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Kaczmarczyk K, Kruk J, Ptaszek P, Ptaszek A. Plantago Ovata Husk: An Investigation of Raw Aqueous Extracts. Osmotic, Hydrodynamic and Complex Rheological Characterisation. Molecules 2023; 28:molecules28041660. [PMID: 36838648 PMCID: PMC9962041 DOI: 10.3390/molecules28041660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
The aim of the study was to characterize raw aqueous extracts from Plantago ovata husk in terms of molecular chain mass, osmotic, hydrodynamic, and rheological properties. The raw extracts used in this study have not been yet investigated in the indicated research area. Determination of the molecular weight of the chains present in the extract was performed by gel permeation chromatography (GPC). Osmotic properties were characterized using membrane osmometry. Rheological properties were investigated via classical rotational rheology with normal force measurements, as well as less common but equally important measurements of extensional viscosity. Two types of chains with an average molecular mass of 200 and 1780 kDa were found. The values of the first virial coefficient (B2) indicate the predominance of biopolymer-biopolymer interactions. The hydrodynamic radius established at 25 and 30 °C was 74 and 67 nm, respectively, and lower than at 40 °C (>600 nm). The first critical concentration was determined: c*=0.11 g·dL-1. The dominance of negative normal force values resulting from the formation of a pseudo-gel structure of the heteroxylates was demonstrated. Extensional viscosity measurement results revealed that the studied extracts cannot be treated as simple shear-thinning fluids, as indicated by shear flow, but should be considered as viscoelastic fluids.
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Affiliation(s)
- Kacper Kaczmarczyk
- Department of Engineering and Machinery in Food Industry, Faculty of Food Technology, University of Agriculture in Kraków, ul. Balicka 122, 30-149 Kraków, Poland
- Correspondence:
| | - Joanna Kruk
- Department of Engineering and Machinery in Food Industry, Faculty of Food Technology, University of Agriculture in Kraków, ul. Balicka 122, 30-149 Kraków, Poland
| | - Paweł Ptaszek
- Department of Fermentation Technology and Microbiology, Faculty of Food Technology, University of Agriculture in Kraków, ul. Balicka 122, 30-149 Kraków, Poland
| | - Anna Ptaszek
- Department of Engineering and Machinery in Food Industry, Faculty of Food Technology, University of Agriculture in Kraków, ul. Balicka 122, 30-149 Kraków, Poland
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Petkova H, Jarek E, Doychinov M, Krzan M, Mileva E. Synergy in Aqueous Systems Containing Bioactive Ingredients of Natural Origin: Saponin/Pectin Mixtures. Polymers (Basel) 2022; 14:polym14204362. [PMID: 36297940 PMCID: PMC9610430 DOI: 10.3390/polym14204362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022] Open
Abstract
Biocompatible and biodegradable ingredients of natural origin are widely used in the design of foam and emulsion systems with various technological applications in the food, cosmetics and pharmaceutical industries. The determination of the precise composition of aqueous solution formulations is a key issue for the achievement of environmentally-friendly disperse systems with controllable properties and reasonable stability. The present work is focused on the investigation of synergistic interactions in aqueous systems containing Quillaja saponins and Apple pectins. Profile analysis tensiometer (PAT-1) is applied to study the surface tension and surface dilational rheology of the adsorption layers at the air/solution interface. The properties and the foam films (drainage kinetics, film thickness, disjoining pressure isotherm, critical pressure of rupture) are investigated using the thin-liquid-film (TLF) microinterferometric method of Scheludko–Exerowa and the TLF-pressure-balance technique (TLF-PBT). The results demonstrate that the structure and stability performance of the complex aqueous solutions can be finely tuned by changing the ratio of the bioactive ingredients. The attained experimental data evidence that the most pronounced synergy effect is registered at a specific saponin:pectin ratio. The obtained information is essential for the further development of aqueous solution formulations intended to achieve stable foams based on mixtures of Quillaja saponins and Apple pectins in view of future industrial, pharmaceutical and biomedical applications.
