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Emulsions are commonly used to fortify beverages with oil-soluble nutrients. Such emulsions must be physically stable, prevent the cargo nutrient from chemical degradation, and release the nutrient at the right time during digestion. Wood hemicelluloses, with their proven capability in producing nanoemulsions and preventing oil oxidation, have the potential to facilitate such a fortification method. These hemicelluloses are unique, as the presence of residual lignin was proven essential in their functionality. However, the structural interplay between the residual lignin and the polysaccharide fraction at the oil-water interface is unknown, including their effects on the storage stability and digestibility of a loaded bioactive compound. We studied the performance of emulsions stabilized by two grades of birch glucuronoxylans (GX) as vessels for vitamin D3. Both GXs showed similar protective performance to methylcellulose regardless of the lignin content during storage and the gastric phase of digestion. The unrefined GX, which contained larger lignin moieties, delayed the release of vitamin D3 during intestinal digestion. We concluded that the interface is primarily built of a polysaccharide layer with the lignin moieties facing towards the oil phase. We have thus highlighted the potential of GX-stabilized emulsions as carriers of vitamin D3. Additionally, these results advance the understanding of lignin-polysaccharide interplay towards a rationalized strategy in biorefining of wood hemicelluloses, for which the ratio of lignin-to-polysaccharide can be adjusted during extraction and post-extraction treatments to obtain a tailor-made emulsifier for various emulsion-based products. [Display omitted] • Vitamin D3 was stable in glucuronoxylans-based emulsions over 5 weeks. • Larger lignin moieties affected vitamin D3 release but not its storage stability. • The polysaccharide fraction formed the bulk of the interfacial layer. • The polysaccharide fraction faced the aqueous phase, while lignin faced the oil. [ABSTRACT FROM AUTHOR]

Galactoglucomannans (GGM) recovered from abundant forest industry side-streams has been widely recognized as a renewable hydrocolloid. The low molar mass and presence of O -acetyl side-groups results in low viscous dispersions and weak intermolecular interactions that make GGM unsuitable for hydrogel formation, unless forcefully chemically derivatized and/or crosslinked with other polymers. Here we present the characterization of hydrogels prepared from GGM after tailoring the degree of acetylation by alkaline treatment during its recovery. Specifically, we investigated gel characteristics of low-acetyl GGM dispersions prepared at varied solid concentrations (5, 10 and 15 %) and pH (4, 7 and 10), and then subjected to ultrasonication. The results indicated that low-acetyl GGM dispersions formed gels (G′ > G″) at all other studied solid concentration and pH level combinations except 5 % and pH 4. High pH levels, leading to further removal of acetyl groups, and high solid concentration facilitated the gel formation. GGM hydrogels were weak gels with strong shear-thinning behavior and thixotropic properties, and high hardness and water holding capacity; which were enhanced with increased pH and solid concentration, and prolonged storage time. Our study showed the possibility to utilize low-acetyl GGM as mildly processed gelling or thickening agents, and renewable materials for bio-based hydrogels. [Display omitted] [ABSTRACT FROM AUTHOR]

This work was aimed at studying the effect of wood galactoglucomannan hemicelluloses (HC) on the recovery of copper and molybdenum from a high clay ore. The performance of HC was compared with the results obtained using carboxymethyl cellulose (CMC). Results indicated that HC has a stronger effect than CMC to increase the recovery of Cu from a high clay ore, but a higher depressing effect on the recovery of Mo. At 230 ppm of HC copper recovery increases 7.6 percentage points and Mo recovery decreased 20.7 percentage points respect to samples floated without HC. Thus the use of HC and CMC to improve copper recovery in the flotation high clay copper ore appears to be very promising, but considerations must be done when treating molybdenum rich ores. Due to the fact that HC are semi-amorphous with side hydroxy group on the chain, one possible mechanism of adsorption may be related to hydrogen bonds existing between these hydroxy groups and the surfaces of the clay mineral particles. Further studies that include tests to clarify the mechanisms of adsorption of HC on clay minerals and valuable species, as well as the effect of this reagent on other types of high clay ores are necessary in the future. [ABSTRACT FROM AUTHOR]

• Macromolecular analysis of spruce galactoglucomannans (GGM)-rich extract was performed. • AF4 parameters for efficient fractionation of crude polysaccharide extract were studied. • GGM extracts were found be a colloidal mixture of polysaccharides and particles/aggregates. • Presence of colloidal particles depended on purity of GGM extract. Development of a sustainable bioeconomy requires valorization of renewable resources, such as wood hemicelluloses. The intra- and inter-molecular association 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. [ABSTRACT FROM AUTHOR]