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  • 1.
    Andersson, I. M.
    et al.
    Lund University, Sweden.
    Glantz, M.
    Lund University, Sweden.
    Alexander, M.
    Arla Foods Ingredients Group P/S, Denmark.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Paulsson, M.
    Lund University, Sweden.
    Bergenståhl, B.
    Lund University, Sweden.
    Impact of surface properties on morphology of spray-dried milk serum protein/lactose systems2018In: International Dairy Journal, ISSN 0958-6946, E-ISSN 1879-0143, Vol. 85, p. 86-95Article in journal (Refereed)
    Abstract [en]

    This study investigated milk serum protein concentrate/lactose systems with varying ratios and how the morphology of the spray-dried particles of these systems could be described by the surface properties of the feed as well as the protein surface coverage of the particles. An extrapolation of the surface pressure of the feed to 0.3 s, the approximate time for molecular diffusion in an atomised droplet in the spray-dryer, showed a relationship with the particle morphology. At low protein concentrations (<1%), the particles were almost totally smooth. At higher protein concentrations (≥1%), the particles became dented and ridged, and these tended to become deeper and thicker as the protein concentration increased. It is suggested that the surface pressure of the feed at low protein concentrations is the most prominent surface property, whereas the modulus of elasticity seems to be the most prominent surface property for particle surface deformation at higher protein concentrations.

  • 2.
    Andersson, I. M.
    et al.
    Lund University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Alexander, M.
    Arla Foods Ingredients Group P/S, Denmark.
    Hellström, N.
    Lund University, Sweden.
    Glantz, Maria
    Lund University, Sweden.
    Paulsson, M.
    Lund University, Sweden.
    Bergenståhl, Björn
    Lund University, Sweden.
    Impact of protein surface coverage and layer thickness on rehydration characteristics of milk serum protein/lactose powder particles2019In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 561, p. 395-404Article in journal (Refereed)
    Abstract [en]

    Spray-dried powders were produced from milk serum protein concentrate and lactose in varying ratios, and the rehydration characteristics of the powders were evaluated. The dissolution rate was estimated with a flow-cell based technique, and the external and internal distribution of the powder components were evaluated with X-ray photoelectron spectroscopy and confocal Raman microscopy, respectively. The surface of the powder particles is more or less covered by a thin protein layer. A phase segregation between protein and lactose is observed in the interior of the particle resulting in a protein rich layer in the vicinity of the surface. However, the protein layer in the vicinity of the particle surface tends to become thinner as the bulk protein concentration increases in the powders (from 10 to 60% w/w). The time for the spontaneous imbibition to occur show a linear correlation with the protein surface coverage. The dissolution rate of powders containing 0.1% w/w protein is around 60 times faster than for a powder containing 1% w/w protein but the dissolution rate of powders containing 1% and 100% w/w differ only by a factor of 2. Thus, it is suggested that the outer protein layer becomes denser at the interface as the protein content increases in the powders, thereby causing poorer rehydration characteristics of the powders (especially for low protein concentrations 0.1–1% w/w). This insight has relevance for the formulation of whey protein powders with improved rehydration characteristics. © 2018 Elsevier B.V.

  • 3.
    Badal Tejedor, Maria
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Nordgren, Niklas
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Schuleit, M
    Rutland, Mark W.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Tablet mechanics depend on nano and micro scale adhesion, lubrication and structure2015In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 486, no 1-2, p. 315-323Article in journal (Refereed)
    Abstract [en]

    Tablets are the most convenient form for drug administration. However, despite the ease of manufacturing problems such as powder adhesion occur during the production process. This study presents surface and structural characterization of tablets formulated with commonly used excipients (microcrystalline cellulose (MCC), lactose, mannitol, magnesium (Mg) stearate) pressed under different compaction conditions. Tablet surface analyses were performed with scanning electron microscopy (SEM), profilometry and atomic force microscopy (AFM). The mechanical properties of the tablets were evaluated with a tablet hardness test. Local adhesion detected by AFM decreased when Mg stearate was present in the formulation. Moreover, the tablet strength of plastically deformable excipients such as MCC was significantly decreased after addition of Mg stearate. Combined these facts indicate that Mg stearate affects the particle-particle bonding and thus elastic recovery. The MCC excipient also displayed the highest hardness which is characteristic for a highly cohesive material. This is discussed in the view of the relatively high adhesion found between MCC and a hydrophilic probe at the nanoscale using AFM. In contrast, the tablet strength of brittle materials like lactose and mannitol is unaffected by Mg stearate. Thus fracture occurs within the excipient particles and not at particle boundaries, creating new surfaces not previously exposed to Mg stearate. Such uncoated surfaces may well promote adhesive interactions with tools during manufacture.

