The quest for sustainable materials has stimulated extensive research into biobased carbon fibers, with lignin–cellulose composite fibers emerging as promising candidates. However, challenges persist, for example, the leaching of lignin during fiber spinning, which limits the process efficiency and carbon fiber yield. Thus, this work aims to understand the causes and the impact of lignin leaching. The lignin was varied in terms of source, extraction technique, and molecular weight, and the lignin yield, fiber morphology, and mechanical performance of cellulose–lignin composite fibers were elucidated. The results demonstrated that the lignin’s functional groups significantly influence lignin yield in spun fibers, and a high molecular weight is beneficial. An expressive decrease in lignin yield was observed for lignin with a higher content of polar functional groups such as carboxylic acid groups and a lower content of condensed lignin moieties. Furthermore, leaching of lignin was also associated with the observed defects and deteriorated mechanical properties of the precursor fiber. Addressing these challenges is thus critical for maximizing the potential of biobased carbon fibers, emphasizing the need to mitigate lignin leaching and optimize fiber processing parameters for enhanced fiber quality and performance

Liposomes and lipid nanoparticles (LNPs) are central to modern drug‑delivery strategies, yet their reliable characterisation remains challenging due to their structural complexity and the limited availability of harmonised analytical standards. In this study, we assess an extensive set of established and novel dimensional, structural, and chemical characterisation methods across a panel of well‑defined LNP formulations and two liposomal systems with distinct compositions and stabilisation mechanisms. Cryogenic transmission electron microscopy provided direct visualisation of particle morphology and lamellarity, revealing clear structural differences between homogeneous, predominantly unilamellar liposomes and heterogeneous, multilamellar liposomes, and confirming the structural consistency of LNP samples. Dimensional methods for particles in fluids generated complementary size metrics and highlighted differences in resolution as well as method‑dependent artefacts, particularly for polydisperse samples. Among these, small angle X-ray scattering unlocked structural information including bilayer thickness and multilamellar spacing under native liquid conditions, while ribonucleic acid (RNA)-specific assays provided robust quantification of total and encapsulated RNA. Advanced electron- and mass‑spectrometric techniques, delivered additional insight into surface chemistry and, critically, enabled molecular‑level analysis at the single‑particle scale. Together, these results show that no single technique can fully capture the complexity of lipid‑based delivery systems. Instead, a metrologically informed, multimodal approach is essential for generating reliable, reproducible datasets and for supporting the development of future standards for the characterisation and quality control of nanomedicine formulations

Food emulsions are complex colloidal systems whose structural and molecular properties critically influence stability and sensory attributes. This study combines cryogenic time-of-flight secondary ion mass spectrometry (cryo-ToF-SIMS) with transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) to characterize the chemical and structural properties of bovine milk, cream, and an oat-based cream analogue. Cryo-ToF-SIMS enabled parallel mapping and spatial correlation of multiple molecular components, including fat, proteins, calcium, phospholipids and sugars, in microscopic structures, such as fat globules and interstitial elongated aggregates, which were structurally characterized at the nanometer level with TEM. ToF-SIMS correlation analysis revealed significant differences in the molecular composition of the interstitial aggregates, with considerably less mixing of components in the oat-based cream analogue. In addition, 3D analysis of individual milk fat globules generated depth profiles of calcium and proteins at the surface of fat globules, consistent with casein binding to the surface of the protein-containing milk fat globule membrane (MFGM). Furthermore, the triglyceride content of the fat globules were characterized using mass spectra from ToF-SIMS and found to be consistent with the reported fatty acid distributions in Swedish cow milk for bovine milk and cream, and in rapeseed oil for oat-based cream analogue

In plant-based products made to mimic meat it is sought after to include fat to enhance flavor and texture based on healthy plant-based oils. Oleogels have gained interest as way of structuring oils. However, understanding how the crystalline network affects long-term stability and oil mobility remains limited. In this study, rapeseed oil oleogels containing 10 % (w/w) of either candelilla wax, beeswax, or rice bran wax were investigated. We combined low-strain rheo-microscopy, differential scanning calorimetry (DSC), and fluorescence recovery after photobleaching (FRAP) to explore the evolution of microstructure, thermal transitions, viscoelastic properties, and local oil diffusion – an approach not previously applied to wax-based oleogels. Candelilla wax formed a dense homogenous network with small crystals and beeswax had longer needle-like aggregated structures. Both candelilla and beeswax showed one crystallization peak in DSC and a sharp increase in storage modulus during rheo-microscopy explained by their network structure. Rice bran wax had a mixture of larger spherulite structures and smaller crystals. Two distinct crystallization events were observed in DSC and rheo-microscopy for rice bran wax corresponding to the formation of large spherulites and subsequently smaller interspersed crystals. FRAP showed that candelilla wax with its dense homogenous structure had the largest retardation rate independently of observation region. The diffusion in the crystal region was fastest in the rice bran wax which indicates a loosely packed crystal structure in the spherulites

The sodium consumption in many countries is too high, which results in increased risk for hypertension, cardiovascular diseases, stroke and premature death. Inhomogeneous sodium distribution using layering is a viable way to reduce sodium in bread that normally contains a lot of sodium. Prevention of sodium migration during production and storage is important for the function of this approach. Furthermore, the distribution of sodium between starch and gluten influences their properties. The spatial distribution of sodium was investigated at high resolution using combinations of X-ray fluorescence microscopy (XFM), scanning transmission X-ray microscopy (STXM), light microscopy (LM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and image analysis. Reference breads and layered bread samples were baked with one salt-free layer and one layer containing 3.6 wt% sodium chloride salt. The obtained results showed that the concentration of sodium is higher in the starch phase than in the glutenphase and that sodiummigrates across the layer interface from the salt-containing to the salt-free layer. The ratios betweenthe sodium concentration in the starch and gluten phases were dependent on the sodium concentration across the interfaces. Furthermore, magnesium and phosphor signals in bread yeast cells were observed using XFM.

