaccharide composition, glycosidic linkage and spectroscopic analyses. The DMSO extract contained mainly proteins, and polysaccharides were not detected. The water-soluble parts isolated from the LiCl/DMSO extract contained α-l-rhamnan, α-d-glucan and β-d-glucogalactan; the water-insoluble part contained (1 → 4)-β-d-xylan, first isolated from the biomass of green microalgae. The alkali extracts contained polysaccharides of similar structure, and also water-insoluble (1 → 4)-β-d-mannan. The insoluble part after all extractions contained α-chitin as the main polysaccharide, which was confirmed by spectroscopic methods. All these polysaccharides can play a certain role in the cell wall structure of this microalga.

Inhibitory effect of Ammannia bacifera leaves against lipase and angiotensin-converting enzyme

Obesity and hypertension are multifactorial problems that are responsible for causing several life-threatening diseases. The occurrence of obesity and hypertension is increased day by day and so the remedies from natural sources are recognized as valuable tools to control obesity and hypertension with the minimum side effects. With realizing this fact, this study was designed to evaluate the inhibitory potential of Ammannia baecifera leaves against pancreatic lipase and angiotensin-converting enzyme (ACE). First water soluble part (WSP) of crude aqueous extract prepared from leaves of Ammannia baecifera was separated from water insoluble part (WIP). In lipase inhibition assay, a moderate inhibitory effect of WSP was observed against pancreatic lipase with a IC50 value of 4.39 ± 0.48 μg/mL whereas WSP showed strong inhibitory effects against ACE (14.23 ± 0.82 μg/mL) as compared with captropil (12.54 ± 0.85 μg/mL). In case of both enzymes, WIP did not show any activity. Therefore, this study suggests that Ammannia baecifera leaves might be a prospective therapeutic agent for the management of obesity and hypertension.

Screening of the Chemical Composition and Identification of Hyaluronic Acid in Food Supplements by Fractionation and Fourier-Transform Infrared Spectroscopy.

Hyaluronic acid, together with collagen, vitamins or plant extracts, is a part of many cosmetic and food preparations. For example, this polysaccharide is used in formulation of many food supplements due to its protective effects on human health. In this work, the screening of the chemical composition of three chosen dietary supplements (powder, tablets and capsules) containing hyaluronic acid was carried out using Fourier-transform infrared spectroscopy. Because of the low amount of analyte in all these samples, it was isolated or concentrated prior to the analysis using a suitable sequential fractionation protocol. Individual isolation procedures were established for each sample based on their declared composition. Firstly, the major components such as collagen or vitamins were removed to obtain polysaccharide fractions by the enzymatic treatment and/or washing out with the appropriate solvents. In some cases, the water insoluble part was removed from the rest dissolved in water. Then, hyaluronic acid was precipitated with copper(II) cations and thus separated from the other polysaccharides. Finally, the analyte was identified in the enriched fractions by the characteristic vibrational bands. The amount of hyaluronic acid in the purified fractions was determined in three ways: gravimetrically, spectrophotometrically, and using isotachophoresis. The combination of the appropriate preparative and analytical steps led to the successful evaluation of chemical composition, finding and quantification of hyaluronic acid in all the studied samples.

Langmuir and Langmuir–Blodgett films of aromatic amphiphiles

ABSTRACT Amphiphiles are molecules that contain two discrete segments – a water-soluble hydrophilic part (head-group) and a water-insoluble hydrophobic part (tail). The structural variations possible with the head-group part are enormous and numerous amphiphiles have been designed in this way. On the other hand, the structural variations feasible for the hydrophobic tail part are rather limited. Saturated aliphatic hydrocarbon chains are predominantly found in most of the amphiphiles. Unsaturated aliphatic hydrocarbon chains (n-alkenyl or n-alkynyl chains) also serve as the hydrophobic tail part in many of the amphiphiles. Amphiphiles, wherein the hydrophobic tail part is made up of aromatic moieties (alone or in combination with aliphatic chains) are less frequently encountered compared to the other two types. Many of these aromatic amphiphiles, the focus of this review article, are known to form different types of assemblies including Langmuir and Langmuir-Blodgett (LB) films. In this review, we will provide an account of the different types of aromatic amphiphiles that have been reported and highlight their properties and applications at the air–water and air–solid interfaces.