  • 4.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Nordgren, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Schuleit, Michael
    Novartis Pharma AG, Switzerland.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    AFM Colloidal Probe Measurements Implicate Capillary Condensation in Punch-Particle Surface Interactions during Tableting2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 46, p. 13180-13188Article in journal (Refereed)
    Abstract [en]

    Adhesion of the powders to the punches is a common issue during tableting. This phenomenon is known as sticking and affects the quality of the manufactured tablets. Defective tablets increase the cost of the manufacturing process. Thus, the ability to predict the tableting performance of the formulation blend before the process is scaled-up is important. The adhesive propensity of the powder to the tableting tools is mostly governed by the surface-surface adhesive interactions. Atomic force microscopy (AFM) colloidal probe is a surface characterization technique that allows the measurement of the adhesive interactions between two materials of interest. In this study, AFM steel colloidal probe measurements were performed on ibuprofen, MCC (microcrystalline cellulose), α-lactose monohydrate, and spray-dried lactose particles as an approach to modeling the punch-particle surface interactions during tableting. The excipients (lactose and MCC) showed constant, small, attractive, and adhesive forces toward the steel surface after a repeated number of contacts. In comparison, ibuprofen displayed a much larger attractive and adhesive interaction increasing over time both in magnitude and in jump-in/jump-out separation distance. The type of interaction acting on the excipient-steel interface can be related to a van der Waals force, which is relatively weak and short-ranged. By contrast, the ibuprofen-steel interaction is described by a capillary force profile. Even though ibuprofen is not highly hydrophilic, the relatively smooth surfaces of the crystals allow "contact flooding" upon contact with the steel probe. Capillary forces increase because of the "harvesting" of moisture - due to the fast condensation kinetics - leaving a residual condensate that contributes to increase the interaction force after each consecutive contact. Local asperity contacts on the more hydrophilic surface of the excipients prevent the flooding of the contact zone, and there is no such adhesive effect under the same ambient conditions. The markedly different behavior detected by force measurements clearly shows the sticky and nonsticky propensity of the materials and allows a mechanistic description.

  • 5.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Nordgren, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Schuleit, Michael
    Novartis Pharma AG, Switzerland.
    Pazesh, Samaneh
    Uppsala University, Sweden.
    Alderborn, Göran
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Determination of interfacial amorphicity in functional powders2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 4, p. 920-926Article in journal (Refereed)
    Abstract [en]

    The nature of the surfaces of particles of pharmaceutical ingredients, food powders, and polymers is a determining factor for their performance in for example tableting, powder handling, or mixing. Changes on the surface structure of the material will impact the flow properties, dissolution rate, and tabletability of the powder blend. For crystalline materials, surface amorphization is a phenomenon which is known to impact performance. Since it is important to measure and control the level of amorphicity, several characterization techniques are available to determine the bulk amorphous content of a processed material. The possibility of characterizing the degree of amorphicity at the surface, for example by studying the mechanical properties of the particles' surface at the nanoscale, is currently only offered by atomic force microscopy (AFM). The AFM PeakForce QNM technique has been used to measure the variation in energy dissipation (eV) at the surface of the particles which sheds light on the mechanical changes occurring as a result of amorphization or recrystallization events. Two novel approaches for the characterization of amorphicity are presented here. First, since particles are heterogeneous, we present a methodology to present the results of extensive QNM analysis of multiple particles in a coherent and easily interpreted manner, by studying cumulative distributions of dissipation data with respect to a threshold value which can be used to distinguish the crystalline and amorphous states. To exemplify the approach, which is generally applicable to any material, reference materials of purely crystalline α-lactose monohydrate and completely amorphous spray dried lactose particles were compared to a partially amorphized α-lactose monohydrate sample. Dissipation data are compared to evaluations of the lactose samples with conventional AFM and SEM showing significant topographical differences. Finally, the recrystallization of the surface amorphous regions in response to humidity was followed by studying the dissipation response of a well-defined surface region over time, which confirms both that dissipation measurement is a useful measure of surface amorphicity and that significant recrystallization occurs at the surface in response to humidity.