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Affiliation(s)
- Hristina Petkova
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str. Bl. 11, 1113 Sofia, Bulgaria
| | - Ewelina Jarek
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 8 “Niezapominajek” Str., 30239 Krakow, Poland
| | - Mitko Doychinov
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str. Bl. 11, 1113 Sofia, Bulgaria
| | - Marcel Krzan
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 8 “Niezapominajek” Str., 30239 Krakow, Poland
| | - Elena Mileva
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str. Bl. 11, 1113 Sofia, Bulgaria
- Correspondence:
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Kierulf AV, Whaley JK, Liu W, Smoot JT, Jenab E, Perez Herrera M, Abbaspourrad A. Heat- and shear-reversible networks in food: A review. Compr Rev Food Sci Food Saf 2022; 21:3405-3435. [PMID: 35765752 DOI: 10.1111/1541-4337.12988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/27/2022]
Abstract
While nature behaves like an irreversible network with respect to entropy and time, certain systems in nature exist that are, to some extent, reversible. The property of reversibility imparts unique benefits to systems that possess them, making them suitable for designing self-healing, stimuli-responsive, and smart materials that can be used in widely divergent fields. Reversible networks are currently being exploited for applications in tissue engineering, drug delivery, and soft robotics. They are also being utilized as low-calorie fat mimetics with melt-in-your-mouth textures, as well as being explored as potential scaffolds for three-dimensional (3D) printable food, among other applications. This review aims to gather representative examples of heat- and shear-reversible networks in the food science literature from the last 30 or so years, in other words, reversible food gels made either from linear biopolymers or from colloidal, particulate dispersions, including those that have been modified specifically to induce reversibility. An overview of the network mechanisms involved that impart reversibility, including a discussion of the strength and range of forces involved, will be highlighted. A model that explains why certain networks are thermoreversible while others are shear-reversible, and why others are both, will also be proposed. A fundamental understanding of these mechanisms will prove invaluable when designing reversible networks in the future, making possible the precise control of their properties, thus fostering innovative applications within the food industry and beyond.
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Affiliation(s)
- Arkaye V Kierulf
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA.,Tate & Lyle Solutions USA LLC, Hoffman Estates, Illinois, USA
| | - Judith K Whaley
- Tate & Lyle Solutions USA LLC, Hoffman Estates, Illinois, USA
| | - Weichang Liu
- Tate & Lyle Solutions USA LLC, Hoffman Estates, Illinois, USA
| | - James T Smoot
- Tate & Lyle Solutions USA LLC, Hoffman Estates, Illinois, USA
| | - Ehsan Jenab
- Tate & Lyle Solutions USA LLC, Hoffman Estates, Illinois, USA
| | | | - Alireza Abbaspourrad
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
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Huang ST, Yang CH, Lin PJ, Su CY, Hua CC. Multiscale structural and rheological features of colloidal low-methoxyl pectin solutions and calcium-induced sol-gel transition. Phys Chem Chem Phys 2021; 23:19269-19279. [PMID: 34524316 DOI: 10.1039/d1cp02778f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The multiscale structural and rheological features of a series of dilute and semidilute low-methoxyl (LM) pectin solutions and a representative pectin/calcium sol-gel sample were systematically explored using a comprehensive combination of dynamic (DLS) and static light/X-ray scattering (SALS/SLS/SAXS), rheology, and microscopy (OM/SEM) characterizations. The study focused on the rarely explored colloidal aspect of LM pectin solutions and sol-gel transition, in contrast to the polymeric features extensively explored in previous studies. A highly uniform colloid-like, micron-sized agglomerate species was revealed in dilute solutions, with a progressively increased degree of flocculation in the semidilute regime (≥1.5 wt%). The agglomerate species in these solutions was resolved to be formed by random associations of individual pectin chains (L = 30 nm, r = 0.4 nm). Adding a critical amount of Ca2+ (10 wt%) to a semidilute solution (2 wt%) has an instant and pronounced effect of enhancing the agglomerate flocculation and resulting in a locally jammed state. Meanwhile, the agglomerate interior underwent microstructural transformation, leading to hierarchical structures defined by intermediate (spherical) aggregate species (Rg,aggregate ≈ 150 nm) and its packing cylindrical bundle (d ≈ 4 nm) composed of five pectin chains. Novel rheological features observed during the LM pectin/Ca2+ sol-gel transition include the following: the dynamic modulus data exhibited excellent TTS (gelling time/relaxation time superposition) as previously observed for weakly attractive colloidal gels. Three yield points were noticed for the final gel sample, suggested to mark the bond breaking of the cluster network, cage breaking of the resulting jammed flocculates, and, eventually, breakup of a flocculate into smaller agglomerates with increasing stress amplitude.