One-sided phosphoric fertilizers based on off-balance ore of phosphorites of the central kyzyl kum and their water-insoluble part

One-sided phosphoric fertilizers based on off-balance ore of phosphorites of the central kyzyl kum and their water-insoluble part

Chemical composition of single-sided phosphoric fertilizers obtained from balanced phosphorite ore of central kyzylkum by phosphoric acid activation with sulfuric acid addition

In this study, the process of activation of off-balance phosphorite ore of the Central Kyzylkum desert (14,33% P205) by extraction phosphoric acid (14,32% P205) with the addition of sulfuric acid (93%) at 75 °C, reaction time 30 min. at different mass ratios P205PAE: P205FC andP205PAE : H2SO4mng. It is shown that the addition of H2SO4 significantly intensifies the process of phosphoric acid activation of the phosphate mineral of the raw material. The water-insoluble part of the products of phosphoric acid activation with the addition of sulfuric acid has been studied. It has been shown that both the fertilizer itself and it’s water-insoluble part contain a significant amount of the P2O5 form assimilable for plants.

Facile Screening of Various Micellar Morphologies by Blending Miktoarm Stars and Diblock Copolymers.

A time-saving phase-diagram screening is introduced for the self-assembly of miktoarm star polymers with different arm numbers for the insoluble part. Agreeing with theory, all conventional micellar morphologies (spherical star-like micelles, cylindrical micelles and vesicles) can be accessed by adjusting the average arm number when blending miktoarm stars with diblock copolymers (at constant arm/block lengths). Additionally, a rare clustered vesicle phase is detected. Hence, this approach permits an easy tuning of the equilibrium morphology and the size of the solvophobic domain. Such screening by scattering, ultracentrifugation, and electron microscopy techniques assists the targeted synthesis of miktoarm stars with a well-defined arm number, aimed at the morphology control of the nanostructures without blending. Specifically, we demonstrate a systematic variation of all classical micellar morphologies based on interpolyelectrolyte complexes (IPECs), consisting of a water-insoluble part formed by electrostatically coupled poly(styrenesulfonate) chains/quaternized poly(2-(dimethylamino)ethyl methacrylate) blocks, being stabilized by hydrophilic poly(ethylene oxide) blocks.

Changes in Turbidity, Zeta Potential and Precipitation Yield Induced by Persian Gum-Whey Protein Isolate Interactions During Acidification

To measure the molecular parameters of Persian gum (PG) (gathered from Kazeroon plains/Iran) by gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), water-insoluble part of gum was removed using filtration method. In the following, acidification of whey protein isolate/PG mixture solutions (pH ∼ 7.00–2.00) at different biopolymer mixing ratio (r = 0.1–10) was induced by HCl, allowing turbidity, zeta potential and precipitation yield determinations. Contrary to previous studies, it was demonstrated that more than 93% of gum is composed of large water-insoluble particles and water-soluble part contains heavy and heterogeneous compounds with high weight-average molecular mass (up to 5.11 × 106 g/mol) and high dispersity index (∼2.54–6.64). Acid titration of the mixtures displayed that the net neutrality shifts to the higher pHs by increasing the mixing ratio, and the charge neutralization occurs at pHs near pHopt as well. Generally, the maximum interaction was found for a 1:1 WPI/PG mixture with the highest liquid precipitate yield achieved at pH 3.4. Practical Application Persian gum exudes from the wild almond tree (Amygdalus scoparia), growing in the Middle East countries. The characteristics of this hydrocolloid highly depend on the color of exudate and region of the tree. As a mixture with gum Arabic, it has wide industrial and pharmaceutical applications due to economic reasons and high functionality. However, very few scientific information about this gum has been already published. Some researchers have displayed the emulsifier, stabilizer and fat replacer ability of this gum. The interaction of PG with other biopolymers such as proteins would be beneficial in food and pharmaceutical applications in the form of gels, microcapsules, etc. In this study, we have measured the water-soluble and insoluble fractions and molecular parameters of PG gathered from Kazeroon plains. To have a basic knowledge for our future investigations on encapsulation ability of PG-WPI complexes, titration method was applied for different PG-WPI admixtures.