  • 6.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Pazesh, Samaneh
    Uppsala University, Sweden.
    Nordgren, Niclas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Schuleit, Micheal
    Novartis Pharma AG, Switzerland.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. KTH Royal Institute of Technology, Sweden.
    Alderborn, Göran
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Milling induced amorphisation and recrystallization of α-lactose monohydrate2018In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 537, no 1-2, p. 140-147Article in journal (Refereed)
    Abstract [en]

    Preprocessing of pharmaceutical powders is a common procedure to condition the materials for a better manufacturing performance. However, such operations may induce undesired material properties modifications when conditioning particle size through milling, for example. Modification of both surface and bulk material structure will change the material properties, thus affecting the processability of the powder. Hence it is essential to control the material transformations that occur during milling. Topographical and mechanical changes in surface properties can be a preliminary indication of further material transformations. Therefore a surface evaluation of the α-lactose monohydrate after short and prolonged milling times has been performed. Unprocessed α-lactose monohydrate and spray dried lactose were evaluated in parallel to the milled samples as reference examples of the crystalline and amorphous lactose structure. Morphological differences between unprocessed α-lactose, 1 h and 20 h milled lactose and spray dried lactose were detected from SEM and AFM images. Additionally, AFM was used to simultaneously characterize particle surface amorphicity by measuring energy dissipation. Extensive surface amorphicity was detected after 1 h of milling while prolonged milling times showed only a moderate particle surface amorphisation. Bulk material characterization performed with DSC indicated a partial amorphicity for the 1 h milled lactose and a fully amorphous thermal profile for the 20 h milled lactose. The temperature profiles however, were shifted somewhat in the comparison to the amorphous reference, particularly after extended milling, suggesting a different amorphous state compared to the spray-dried material. Water loss during milling was measured with TGA, showing lower water content for the lactose amorphized through milling compared to spray dried amorphous lactose. The combined results suggest a surface-bulk propagation of the amorphicity during milling in combination with a different amorphous structural conformation to that of the amorphous spray dried lactose. The hardened surface may be due to either surface crystallization of lactose or to formation of a low-water glass transition.

  • 7.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Västberg, Amanda
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Umerska, Anita
    Université Bretagne Loire, France.
    Bysell, Helena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Eriksson, Jonny
    Uppsala University, Sweden.
    Edwards, Katarina
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Freeze-dried and re-hydrated liquid crystalline nanoparticles stabilized with disaccharides for drug-delivery of the plectasin derivative AP114 antimicrobial peptide2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 522, p. 126-135Article in journal (Refereed)
    Abstract [en]

    Liquid crystalline nanoparticles (LCNPs), e.g. cubosomes and hexosomes, are receiving more and more attraction as drug delivery vehicles. Dry powder formulation that forms LCNPs upon hydration can be advantageous to make new routes of administration accessible. In this work, we investigate use of three disaccharides (lactose, trehalose and sucrose) as protective matrices for glycerol monooleate based LCNP forming powders produced by freeze-drying. Phase behavior, particle size and size distributions at the different preparation steps were monitored by small angle x-ray scattering (SAXS) and dynamic light scattering (DLS). Particle appearance was imaged by cryogenic transmission electron microscopy (cryo-TEM). Moreover, the therapeutic relevant antimicrobial peptide AP114 (plectasin derivative) was incorporated in the formulations. Peptide encapsulation and release as well as in vitro antibacterial effect were investigated. Results showed that all freeze-dried powders did form particles with liquid crystalline structure upon hydration. However, a phase transition from the bicontinuous cubic Pn3m to the reversed hexagonal was observed, as a consequence of sugar addition and the freeze-drying procedure. Data indicates that trehalose is the preferred choice of lyo-protectant in order to maintain a mono-modal particle size distribution. In addition, antimicrobial activity of AP114-containing formulations was found to be highest for the formulation containing trehalose. The release kinetics of AP114 from the nanoparticles was strongly affected by the dimensions of the hexagonal phase. Larger dimension of the hexagonal phase, significantly improved the release of AP114 and antimicrobial activity of the formulation.

