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Lindman, Björn
Publications (10 of 23) Show all publications
Singh, P., Magalhaes, S., Alves, L., Antunes, F., Miguel, M., Lindman, B. & Medronho, B. (2019). Cellulose-based edible films for probiotic entrapment. Food Hydrocolloids, 88, 68-74
Open this publication in new window or tab >>Cellulose-based edible films for probiotic entrapment
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2019 (English)In: Food Hydrocolloids, ISSN 0268-005X, E-ISSN 1873-7137, Vol. 88, p. 68-74Article in journal (Refereed) Published
Abstract [en]

Encapsulation with edible films is a promising approach that may solve the disadvantages associated with the use of bioactive compounds as food additives. This is particularly relevant in the case of probiotics, since their stability in food matrices and in the gastrointestinal tract may be rather poor. Therefore, new cellulose-based edible films have been successfully developed and characterized. Sodium carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC) were used for the film preparation and cross-linked with citric acid (CA) under reasonably mild conditions. Model probiotic bacteria (Lactobacillus rhamnosus GG) were incorporated in the films either during the film formation and casting or after the film synthesis, via bacteria diffusion and adsorption. The later approach could efficiently entrap and preserve viable bacteria. The mechanical properties and swelling ability could be tuned by varying the HEC/CMC ratio and the amount of CA. Moreover, the surface area and total pore volume of the films considerably decreased after cross-linking. Overall, these novel films are regarded as promising inexpensive and friendly matrices for food protection and packaging applications.

Keywords
Edible films, Citric acid, Carboxymethyl cellulose, Hydroxyethyl cellulose, Probiotic bacteria
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-35038 (URN)10.1016/j.foodhyd.2018.08.057 (DOI)000448801400008 ()2-s2.0-85054183913 (Scopus ID)
Available from: 2018-12-04 Created: 2018-12-04 Last updated: 2019-01-17Bibliographically approved
Costa, C., Mira, I., Benjamins, J.-W., Lindman, B., Edlund, H. & Norgren, M. (2019). Interfacial activity and emulsion stabilization of dissolved cellulose. Journal of Molecular Liquids, 292, Article ID 111325.
Open this publication in new window or tab >>Interfacial activity and emulsion stabilization of dissolved cellulose
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2019 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 292, article id 111325Article in journal (Refereed) Published
Abstract [en]

Some aspects of the interfacial behavior of cellulose dissolved in an aqueous solvent were investigated. Cellulose was found to significantly decrease the interfacial tension (IFT) between paraffin oil and 85 wt% phosphoric acid aqueous solutions. This decrease was similar in magnitude to that displayed by non-ionic cellulose derivatives. Cellulose's interfacial activity indicated a significant amphiphilic character and that the interfacial activity of cellulose derivatives is not only related to the derivatization but inherent in the cellulose backbone. This finding suggests that cellulose would have the ability of stabilizing dispersions, like oil-in-water emulsions in a similar way as a large number of cellulose derivatives. In its molecularly dissolved state, cellulose proved to be able to stabilize emulsions of paraffin in the polar solvent on a short-term. However, long-term stability against drop-coalescence was possible to achieve by a slight change in the amphiphilicity of cellulose, effected by a slight increase in pH. These emulsions exhibited excellent stability against coalescence/oiling-off over a period of one year. Ageing of the cellulose solution before emulsification (resulting in molecular weight reduction) was found to favour the creation of smaller droplets. 

Keywords
Adsorption, Amphiphilicity, Cellulose molecules, Emulsions, Interfacial activity, Oil-water interface
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-36838 (URN)10.1016/j.molliq.2019.111325 (DOI)2-s2.0-85069688256 (Scopus ID)
Note

Available under a Creative Commons license https://creativecommons.org/licenses/by/4.0/

Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-13Bibliographically approved
Yang, J., Dahlström, C., Edlund, H., Lindman, B. & Norgren, M. (2019). pH-responsive cellulose–chitosan nanocomposite films with slow release of chitosan. Cellulose (London), 26(6), 3763-3776
Open this publication in new window or tab >>pH-responsive cellulose–chitosan nanocomposite films with slow release of chitosan
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2019 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, no 6, p. 3763-3776Article in journal (Refereed) Published
Abstract [en]

