Field-flow fractionation of cationic cellulose derivatives

The asymmetric flow field-flow fractionation (AF4) method was developed for cationic cellulose derivatives. AF4 is the method of choice especially for high-molar mass samples, which are challenging to characterize with conventional chromatographic techniques such as size-exclusion chromatography (SEC). The cationic charge of macromolecules also complicates the size-based separations where no interaction between the analytes and the column stationary phase (SEC) or membrane (AF4) should occur. However, many column matrices and membranes carry negative charge and thus preventing interactions between cationic analytes and negatively charged separation support should be taken into consideration when doing method development. In this study, two eluent compositions, neutral and acidic, were tested for AF4 separation of cationic hydroxyethyl celluloses with varying charge densities. The eluent composition with a pH below the isoelectric point of regenerated cellulose membrane, which was used in this AF4 study, enabled the size-based separation with close to 100% analysis recovery. Macromolecular parameters (molar mass and radius of gyration) and conformation were investigated by coupling a multi-angle light scattering detector and differential refractometer to the AF4 system.Peer reviewe

Yhdyshenkilöverkostosta seutujen päihdetyöhön

Ehkäisevän päihdetyön seutu -hanke, SEUTU-hank

Colloidal features of softwood galactoglucomannans-rich extract

Development of a sustainable bioeconomy requires valorization of renewable resources, such as wood hemicelluloses. The intra- and inter-molecular associations of hemicelluloses within themselves or with other wood components can result in complex macromolecular features. These features exhibit functionality as hydrocolloids, however macromolecular characterization of these heterogeneous materials are challenging using conventional techniques such as size-exclusion chromatography. We studied galactoglucomannans (GGM) -rich softwood extracts at two grades of purity—as crude extract and after ethanol-precipitation. Asymmetrical flow field-flow fractionation (AF4) was optimized and utilized to fractionate size classes in GGM extracts, and subsequent characterization was performed with light scattering and microscopy techniques. Both GGM extracts contained polysaccharides of around 10,000 g/mol molar mass, and colloidal assemblies and/or particles in sub-micron size range. The optimized AF4 method facilitates the characterization of complex biomass-derived carbohydrates without pre-fractionation, and provides valuable understanding of their unique macromolecular features for their future application in food, pharmaceuticals, and cosmetics.Peer reviewe

Environmentally-compatible alkyd paints stabilized by wood hemicelluloses

Wood biorefining currently involves large-scale industrial processes where a notable portion of raw materials, namely hemicelluloses and lignin, are either lost with the process water, degraded, or burnt for energy. Value added utilization of polymeric hemicelluloses is challenging due to their intermediate molar mass and the presence of other wood components, such as phenolic residues or wood extractives. Oil-in-water (O/W) emulsions represent a diverse and abundant class of applications in which the natural properties of wood hemicelluloses are beneficial. In the current work, we present highly promising new technical alkyd paint emulsion systems stabilized with hardwood glucuronoxylans (GX) and softwood galactoglucomannans (GGM). Samples from three isolation methods and their further fractionation by ethanol precipitation were systematically compared with regard to hemicellulose composition, interfacial activity, and functionality in emulsions. Emulsification of alkyd resins was successful with both GX and GGM obtained by various biorefining strategies. The highest emulsion stability over storage was achieved using crude non-purified GX and GGM fractions, and was correlated with the presence of phenolic compounds and extractives, interfacial activity, and small droplet size. Hardwood GX and softwood GGM are envisioned as natural emulsifiers of alkyd O/W emulsions, which are examples of diverse and abundantly-used technical dispersions. This study can be utilized as a guideline for targeted extraction of hemicelluloses with desired functionality, and as a protocol for developing environmentally-compatible industrial dispersions.Peer reviewe

Laccase/TEMPO oxidation in the production of mechanically strong arabinoxylan and glucomannan aerogels

Peer reviewe

Paikallinen alkoholi-, tupakka- ja rahapelihaittojen ehkäisy - Käsikirja yhdessä toteutettavaan Pakka-toimintamalliin

Pakka-toimintamalli on tutkitusti tehokas yhteisöllinen keino paikalliseen alkoholihaittojen ehkäisyyn, mutta se on sovellettavissa myös tupakka- ja rahapelihaittojen ehkäisyyn. Toimintamallissa perinteinen ehkäisevä päihdetyö kohtaa saatavuuden sääntelyn ja vaikuttavuus tehostuu. Toimintamalli nojaa lakeihin ja säädöksiin, jotka ohjaavat ikärajavalvottavien tuotteiden saatavuutta. Toimintamallissa korostuu laaja yhteistyö. Toimijoita ovat kansalaiset, paikalliset poliittiset päättäjät, elinkeino, paikalliset viranomaiset, järjestötoimijat ja media. Samansuuntaisten erillisten toimien vaikuttavuus tehostuu, kun ne tehdään koordinoidusti. Tämä käsikirja on tarkoitettu avuksi Pakka-toimintamallin käynnistämiseen ja toteuttamiseen ehkäisevää päihdetyötä omalla alueellaan tai kunnassaan koordinoiville, johtaville ja kehittäville. Myös muut Pakka-toimintamallin toimijat hyötyvät käsikirjan sisällöistä. Käsikirjan tavoitteena on paitsi kuvata Pakka-toimintamalli niin myös tarjota käytännön vinkkejä ja ideoita toimintaan sekä sen koordinointiin, mutta ennen kaikkea innostaa toimintamallin mukaiseen toimintaan paikallisesti

Extendable blocking probe in reverse transcription for analysis of RNA variants with superior selectivity

Peer reviewe

Interactions between fava bean protein and dextrans produced by Leuconostoc pseudomesenteroides DSM 20193 and Weissella cibaria Sj 1b

The aim of this study was to study the interactions between dextran and fava bean protein. Two dextrans produced by Leuconostoc pseudomesenteroides DSM 20193 and Weissella cibaria Sj 1b were purified and mixed with fava bean protein isolate (FPI) in water or in different buffers. The two isolated dextrans presented a typical dextran structure, mainly alpha-(1 -> 6) linkages (above 95%) and few alpha-(1 -> 3) branches, but they differed in molar mass and conformation. Dry-heating incubation of FPI and dextran mixture facilitated the conjugation of dextran to FPI through the Maillard reaction. Both mixed and conjugated systems were further heat-treated, and different influences of the formed covalent bonds on rheological properties were observed. The W. cibaria Sj 1b dextran had a much higher gel-strengthening ability than the Ln. pseudomesenteroides DSM 20193 dextran. The intermolecular FPI-dextran interactions played an important role in stabilizing the mixed systems at different pH.Peer reviewe