  • 8.
    Both, E M
    et al.
    Wageningen University and Research, The Netherlands.
    Nuzzo, Marine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Boom, R M
    Wageningen University and Research, The Netherlands.
    Schutyser, M A I
    Wageningen University and Research, The Netherlands.
    Morphology development during single droplet drying of mixed component formulations and milk2018In: Food Research International, ISSN 0963-9969, E-ISSN 1873-7145, Vol. 109, p. 448-454, article id S0963-9969(18)30328-4Article in journal (Refereed)
    Abstract [en]

    We report on the influence of selected components and their mixtures on the development of the morphology during drying of single droplets and extend the results to the morphology of whole milk powder particles. Sessile single droplet drying and acoustic levitation methods were employed to study single droplet drying. The influence of carbohydrates (lactose and maltodextrin DE12) and proteins (micellar casein or whey protein) on morphology development is very different, since upon concentration protein systems will jam and undergo a colloidal glass transition, whereas carbohydrate systems will gradually increase in viscosity as a consequence of the concentration. Whey protein gives relatively rigid shells due to jamming of the "hard sphere" proteins, while casein micelles behave as "soft spheres" that can deform after jamming, which gives flexibility to the shell during drying. The influence of the carbohydrates on the final morphology was found much larger than the influence of the proteins. Caseins influenced morphology only in mixtures with lactose at higher concentrations due to its high voluminosity. Similar observations were done for whole milk, where fat appeared to have no influence. With maltodextrin the influence of the casein was again observed in the shape and smoothness of wrinkles. Both sessile and levitated droplet drying methods provide a similar and consistent view on morphology development.

  • 9. Dahlberg, Carina
    et al.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Schuleit, Michael
    Furó, Istvan
    Polymer-drug interactions and wetting of solid dispersions2010In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 39, no 1-3, p. 125-133Article in journal (Refereed)
    Abstract [en]

    We demonstrate the ability of drugs to influence the wetting of solid dispersion tablets in unexpected ways. Five model drugs of different water solubility and ability to interact with the involved polymers were incorporated in hydrophilic polymer matrices, made of either hydroxypropyl methylcellulose (HPMC) or polyvinyl pyrrolidone (PVP). The physical mixtures of all combinations of drug and polymer presented Surface hydrophobicities, as measured by the equilibrium advancing contact angle of water, which are expected for materials that do not influence the interactions of each other with water. However, the solid dispersions containing HPMC deviated from this regular behaviour and displayed contact angles below those of the pure compounds involved. either drug or polymer. This behaviour is explained by changed surface exposure of HPMC side groups, as a result of changes in intermolecular hydrogen bonds. In addition to water contact angle measurements, we employed NMR imaging to monitor the time course of water ingress and swelling.

  • 10. Dahlberg, Carina
    et al.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Schuleit, Michael
    Furó, Istvan
    Relationships between solid dispersion preparation process, particle size and drug release - An NMR and NMR microimaging study2010In: European journal of pharmaceutics and biopharmaceutics, ISSN 0939-6411, E-ISSN 1873-3441, Vol. 76, no 2, p. 311-319Article in journal (Refereed)
    Abstract [en]

    Solid dispersion tablets prepared by either spray drying or rotoevaporation and exhibiting different grain and pore sizes were investigated under the process of hydration-swelling-gelation. H-2 and H-1 NMR microimaging experiments were used to selectively follow water penetration and polymer mobilization kinetics, respectively, while the drug release kinetics was followed by H-1 NMR spectroscopy. The obtained data, in combination with morphological information by scanning electron microscopy (SEM), reveal a complex process that ultimately leads to release of the drug into the aqueous phase. We find that the rate of water ingress has no direct influence on release kinetics, which also renders air in the tablets a secondary factor. On the other hand, drug release is directly correlated with the polymer mobilization kinetics. Water diffusion into the originally dry polymer grains determines the rate of grain swelling and the hydration within the grains varies strongly with grain size. We propose that this sets the stage for creating homogeneous gels for small grain sizes and heterogeneous gels for large grain sizes. Fast diffusion through water-rich sections of the inhomogeneous gels that exhibit a large mesh size is the factor which yields a faster drug release from tablets prepared by rotoevaporation.

  • 11. Dahlenborg, H
    et al.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Bergenståhl, B
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Effect of shell microstructure on oil migration and fat bloom development in model pralines2015In: Food Structure, ISSN 2213-3291, Vol. 5, p. 51–65-Article in journal (Refereed)
    Abstract [en]

    This study investigated the influence of shell microstructure on oil migration and fat bloom development in chocolate model systems. The microstructure of the model shells was varied by means of tempering or seeding cocoa butter and the addition of non-fat particles. Further, the impact of different storage conditions was studied. By using a set of novel analytical techniques the migration rate could be connected to the development of fat bloom at the surface. The non-seeded cocoa butter samples showed significantly higher rate of migration together with the highest rate of developed fat bloom, whereas the over-seeded cocoa butter samples showed low migration rate and low rate of fat bloom development. Addition of particles (sugar, cocoa powder and defatted cocoa powder) proved to have a significant impact on the microstructure, since these samples showed a substantially higher rate of migration and fat bloom development compared to seeded cocoa butter samples. Molecular diffusion could not explain the migration behaviour, thus, convective flow is suggested as an important contribution in addition to the molecular diffusion.