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Affiliation(s)
- Ssu-Ting Huang
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Cheng-Hao Yang
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Peng-Ju Lin
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Chien-You Su
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
| | - Chi-Chung Hua
- Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan.
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Red currant pectin: The physicochemical characteristic of pectin solutions in dilute and semi dilute regimes. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106420] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gawkowska D, Cieśla J, Zdunek A, Cybulska J. The Effect of Concentration on the Cross-Linking and Gelling of Sodium Carbonate-Soluble Apple Pectins. Molecules 2019; 24:E1635. [PMID: 31027264 PMCID: PMC6514935 DOI: 10.3390/molecules24081635] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/20/2019] [Accepted: 04/22/2019] [Indexed: 11/16/2022] Open
Abstract
The cross-linking and gelation of low-methoxy pectins are basic processes commonly used in different industries. The aim of this research was to evaluate the cross-linking process of the sodium carbonate-soluble pectins (named DASP) extracted from apples, characterized by a low degree of methylesterification as a function of its concentration in water (CDASP). The cross-linking process was studied with a dynamic light scattering method, atomic force microscope (AFM), viscosity and pH measurements. An increase in CDASP above 0.01% resulted in a decrease in the aggregation index (AI) and the change of its sign from positive to negative. The value of AI = 0 occurred at CDASP = 0.33 ± 0.04% and indicated the formation of a pectin network. An increase in CDASP caused the changes in viscosity of pectin solutions and the nanostructure of pectins spin-coated on mica observed with AFM, which confirmed results obtained. The hydrogen bonds were involved in the cross-linking process.
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Affiliation(s)
- Diana Gawkowska
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Jolanta Cieśla
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Artur Zdunek
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Justyna Cybulska
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
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Pancerz M, Ptaszek A, Sofińska K, Barbasz J, Szlachcic P, Kucharek M, Łukasiewicz M. Colligative and hydrodynamic properties of aqueous solutions of pectin from cornelian cherry and commercial apple pectin. Food Hydrocoll 2019. [DOI: 10.1016/j.foodhyd.2018.10.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Singh M, Singh S, Inamuddin, Asiri AM. IFT and friccohesity study of formulation, wetting, dewetting of liquid systems using oscosurvismeter. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.08.067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Assifaoui A, Lerbret A, Uyen HTD, Neiers F, Chambin O, Loupiac C, Cousin F. Structural behaviour differences in low methoxy pectin solutions in the presence of divalent cations (Ca(2+) and Zn(2+)): a process driven by the binding mechanism of the cation with the galacturonate unit. SOFT MATTER 2015; 11:551-560. [PMID: 25425418 DOI: 10.1039/c4sm01839g] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this paper, we compare the interactions between low methoxy pectin (LMP) and either Ca(2+) or Zn(2+) in semi-dilute solutions. Intrinsic viscosity and turbidity measurements reveal that pectin-calcium solutions are more viscous, but yet less turbid, than pectin-zinc ones. To get a molecular understanding of the origin of this rather unexpected behavior, we further performed isothermal titration calorimetry, small angle neutron scattering experiments, as well as molecular dynamics simulations. Our results suggest that calcium cations induce the formation of a more homogeneous network of pectin than zinc cations do. The molecular dynamics simulations indicate that this difference could originate from the way the two cations bind to the galacturonate unit (Gal), the main component of LMP: zinc interacts with both carboxylate and hydroxyl groups of Gal, in a similar way to that described in the so-called egg-box model, whereas calcium only interacts with carboxylate groups. This different binding behavior seems to arise from the stronger interaction of water molecules with zinc than with calcium. Accordingly, galacturonate chains are more loosely associated with each other in the presence of Ca(2+) than with Zn(2+). This may improve their ability to form a gel, not only by dimerization, but also by the formation of point-like cross-links. Overall, our results show that zinc binds less easily to pectin than calcium does.
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Affiliation(s)
- Ali Assifaoui
- UMR PAM, AgroSup Dijon - Université de Bourgogne, Dijon, France.