Cellulose–chitosan films were preparedusing a physical method in which cellulose andchitosan were separately dissolved via freeze thawingin LiOH/urea and mixed in different proportions, theresulting films being cast and regenerated in water/ethanol. X-ray diffraction and Fourier transforminfrared spectroscopy (FT-IR) spectroscopy verifiedthe composition changes in the nanocomposites due todifferent mixing ratios between the polymers. Tensilestress–strain measurements indicated that the mechan-ical performance of the cellulose–chitosan nanocom-posites slightly worsened with increasing chitosancontent compared with that of films comprisingcellulose alone. Field emission scanning electronmicroscopy revealed the spontaneous formation ofnanofibers in the films; these nanofibers were subse-quently ordered into lamellar structures. Water uptakeand microscopy analysis of film thickness changesindicated that the swelling dramatically increased atlower pH and with increasing chitosan content, thisbeing ascribed to the Gibbs–Donnan effect. Slowmaterial loss appeared at acidic pH, as indicated by aloss of weight, and quantitative FT-IR analysisconfirmed that chitosan was the main componentreleased.Asample containing 75% chitosan reached amaximum swelling ratio and weight loss of 1500%and 55 wt%, respectively, after 12 h at pH 3. Thestudy presents a novel way of preparing pH-responsivecellulose–chitosan nanocomposites with slow-releasecharacteristics using an environmentally friendlyprocedure and without any chemical reactions.

Keywords
Cellulose dissolution, Chitosan dissolution, pH responsive, Gibbs–Donnan equilibrium, Nanocomposite, Slow release
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-35778 (URN)10.1007/s10570-019-02357-5 (DOI)000464849500011 ()2-s2.0-85062686323 (Scopus ID)
Funder
Swedish Research Council Formas, 942-2015-251
Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2019-09-03Bibliographically approved
Singh, P., Medronho, B., Valente, A. J. M., Miguel, M. G. & Lindman, B. (2018). Exploring the prebiotic effect of cyclodextrins on probiotic bacteria entrapped in carboxymetyl cellulose-chitosan particles. Colloids and Surfaces B: Biointerfaces, 168(August 2018), 156-162
Open this publication in new window or tab >>Exploring the prebiotic effect of cyclodextrins on probiotic bacteria entrapped in carboxymetyl cellulose-chitosan particles
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2018 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 168, no August 2018, p. 156-162Article in journal (Refereed) Published
Abstract [en]

In this work the prebiotic effect of different cyclodextrins, CDs, on the viability of model probiotic bacteria (Lactobacillus rhamnosus GG) encapsulated in carboxymethyl cellulose-chitosan (CMC-Cht) hybrid particles was studied. All the CDs tested were observed to considerably improve the viability (quantitatively like common prebiotics, such as corn starch) and encapsulation efficiency when compared to the CD-free particles, as inferred by plate counting method and fluorescence microscopy. The SEM data suggests that the morphology of the particles, the roughness of the surface and porosity, are dependent on the type of CD and may reflect different interactions between the CDs and the matrix components. The aging and stability of the samples with and without β-CD were further evaluated. Remarkably, the viability count of the CD-doped samples was still reasonably high after one month storage at room temperature with acceptable values for practical uses. Moreover, when the CMC-Cht particles were exposed to in vitro simulated digestion fluids, the cell survival was much enhanced when the particles contained β-CD. 