  • 12. Dahlenborg, H
    et al.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Brandner, Birgit D
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Bergenståhl, B
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Study of the porous structure of white chocolate by confocal Raman microscopy2012In: European Journal of Lipid Science and Technology, ISSN 1438-7697, E-ISSN 1438-9312, Vol. 114, no 8, p. 919-926Article in journal (Refereed)
    Abstract [en]

    Confocal Raman microscopy has been shown to be a useful technique for investigation of white chocolate surfaces. The appearance of protrusions and pores, and the distribution of fat, sucrose, and milk powder at and below the surface of white chocolate pralines were investigated using confocal Raman microscopy. Raman horizontal and depth scans showed that the protrusions and pores continue at least 10μm into the chocolate shell and that some protrusions and channels mainly consist of fat, while some consisted of a fat layer, leaving a hollow space underneath. Further, the pores and their continuing channels consisted of nothing but air. These findings indicate that the protrusions might be connected to channels where we suggest a pressure driven convective flow of liquid fat from within the chocolate matrix that, depending on temperature, moves up to the surface or goes back into the matrix, leaving an empty pore with a shell of fat at the surface, which in some cases collapse and leaves a hollow pore and channel. Therefore, these findings support that the protrusions could be connected to oil migration in chocolate and, thus, further to fat bloom development.

  • 13. Dahlenborg, Hanna
    et al.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Bergenståhl, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Kalnin, Daniel JE
    Investigation of chocolate surfaces using profilometry and low vacuum scanning electron microscopy2011In: Journal of the American Oil Chemists Society, ISSN 0003-021X, E-ISSN 1558-9331, Vol. 88, no 6, p. 773-783Article in journal (Refereed)
    Abstract [en]

    In this study we establish the use of optical non-contact profilometry combined with low vacuum scanning electron microscopy (LV SEM) for the investigation of lipid surfaces. We illustrate, by using profilometry, a methodology for investigation of chocolate surface topology as a function of time, in the same area of interest. Both qualitative and quantitative data analysis has been performed for profilometry data. Further, relating these results to LV SEM images provides complementary topological information and hence a useful toolkit for the study of the chocolate surface prior and post fat bloom formation. For the demonstration of the successful combination of these two analytical techniques, white chocolate pralines were stored at two temperature-controlled conditions (at 18 °C, and cycled between 15 and 25 °C). Surface properties were then investigated during 36 weeks of storage. The surface images and the roughness parameters indicated distinct development of surface characteristics for the two storage conditions. From the results it is suggested that some imperfections, in the form of pores or protrusions, could play a role in fat bloom development and that there may be different main mechanisms of fat migration taking place for the different storage environments. In the present work, a positive correlation of profilometry data to chocolate surface characteristics and early bloom development has been established. There are indications that early prediction of fat bloom can be possible, however further work needs to be done to quantify prediction of fat bloom.

  • 14.
    Elofsson, Ulla
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Stability of spray-dried protein-stabilized emulsions: Effects of different carbohydrate additives2003In: Food Colloids, Biopolymers and Materials / [ed] Eric Dickinson, Ton van Vliet, Royal Society of Chemistry, 2003, p. 265-274Chapter in book (Refereed)
  • 15.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Aqueous two-phase systems for microencapsulation in food applications: Chapter 152014In: Microencapsulation in the Food Industry: A Practical Implementation Guide / [ed] A Gaonkar, N Vasisht, A Kare, R Sobel, Elsevier, 2014, p. 157-169Chapter in book (Refereed)
  • 16.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Encapsulation approaches for proteins: Chapter 162008In: Delivery and Controlled Release of Bioactives in Foods and Nutraceuticals / [ed] Nissim Garti, Elsevier, 2008, p. 404-425Chapter in book (Refereed)
  • 17.
    Millqvist-Fureby, Anna
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Burns, N
    Surface activity at the air-water interface in relation to surface composition of spray-dried milk protein-stabilized emulsions1999In: Food Emulsions and Foams / [ed] Dickinson, E. & Rodriguez Patino, J.M., Royal Society of Chemistry, 1999, p. 236-245Chapter in book (Refereed)
  • 18.
    Millqvist-Fureby, Anna
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Larsson, Anders
    Mesoporous solid carrier particles in controlled delivery and release: Chapter 252014In: Microencapsulation in the Food Industry: A Practical Implementation Guide / [ed] A Gaonkar, N Vasisht, A Kare, R Sobel, Elsevier, 2014, p. 299-319Chapter in book (Refereed)
  • 19.
    Nuzzo, Marine
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. Lund University, Food Technology, Engineering and Nutrition.
    Sloth, J.
    Bergenstahl, B.
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Phase segregation in individually dried particles composed of biopolymers2015In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, no 40, p. 10946-10954Article in journal (Refereed)
    Abstract [en]