Antioxidant potential of Juglans regia bark: quantification of seven phenolic compounds by RP-HPLC

Walnut (Juglans regia L., Juglandaceae) is traditionally used for the treatment of various common ailments including tuberculosis, tuberculosis of the cervical glands, and cancer [1, 2]. The bark of J. regia contains juglone along with numerous bioactive polyphenols [3, 4]. Although there have been many reports on several biological activities of J. regia bark [2–5], there has been only one report on its antioxidant activity [3]. The objectives of this work were to determine the antioxidant potential and bioactive compounds of the methanol extract (MOH) and its fractions obtained by partitioning from J. regia bark with hexane (HEX), chloroform (CHL), ethyl acetate (EA), and butanol (BU), and the water-insoluble part (INS). Methanol is able to extract out a significant amount of compounds (11.36%) from the walnut bark. The yields of fractions were: EA-3.18, BU-1.87, CHL-0.21, and HEX-0.11%, suggesting that ethyl acetate is a more effective solvent for fractionation. Some phenolic compounds also remained trapped in the water-insoluble part (INS, 1.4%). Total phenol content (TPC), determined using Folin–Ciocalteau reagent [6], was highest in the EA (470.3 ± 8.5) followed by BU (360.5 ± 4.8), MOH (343.5 ± 5.5), INS (193.4 ± 2.8), CHL (100.2 ± 3.5), and HEX (32.3 ± 2.3), all in mg g–1 dry extract. In a study, Labuckas and co-workers [7] has reported high total phenol content in aqueous-methanolic extract of hull of J. regia. The antioxidant activity of the extract and fractions were determined by DPPH (2,2'-diphenyl-1-picrylhydrazyl) [8], ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) [9] radical scavenging and FRAP (ferric reducing/antioxidant power) [10] assays, and the results are presented in Table 1. The EA showed highest antioxidant potential in three in vitro test systems. Both EA and BU were better DPPH scavengers than the positive control quercetin; however, none of the extract/fractions were as effective as butylated hydroxytoluene (BHT) or gallic acid. ABTS∙+ scavenging of extract/fractions was also much lower than gallic acid, BHT, and quercetin. In contrast to DPPH∙ scavenging, ABTS∙+ scavenging ability of the marker compound juglone was much higher than the extract or fractions. The reducing power of EA was found comparable to the positive controls quercetin and BHT. However, it was much lower than gallic acid. The reducing power of juglone was significantly lower than that exhibited by the extract or fractions except HEX and CHL. It was also noticed that the order of DPPH∙ scavenging and ferric reducing properties of the extract and fractions was similar to the order of TPC. This indicates that there is a significant correlation between antioxidant properties and TPC. The correlation coefficients (r2) of total phenolic content, DPPH∙ and ABTS∙+ scavenging, and FRAP activities were 0.975, 0.798, and 0.960, respectively. In order to quantify phenolic compounds in the extract/fractions, HPLC was carried out using a LiChrospher RP-18 column (250 mm х 4.6 mm, 5 μm) and Waters 2996 photodiode array detector at 30 degree C. a) Acetonitrile–methanol (70:30, v/v) and b) 0.05% trifluoro acetic acid were used as the mobile phase with a gradient programmed as follows: a) 80–0% in 0–10 min and back to 80% in 20 min with a flow-rate of 1 mL/min. Seven phenolic compounds, namely gallic acid (1), caffeic acid (2), quercitrin (3), rutin (4), myricetin (5), quercetin (6), and juglone (7), were quantified. Among all, quercitrin and gallic acid were observed in the highest amount in the MOH and its fractions (Table 2). In particular, the content of each phenolic compound was higher in EA in comparison to others, which corroborated with the observed trends in total phenol content and antioxidant activity. The marker compound juglone was detected only in the methanol extract and not in the fractions. The results of this study clearly indicate that walnut bark extract/fractions, especially the ethyl acetate fraction, may be used as a potential source of natural antioxidant.

