| 1. |
- Bernal, Ximena E., et al.
(författare)
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Empowering Latina scientists
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 363:6429, s. 825-826
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
- Fontes-Candia, Cynthia, et al.
(författare)
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Maximizing the oil content in polysaccharide-based emulsion gels for the development of tissue mimicking phantoms
- 2021
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Ingår i: Carbohydrate Polymers. - : Elsevier Ltd. - 0144-8617 .- 1879-1344. ; 256
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Tidskriftsartikel (refereegranskat)abstract
- Formulations based on agar and κ-carrageenan were investigated for the production of emulsion gels applicable as tissue mimicking phantoms. The effects of the polysaccharide matrix, the oil content and the presence of surfactants on the micro-/nanostructure, rheology, and mechanical and dielectric properties were investigated. Results showed a high capacity of the agar to stabilize oil droplets, producing gels with smaller (10−21 μm) and more uniform oil droplets. The addition of surfactants allowed increasing the oil content and reduced the gel strength and stiffness down to 57 % and 34 %, respectively. The permittivity and conductivity of the gels were reduced by increasing the oil content, especially in the agar gels (18.8 and 0.05 S/m, respectively), producing materials with dielectric properties similar to those of low-water content tissues. These results evidence the suitability of these polysaccharides to design a variety of tissue mimicking phantoms with a broad range of mechanical and dielectric properties.
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| 4. |
- Fontes-Candia, Cynthia, et al.
(författare)
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Rheological and structural characterization of carrageenan emulsion gels
- 2020
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Ingår i: Algal Research. - : Elsevier B.V.. - 2211-9264. ; 47
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Tidskriftsartikel (refereegranskat)abstract
- Carrageenan emulsion gels containing sunflower oil were prepared using three different commercial carrageenan grades (κ-C, ι-C and λ-C). The effect of the carrageenan and salt content, as well as the oil:water ratio, on the emulsion gel strength was evaluated through a response surface methodology. Moreover, the rheological properties and the micro- and nanostructure from the stronger emulsion gel formulations were investigated and compared to their analogous hydrogel formulations. Interestingly, emulsion gels formed stronger and more thermally stable networks than the hydrogels, being this effect more evident in ι-C and λ-C. The results indicate that this was mainly due to a polysaccharide concentration effect, as no evidence of interactions between the carrageenan and the oil phase was found. Consequently, the rheological behaviour of the emulsion gels was mostly determined by the type of carrageenan. The association of carrageenan molecular chains was favoured in κ-C and λ-C (due to the presence of κ-carrageenan in the latter) and promoted by the addition of KCl. In contrast, a lower degree of chain association, mostly driven by ionic cross-linking, took place in ι-C. These results evidence the relevance of the gelation mechanism on the properties of emulsion gels and provide the basis for the design of these systems for targeted applications within the food industry.
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| 5. |
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| 6. |
- Malafronte, Loredana, 1986, et al.
(författare)
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Macroalgae suspensions prepared by physical treatments: Effect of polysaccharide composition and microstructure on the rheological properties
- 2021
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X .- 1873-7137. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- The use of macroalgae in food products is growing due to their techno-functionality and nutritional properties. In this context, an increased understanding of the rheological properties which are relevant for manufacturing and texture is needed. Here we investigated the impact of thermal and mechanical treatments, including high pressure homogenisation (HPH), on the polysaccharide composition, microstructure, and rheological properties of brown algae Laminaria digitata suspensions (5 wt %). Monosaccharide analysis and immunolabeling of alginate in combination with confocal laser scanning microscopy, revealed a sequential release of different polysaccharides as result of the applied shear. Results showed that thermal treatment (70 °C 1 h) and mild shear lead to suspensions of clusters of cells and release of fucoidan and laminarin into the liquid phase, conferring shear thinning properties to the suspensions. High pressure homogenisation was able to completely break the macroalgae cells, reducing particle size and releasing other soluble polysaccharides, in particular alginate, conferring gel properties (G'>G'') to the suspensions. This study contributes to the knowledge of how to design sustainable, innovative and nutritious liquid/semiliquid food products containing macroalgae biomass.
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| 7. |
- Martinez-Sanz, Marta, et al.
(författare)
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Advanced structural characterisation of agar-based hydrogels : Rheological and small angle scattering studies
- 2020
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 236
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Tidskriftsartikel (refereegranskat)abstract
- Agar-based extracts from Gelidium sesquipedale were generated by heat and combined heat-sonication, with and without the application of alkali pre-treatment. Pre-treatment yielded extracts with greater agar contents; however, it produced partial degradation of the agar, reducing its molecular weight. Sonication produced extracts with lower agar contents and decreased molecular weights. A gelation mechanism is proposed based on the rheological and small angle scattering characterization of the extracts. The formation of strong hydrogels upon cooling was caused by the association of agarose chains into double helices and bundles, the sizes of which depended on the agar purity and molecular weight. These different arrangements at the molecular scale consequently affected the mechanical performance of the obtained hydrogels. Heating of the hydrogels produced a gradual disruption of the bundles; weaker or smaller bundles were formed upon subsequent cooling, suggesting that the process was not completely reversible.
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| 8. |
- van Buggenhout, Sandra, et al.
(författare)
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Structural design of natural plant based foods to promote nutritional quality
- 2012
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Ingår i: Trends in Food Science and Technology. - : Elsevier BV. - 0924-2244 .- 1879-3053. ; 24:1, s. 47-59
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- During traditional industrial processing of fruit and vegetable derived foods, consideration of the eventual retention, bio-accessibility or bio-availability of nutrients has hitherto been a secondary priority. Indeed standard processing of soups and sauces involves treating all ingredients in a similar way, usually by prolonged heat treatment and results in both lowered nutritional value and sensory quality of food products. Such products are typically structured using various additives including starches, gums and stabilizers, which consumers regard as unnatural, rather than exploiting the endogenous structuring potential of the fruit and vegetable ingredients as available at the farm gate. Recent studies undertaken within the EU sponsored 'Healthy Structuring' project have shown how to design an industrially manufactured product with good sensory qualities that is natural and nutritious. The strategy has been to use the inherent structural and nutritional properties of the raw material ingredients, on the one hand to ensure the textural quality of the final product without the use of artificial gums or stabilizers and, on the other hand to optimize the nutritional quality of the final product. This review briefly summarizes both the approach taken and the results obtained within the project.
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