We examine the influence of surface charge on the percolation, gel-point and phase behavior of cellulose nanocrystal (CNC) suspensions in relation to their nonlinear rheological material response. Desulfation decreases CNC surface charge density which leads to an increase in attractive forces between CNCs. Therefore, by considering sulfated and desulfated CNC suspensions, we are comparing CNC systems that differ in their percolation and gel-point concentrations relative to their phase transition concentrations. The results show that independently of whether the gel-point (linear viscoelasticity, LVE) occurs at the biphasic - liquid crystalline transition (sulfated CNC) or at the isotropic - quasi-biphasic transition (desulfated CNC), the nonlinear behavior appears to mark the existence of a weakly percolated network at lower concentrations. Above this percolation threshold, nonlinear material parameters are sensitive to the phase and gelation behavior as determined in static (phase) and LVE conditions (gel-point). However, the change in material response in nonlinear conditions can occur at higher concentrations than identified through polarized optical microscopy, suggesting that the nonlinear deformations could distort the suspensions microstructure such that for example a liquid crystalline phase (static) suspension could show microstructural dynamics similar to a biphasic system.

We have studied nanorheological properties (viscosity and shear moduli) of aqueous xanthan solutions, in the oscillation frequency range up to 10 kHz by using magnetic particles that undergo Brownian relaxation and frequency dependent AC susceptibility (ACS). We used two magnetic nanoparticle (MNP) systems with different mean particle sizes of 80 nm and 100 nm. The determined viscosity and shear modulus of the diluted xanthan solutions from the ACS measurement of the two particle systems agree with traditional oscillatory rheological measurements. However, there is a particle size dependency that could be explained by comparing particles sizes with the xanthan microstructure

Ultra-high temperature (UHT) treatment of milk forms a deposit or fouling in the processing equipment that is mineral-based with an enclosed protein network. This study addresses the fundamental mechanisms that control the removal of this deposit. For this purpose, the structural and compositional changes during the cleaning process have been studied. The structure analysis was performed with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) on samples that were quenched at different stages of the cleaning process. It was found for acid cleaning that the mineral content is rapidly decreasing in the fouling layer as the cleaning continues, but there is still an intact protein structure with the similar thickness as the original fouling. For alkali cleaning, part of the protein structure was subsequently removed from the outside towards the stain-less steel as a function of time, while the mineral structure was mostly remaining. The break-up of the organic network structure, which likely involves depolymerization of protein aggregates, were found to control the cleaning efficiency. The weakening of the protein network facilitates the removal of the UHT fouling layer during the acid cleaning step and allow for an efficient cleaning cycle. The chemical reactions that occur within the fouling layer between the hydroxyl ions and the protein network was modeled according to a depolymerization reaction and a mechanistic model of the cleaning process is presented. © 2019

The use of calcium-alginate gels as carriers of food and pharmaceutical compounds is of great interest due the versatile properties of such systems. In this work, we investigated the influence of sugars (glucose:fructose) as co-solutes (15–60% (wt)) on the physico-chemical properties of calcium-alginate gel particles. Sugar concentrations above 15% (wt) reduced extensibility of alginate molecules, as shown by intrinsic viscosity measurements, and lead to a more open or less connected gel network with aggregated alginate strands. Furthermore, it is shown for the first time that sugar impacted swelling-deswelling ability of calcium alginate gels under simulated gastric (pH 1.2) and intestinal (pH 6.6) conditions. Release of sugar from calcium alginate gels with 15% (wt) and 30% (wt) sugar was close to Fickian diffusion mechanism, in both simulated gastric and intestinal fluid, with diffusion coefficient close to that previously reported for calcium-alginate gels with lower sugar contents. However, release from 60% (wt) gels in gastric fluid was slower than for 15 and 30% (wt) and, there was a drastic shrinkage of the gels under acid conditions. In intestinal fluid 60% (wt) gels showed slower release than gels with lower sugar content, this was hypothesised to be due to the lower surface area of these gels. Understanding the structure-function relationship of these gels is key to the successful design of delivery systems for food and biotechnological applications.

The use of calcium-alginate gels as carriers of food and pharmaceutical compounds is of great interest due the versatile properties of such systems. In this work, we investigated the influence of sugars (glucose:fructose) as co-solutes (15–60% (wt)) on the physico-chemical properties of calcium-alginate gel particles. Sugar concentrations above 15% (wt) reduced extensibility of alginate molecules, as shown by intrinsic viscosity measurements, and lead to a more open or less connected gel network with aggregated alginate strands. Furthermore, it is shown for the first time that sugar impacted swelling-deswelling ability of calcium alginate gels under simulated gastric (pH 1.2) and intestinal (pH 6.6) conditions. Release of sugar from calcium alginate gels with 15% (wt) and 30% (wt) sugar was close to Fickian diffusion mechanism, in both simulated gastric and intestinal fluid, with diffusion coefficient close to that previously reported for calcium-alginate gels with lower sugar contents. However, release from 60% (wt) gels in gastric fluid was slower than for 15 and 30% (wt) and, there was a drastic shrinkage of the gels under acid conditions. In intestinal fluid 60% (wt) gels showed slower release than gels with lower sugar content, this was hypothesised to be due to the lower surface area of these gels. Understanding the structure-function relationship of these gels is key to the successful design of delivery systems for food and biotechnological applications.