Keywords
Carboxylmethyl cellulose, Chitosan, Cyclodextrin, Prebiotic, Probiotic
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32764 (URN)10.1016/j.colsurfb.2017.12.014 (DOI)000443630200021 ()29307721 (PubMedID)2-s2.0-85039897467 (Scopus ID)
Available from: 2018-01-30 Created: 2018-01-30 Last updated: 2019-03-15Bibliographically approved
Cuomo, F., Cofelice, M., Venditti, F., Ceglie, A., Miguel, M., Lindman, B. & Lopez, F. (2018). In-vitro digestion of curcumin loaded chitosan-coated liposomes. Colloids and Surfaces B: Biointerfaces, 168, 29-34
Open this publication in new window or tab >>In-vitro digestion of curcumin loaded chitosan-coated liposomes
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2018 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 168, p. 29-34Article in journal (Refereed) Published
Abstract [en]

Liposomes are considered a major route for encapsulation of hydrophilic and hydrophobic molecules. Chitosan coated liposomes could represent an alternative way as a carrier for delivery of drugs in human body. In this study the preparation and applicability of chitosan-coated liposomes containing curcumin as well as curcumin loaded anionic liposomes were evaluated. The applicability of the carriers was tested by means of an in vitro digestion procedure allowing for measurement of the bioaccessibility of ingested curcumin. Values of diameter, polydispersity index and surface charge for curcumin loaded anionic liposomes obtained through dynamic light scattering and zeta-potential measurements were 129 nm, 0.095 and -49 mV, respectively. After chitosan-coating, diameter and polydispersity index remain unvaried while the surface charge gets positive. Slightly higher curcumin concentrations were found after the mouth and the stomach digestion phases when curcumin was loaded in anionic liposomes. On the contrary, after the intestinal phase, a higher percentage of curcumin was found when chitosan-coated liposomes were used as carrier, both in the raw digesta and in the bile salt micellar phase. It was shown that the presence of a positively charged surface allows a better absorption of curcumin in the small intestine phase, which increases the overall curcumin bioavailability. The mechanism behind these results can be understood from the composition of different environments generated by the digestive fluids that differently interact with anionic or cationic surfaces. 

Keywords
Chitosan, Coated-liposomes, Curcumin, Digestion phase, Bioavailability
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34536 (URN)10.1016/j.colsurfb.2017.11.047 (DOI)000443630200005 ()29183647 (PubMedID)2-s2.0-85034837484 (Scopus ID)
Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2019-03-15Bibliographically approved
Medronho, B., Filipe, A., Costa, C., Romano, A., Lindman, B., Edlund, H. & Norgren, M. (2018). Microrheology of novel cellulose stabilized oil-in-water emulsions. Journal of Colloid and Interface Science, 531(1 December 2018), 225-232
Open this publication in new window or tab >>Microrheology of novel cellulose stabilized oil-in-water emulsions
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2018 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 531, no 1 December 2018, p. 225-232Article in journal (Refereed) Published
Abstract [en]

Diffusing wave spectroscopy (DWS) is a powerful optical technique suitable to investigate turbid samples in a nondestructive and reproducible way, providing information on the static and dynamic properties of the system. This includes the relative displacement of emulsion droplets over time and changes in the viscoelastic properties. Here, novel and promising cellulose-based oil-in-water (O/W) emulsions were prepared and studied, for the first time, by DWS. Cellulose plays the role of a novel eco-friendly emulsifying agent. The hydrolysis time of cellulose was observed to affect the average size of the emulsion droplets and their stability; the longer the hydrolysis time, the more dispersed and stable the emulsions were found to be. Additionally, a good complementarity between the microrheology (DWS) and macrorheology (mechanical rheometer) data was found. Our work suggests that DWS is a highly attractive method to investigate the stability, aging and microrheology properties of cellulose-based emulsions, providing valuable insights on their microstructure. This technique is thus highly appealing for the characterization and design of novel emulsion formulations.

Keywords
Diffusing wave spectroscopy, Cellulose, Emulsions, Microrheology
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34407 (URN)10.1016/j.jcis.2018.07.043 (DOI)000444067300025 ()30032009 (PubMedID)2-s2.0-85050164802 (Scopus ID)
Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2018-09-28
Alves, L., Medronho, B., Filipe, A., Antunes, F. E., Lindman, B., Topgaard, D., . . . Talmon, Y. (2018). New Insights on the Role of Urea on the Dissolution and Thermally-Induced Gelation of Cellulose in Aqueous Alkali. GELS, 4(4), Article ID 87.
Open this publication in new window or tab >>New Insights on the Role of Urea on the Dissolution and Thermally-Induced Gelation of Cellulose in Aqueous Alkali
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2018 (English)In: GELS, ISSN 2310-2861, Vol. 4, no 4, article id 87Article in journal (Refereed) Published
Abstract [en]