Decomposition of plant residues of different quality in soil—DAISY model calibration and simulation based on experimental data

A parameter setup for the DAISY model calibrated on data measured in the field was evaluated on data obtained from a lab-incubation experiment with residues of leguminous green manure plants, blue grass, rape straw and barley straw. The aim of this study was to test and further develop the principles and parameters for the turnover and the initial characterisation of these plant materials in the DAISY model. The field-calibrated parameter set led to considerable problems when applied to the lab-incubation experiment. For mineral N, soil microbial biomass N and added organic matter, none of the model simulations was fully satisfactory. The only exception was the treatment without addition of plant material. As a consequence, the parameters controlling the turnover of added organic matter and soil microbial biomass have been modified. Further conceptual changes have been suggested. It was not possible to simulate the initial decay and N release from added organic matter (AOM) by simply subdividing it into a water-insoluble part (AOM1) and a water-soluble part (AOM2). However, the C/N ratio and the cellulose content of the added plant residues may be useful indicators for the partitioning of plant materials into a slowly decomposable (AOM1) and a rapidly decomposable (AOM2) part. The general concept of two AOM-pools with predefined constant turnover rates and C/N ratios is questioned for plant residues with very different properties. After addition of easily decomposable green plant materials, death and maintenance respiration rates of modelled soil microbial biomass pools had to be reduced considerably in order to fit simulated mineral N to measured values. This is in contrast to the assumption of two SMB-pools with different but constant properties. After these modifications it was possible to achieve reliable simulations of mineral N, cumulative soil respiration and added organic matter. However, a major problem remained after recalibration. It was not possible to simulate SMB-N satisfactorily in the treatments with red clover, white clover or white melilot. It is concluded that the DAISY model does not fully reflect the flow of N through SMB after addition of easily decomposable leguminous plant materials and the following turnover into soil microbial residual N (SMR-N). The introduction of a separate SMR-pool is proposed.

Chemical speciation of individual atmospheric particles using low- Z electron probe X-ray microanalysis: : characterizing “Asian Dust” deposited with rainwater in Seoul, Korea

Chemical speciation of individual microparticles is of much interest in environmental atmospheric chemistry; e.g. the determination of the elemental concentrations in individual atmospheric aerosol particles is important to study the chemical behavior of atmospheric pollution. Recently, an EPMA technique using an X-ray detector equipped with an ultra-thin window, allowing EPMA to determine concentrations of low- Z elements, such as C, N, and O, in individual particles of micrometer size, has been developed. This technique, called low- Z electron probe X-ray microanalysis (low- Z EPMA), is applied to characterize the water-insoluble part of “Asian Dust”, deposited by washout in the form of rainwater during an Asian Dust storm event and collected in Seoul, Korea. In this study, it was demonstrated that the single particle analysis using low-Z EPMA provided detailed information on various types of chemical species in the sample. In addition to aluminosilicates, silicon oxide, iron oxide, and calcium carbonate particles, which are expected to be present, carbonaceous particles are also observed in a significant fraction. This unexpected finding that particle sample originated from an arid area contains significant amount of carbonaceous particles is supported by the investigation of a “China Loess” sample. In addition, we also performed single particle analysis for a local soil sample, in order to check the possible influence from local sources on “Asian Dust”. The characteristics of the local soil particle sample, e.g. the types of aluminosilicate particles and the abdundance of particles with deviating chemical species, are clearly different from “Asian Dust” and “China Loess” samples, whereas those two are similar, implying that the “Asian Dust” sample was not much influenced by local sources.