    Mixing of two biopolymers can results in phase separation due to their thermodynamically incompatibility under certain conditions. This phenomenon was first reported when the solution was allowed to equilibrate, but it has later been observed also as a consequence of drying. The challenges of this study were to observe phase segregation by confocal Raman microscopy and LV-SEM on dried film, individually dried particles, and spray dried particles. The influence of the solid content and the phase ratio (composition) of a HPMC/maltodextrin mixture on the localization of the ingredients in the individually dried particles was investigated. We observed that phase segregation of HPMC and maltodextrin is induced by solvent evaporation in film drying, single particle drying, as well as spray drying. The phase ratio is an important parameter that influences the localization of the HPMC-enriched phase and maltodextrin-enriched phase, i.e., to the particle surface, to the core, or in a more or less bicontinuous pattern. The drying time, affected by the solids content, was found to control the level of advancement of the phase segregation.

  • 20.
    Nuzzo, Marine
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Sloth, J
    Brandner, Birgit
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Bergenstahl, B
    Millqvist-Fureby, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Confocal Raman microscopy for mapping phase segregation in individually dried particles composed of lactose and macromolecules2015In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 481, p. 229-236Article in journal (Refereed)
    Abstract [en]

    The quality of powder is determined by its functionality such as dissolution, encapsulation and flowability. The functionality of powder is in turn determined by their primary properties such as morphology and composition which need to be studied. Hence morphology and surface composition has been largely investigated in spray dried powders and individually dried particles. On the contrary, there is only scarce information regarding the internal structure. With the aim of acquiring a better understanding of the localization of different ingredients in spray dried powders we have used confocal Raman microscopy to investigate the internal microstructure of individually dried particles. In this study three different macromolecules have been investigated: bovine serum albumin, hydroxypropyl methyl cellulose, and triblock co-polymer poloxamer in a lactose matrix are compared at various macromolecule to lactose ratios. The surface and internal component distribution in response to the macromolecule concentration has been established. For the first time phase segregation in particles during a short drying time range is shown. Macromolecules were enriched at the surface of the dried particles and a macromolecule depleted layer was observed below the surface. Macromolecule enriched domains were found segregated from the amorphous lactose matrix in the internal part of the particles. Confocal Raman microscopy was found to be a powerful tool for internal mapping in individually dried particles.

  • 21.
    Nuzzo, Marine
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. Lund University, Sweden.
    Sloth Overgaard, Jakob
    GEA Process Engineering AS, Denmark.
    Bergenståhl, Bjorn
    Lund University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    The morphology and internal composition of dried particles from whole milk—From single droplet to full scale drying2017In: Food Structure, ISSN 2213-3291, Vol. 13, p. 35-44Article in journal (Refereed)
    Abstract [en]

    Powder structure and functionality are expected to be closely linked to the composition and drying process. In order to understand the optimization of the quality of a powder, e.g. encapsulation efficiency, or wetting and dispersion properties, monitoring of the particle microstructure is an attractive concept. However, to study the impact of different parameters in formulation and drying process on full scale is complicated and expensive, hence, studies on smaller scale, even single particle drying, is a potentially useful complement, as long as the results are comparable. The aim of this study is to compare morphology and internal composition of whole milk particles produced at different dryer scales to assess the development of internal structure in powder formed by spray drying. Whole milk was spray dried in the single particle dryer, laboratory dryer, pilot plant dryer and full scale dryer. The morphology and composition of the particles obtained were analyzed by low vacuum-SEM, confocal Raman microscopy and X-ray photoelectron spectroscopy. Phenomena such as adsorption of surface active compounds at the particle surface and phase segregation are observed to different extent, depending on particle size and drying time. The scale of drying influences the internal microstructure and distribution of components in the particles, and to a small extent also the external morphology. These effects are proposed to be related to the drying times for different droplet sizes, although mechanical handling effects and agglomeration in the full scale dryer may also influence the final morphology of these particles, as well as the surface composition.

1 - 21 of 21
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