The gelation of cellulose in alkali solutions is quite relevant, but still a poorly understood process. Moreover, the role of certain additives, such as urea, is not consensual among the community. Therefore, in this work, an unusual set of characterization methods for cellulose solutions, such as cryo-transmission electronic microscopy (cryo-TEM), polarization transfer solid-state nuclear magnetic resonance (PTssNMR) and diffusion wave spectroscopy (DWS) were employed to study the role of urea on the dissolution and gelation processes of cellulose in aqueous alkali. Cryo-TEM reveals that the addition of urea generally reduces the presence of undissolved cellulose fibrils in solution. These results are consistent with PTssNMR data, which show the reduction and in some cases the absence of crystalline portions of cellulose in solution, suggesting a pronounced positive effect of the urea on the dissolution efficiency of cellulose. Both conventional mechanical macrorheology and microrheology (DWS) indicate a significant delay of gelation induced by urea, being absent until ca. 60 degrees C for a system containing 5wt % cellulose, while a system without urea gels at a lower temperature. For higher cellulose concentrations, the samples containing urea form gels even at room temperature. It is argued that since urea facilitates cellulose dissolution, the high entanglement of the cellulose chains in solution (above the critical concentration, C*) results in a strong three-dimensional network.

Keywords
cellulose, gelation, urea, NaOH, microrheology, cryo-transmission electronic microscopy, polarization transfer solid-state NMR, hydrophobic interactions
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-36101 (URN)10.3390/gels4040087 (DOI)000461141800008 ()30674863 (PubMedID)
Available from: 2019-05-07 Created: 2019-05-07 Last updated: 2019-05-07Bibliographically approved
Alves, L., Lindman, B., Klotz, B., Böttcher, A., Haake, H.-M. & Antunes, F. E. (2018). On the rheology of mixed systems of hydrophobically modified polyacrylate microgels and surfactants: Role of the surfactant architecture. Journal of Colloid and Interface Science, 513, 489-496
Open this publication in new window or tab >>On the rheology of mixed systems of hydrophobically modified polyacrylate microgels and surfactants: Role of the surfactant architecture
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2018 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 513, p. 489-496Article in journal (Refereed) Published
Abstract [en]

Hypothesis The rheological control of suspensions is of key interest in the formulation design. A chemically cross-linked hydrophobically modified poly(acrylic acid) (HMCL-PAA), used as rheology modifier, is pH sensitive and shows swelling behavior above a critical pH due to the ionization of the acrylic acid groups. At low pH, HMCL-PAA suspensions are liquid and turbid. The binding of surfactants to HMCL-PAA, at low pH conditions, can result in significant changes on rheology and transparency of the polymeric suspensions, due to the swelling of the microgel particles. Experiments The influence of surfactants addition on the rheological properties and transparency of HMCL-PAA suspensions was determined. A systematic study was performed using different types of surfactants (ionic, non-ionic and zwitterionic). Findings The gelation efficiency of HMCL-PAA suspensions at low pH is strongly dependent on surfactant architecture: ionic surfactants are found to be much more efficient than non-ionic or zwitterionic surfactants. Ionic surfactants lead to a liquid-to-gel transition accompanied by an increase of transparency of the suspensions. Among the ionic surfactants, anionics show stronger interactions with the polymer. Also the surfactant hydrophobicity is relevant; the more hydrophobic the surfactant, the stronger is the binding to the polymer and thus the larger the particle swelling. 