Lemon albedo cell walls contain distinct populations of pectic hairy regions

Alcohol insoluble solids from lemon albedo were extracted to obtain a chelating agent soluble pectin fraction (ChSS), a diluted sodium hydroxide soluble pectin fraction (ASS) which was separated into a water soluble and water insoluble part (ASSws and ASSwi), and an insoluble residue (Residue). ChSS, ASSws, ASSwi and Residue represented 64.3%, 10.4%, 0.4% and 8.1% of the galacturonic acid residues present in the lemon albedo, respectively. The pectin fractions and the residue were characterised by their sugar composition, degrees of methylation and acetylation, and molecular weight distribution. After extensive digestion with polygalacturonase and pectinesterase, the remaining high molecular weight fragments, representing the so-called pectic hairy regions (HR), were isolated and further characterised. After cold alkaline treatment (de-esterification), HR shown to be accessible to a further degradation by rhamnogalacturonan hydrolase (RGase) and the digests were analysed by high-performance size-exclusion chromatography (HPSEC) and high-performance anion-exchange chromatography (HPAEC). The various HR fractions differed in their degradation pattern: typically 2–4% of all glycosidic linkages were hydrolysed. The amount of RGase oligomers formed from the various fractions decreased in the order these were extracted while the degree of galactose substitution of the oligomers increased. Indications were found for the presence of small quantities of xylogalacturonan fragments within the pectic hairy regions of lemon albedo. On the basis of these results the structure of lemon pectin is compared with the structure of pectins extracted from other sources.

On the thread-like morphology of LC/I block copolymers in nematic solvents

AB and ABA block copolymers are synthesized by direct living anionic polymerization where the A-block is a liquid crystalline side chain polymer (LC-block) and the B-block is an isotropic polymer (I-block). Similar to amphiphilic block copolymers with a “hydrophilic” water soluble segment and a “hydrophobic” water insoluble part, the LC/I block copolymers consist of the “nematophilic” LC-block that is soluble in a nematic solvent and the “nematophobic” segment that is insoluble in nematic solvents. The behaviour of these LC/I block copolymers and corresponding homopolymers is analyzed in dilute nematic solutions of low molar mass liquid crystals. The effects of varying molecular weight, chemical constitution of blocks and block length ratio are investigated. Copolymers with a high fraction of the I-block are insoluble in the nematic solvent as indicated by phase separation. Copolymers with a high fraction of the LC-block are completely soluble. If the weight fraction of the LC-block is in the range of 0.46 to 0.85, thermoreversible thread-like aggregates are formed in the nematic solvent. These thread-like aggregates have a uniform diameter of 2–3 μm and their long axis perfectly follows the director field of the nematic matrix. The formation of these structures is discussed in terms of copolymer concentration, temperature and influence of aligning surfaces. From simple geometrical packing arguments it can be assumed that these thread-like aggregates consist of bilayered vesicles. In contrast to the spherical shape of amphiphilic block copolymer vesicles in aqueous solution, the rod-like shape of vesicles in nematic solution is caused by the minimization of free elastic energy density of the nematic matrix.

On the thread-like morphology of LC/I block copolymers in nematic solvents

AB and ABA block copolymers are synthesized by direct living anionic polymerization where the A-block is a liquid crystalline side chain polymer (LC-block) and the B-block is an isotropic polymer (I-block). Similar to amphiphilic block copolymers with a “hydrophilic” water soluble segment and a “hydrophobic” water insoluble part, the LC/I block copolymers consist of the “nematophilic” LC-block that is soluble in a nematic solvent and the “nematophobic” segment that is insoluble in nematic solvents. The behaviour of these LC/I block copolymers and corresponding homopolymers is analyzed in dilute nematic solutions of low molar mass liquid crystals. The effects of varying molecular weight, chemical constitution of blocks and block length ratio are investigated. Copolymers with a high fraction of the I-block are insoluble in the nematic solvent as indicated by phase separation. Copolymers with a high fraction of the LC-block are completely soluble. If the weight fraction of the LC-block is in the range of 0.46 to 0.85, thermoreversible thread-like aggregates are formed in the nematic solvent. These thread-like aggregates have a uniform diameter of 2–3 μm and their long axis perfectly follows the director field of the nematic matrix. The formation of these structures is discussed in terms of copolymer concentration, temperature and influence of aligning surfaces. From simple geometrical packing arguments it can be assumed that these thread-like aggregates consist of bilayered vesicles. In contrast to the spherical shape of amphiphilic block copolymer vesicles in aqueous solution, the rod-like shape of vesicles in nematic solution is caused by the minimization of free elastic energy density of the nematic matrix.