Keywords
Crosslinked polymer, Gelation, Hydrophobic association, Poly(acrylic acid) derivative, Polymer/surfactant association, Surfactant binding
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32714 (URN)10.1016/j.jcis.2017.11.047 (DOI)000428834900053 ()29179089 (PubMedID)2-s2.0-85034853825 (Scopus ID)
Available from: 2018-01-19 Created: 2018-01-19 Last updated: 2018-05-08Bibliographically approved
Singh, P., Medronho, B., dos Santos, T., Nunes-Correia, I., Granja, P., Miguel, M. G. & Lindman, B. (2018). On the viability, cytotoxicity and stability of probiotic bacteria entrapped in cellulose-based particles. Food Hydrocolloids, 82, 457-465
Open this publication in new window or tab >>On the viability, cytotoxicity and stability of probiotic bacteria entrapped in cellulose-based particles
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2018 (English)In: Food Hydrocolloids, ISSN 0268-005X, E-ISSN 1873-7137, Vol. 82, p. 457-465Article in journal (Refereed) Published
Abstract [en]

Probiotics are increasingly gaining popularity in vast food applications due to their recognized health benefits to the host. However, their passage through the gastrointestinal (GI) tract is not smooth and a significant number of physiological barriers (e.g. low pH, bile salts, enzymes, peristaltic movements, etc.) may considerably affect their viability. The entrapment of probiotics in protective matrices, such as hydrogel particles, is a feasible approach to minimize cell death. Therefore, in this work, novel cellulose/chitosan-based particles have been developed to entrap model probiotic Lactobacillus rhamnosus GG. The particle aging, storing and stability was studied at different temperatures and in simulated GI fluids with and without cross-linking agents or protein and lipid additives. Moreover, the effect of the particles on a model intestinal cell line was evaluated. The formulations containing casein displayed the best bacterial survival/culturability when exposed to the GI fluids. Overall, the storage and viability of the probiotics were observed to be improved in the different biopolymer-based systems, generally presenting a low toxicity profile to the cell line. Thus, the particles, which were based on carboxymethyl cellulose and chitosan, may be regarded as interesting matrices for probiotic encapsulation and delivery in food products. 

Keywords
Probiotic, Carboxymethyl cellulose, Chitosan, Genipin, Casein, Particles
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-33733 (URN)10.1016/j.foodhyd.2018.04.027 (DOI)000432774000050 ()2-s2.0-85047479547 (Scopus ID)
Available from: 2018-06-10 Created: 2018-06-10 Last updated: 2018-07-04Bibliographically approved
Singh, P., Medronho, B., Alves, L., da Silva, G. J., Miguel, M. G. & Lindman, B. (2017). Development of carboxymethyl cellulose-chitosan hybrid micro- and macroparticles for encapsulation of probiotic bacteria. Carbohydrate Polymers, 175, 87-95
Open this publication in new window or tab >>Development of carboxymethyl cellulose-chitosan hybrid micro- and macroparticles for encapsulation of probiotic bacteria
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2017 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 175, p. 87-95Article in journal (Refereed) Published
Abstract [en]

Novel carboxymethyl cellulose-chitosan (CMC-Cht) hybrid micro- and macroparticles were successfully prepared in aqueous media either by drop-wise addition or via nozzle-spray methods. The systems were either physically or chemically crosslinked using genipin as the reticulation agent. The macroparticles (ca. 2 mm) formed are found to be essentially of the core-shell type, while the microparticles (ca. 5 μm) are apparently homogeneous. The crosslinked particles are robust, thermally resistant and less sensitive to pH changes. On the other hand, the physical systems are pH sensitive presenting a remarkable swelling at pH 7.4, while little swelling is observed at pH 2.4. Furthermore, model probiotic bacteria (Lactobacillus rhamnosus GG) was for the first time successfully encapsulated in the CMC-Cht based particles with acceptable viability count. Overall, the systems developed are highly promising for probiotic encapsulation and potential delivery in the intestinal tract with the purpose of modulating gut microbiota and improving human health.

Keywords
Carboxymethyl cellulose, Chitosan, Encapsulation, Genipin, Micro/macroparticles, Probiotic
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32183 (URN)10.1016/j.carbpol.2017.06.119 (DOI)000411112500010 ()28917929 (PubMedID)2-s2.0-85026403113 (Scopus ID)
Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2017-12-12Bibliographically approved
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