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11
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Basak R, Bandyopadhyay R. Formation and rupture of Ca(2+) induced pectin biopolymer gels. SOFT MATTER 2014; 10:7225-7233. [PMID: 25160564 DOI: 10.1039/c4sm00748d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
When calcium salts are added to an aqueous solution of polysaccharide pectin, ionic cross-links form between pectin chains, giving rise to a gel network in dilute solution. In this work, dynamic light scattering (DLS) is employed to study the microscopic dynamics of the fractal aggregates (flocs) that constitute the gels, while rheological measurements are carried out to study the process of gel rupture. As the calcium salt concentration is increased, DLS experiments reveal that the polydispersity of the flocs increase simultaneously with the characteristic relaxation times of the gel network. Above a critical salt concentration, the flocs become interlinked to form a reaction-limited fractal gel network. Rheological studies demonstrate that the limits of the linear rheological response and the critical stresses required to rupture these networks both decrease with the increase in salt concentration. These features indicate that the ion-mediated pectin gels studied here lie in a 'strong link' regime that is characterised by inter-floc links that are stronger than intra-floc links. A scaling analysis of the experimental data presented here demonstrates that the elasticities of the individual fractal flocs exhibit power-law dependences on the added salt concentration. We conclude that when both pectin and salt concentrations are increased, the number of fractal flocs of pectin increases simultaneously with the density of crosslinks, giving rise to very large values of the bulk elastic modulus.
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Affiliation(s)
- Rajib Basak
- Soft Condensed Matter Group, Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560 080, India.
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Characterisation of commercial LM-pectin in aqueous solution. Carbohydr Polym 2013; 92:1133-42. [DOI: 10.1016/j.carbpol.2012.09.100] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 09/24/2012] [Accepted: 09/28/2012] [Indexed: 11/17/2022]
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13
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Nesic AR, Trifunovic SS, Grujic AS, Velickovic SJ, Antonovic DG. Complexation of amidated pectin with poly(itaconic acid) as a polycarboxylic polymer model compound. Carbohydr Res 2011; 346:2463-8. [PMID: 21943549 DOI: 10.1016/j.carres.2011.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/05/2011] [Accepted: 08/23/2011] [Indexed: 11/17/2022]
Abstract
Complexes based on amidated pectin (AP) and poly(itaconic acid) (PIA) were prepared by casting films from solutions of AP and PIA in different ratios with the pectin amount ranging from 10% to 90% by mass. The complexes were investigated by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG). In all investigated ratios of AP/PIA glassy transparent films with a uniform structure were obtained. The results of elemental analysis confirmed the composition of the complexes, and FTIR spectroscopy has shown carboxylic and amide peak shifting, indicating complex formation between AP and PIA. Comparison of thermograms of AP/PIA films with different ratios of AP indicated that the increase of the amount of AP increases the thermal stability of the films by retarding the onset of the main degradation processes.
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Affiliation(s)
- Aleksandra R Nesic
- Vinca Institute of Nuclear Sciences, University of Belgrade, PO Box 522, Belgrade RS-11001, Serbia.
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14
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Light scattering study on the dynamic behaviour of cellulose inclusion complex in LiOH/urea aqueous solution. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.06.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Cruz M, Freitas F, Torres CA, Reis MA, Alves VD. Influence of temperature on the rheological behavior of a new fucose-containing bacterial exopolysaccharide. Int J Biol Macromol 2011; 48:695-9. [DOI: 10.1016/j.ijbiomac.2011.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/15/2011] [Accepted: 02/21/2011] [Indexed: 10/18/2022]
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Cavallaro G, Lazzara G, Milioto S. Dispersions of nanoclays of different shapes into aqueous and solid biopolymeric matrices. Extended physicochemical study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1158-1167. [PMID: 21188987 DOI: 10.1021/la103487a] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Dispersions of nanofillers into aqueous and solid biopolymeric matrices were studied from the physicochemical viewpoint. This work was carried out based on the idea that the combination of biopolymers, derived from renewable resources, and nanofiller, environmentally friendly, may form a new generation of nanomaterials with excellent and unique properties at low cost. To this purpose, two pectins with different degrees of methyl esterification and nanoclays like halloysite and laponite RD were selected. The thermodynamic and structural studies on the aqueous mixtures of pectin and nanoclay were able to discriminate the interactions, which control the adsorption of pectin onto the filler and the aggregation of both pectin and clay particles. The gained insights were useful to interpret the mesoscopic structure of the nanocomposites (prepared from the aqueous mixtures by means of the casting method) evidenced by SEM, thermal stability, tensile properties, and transparency investigations. The attained knowledge represents a basic point for designing new hybrid nanostructures in both the aqueous and the solid phase for specific purposes.
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Affiliation(s)
- Giuseppe Cavallaro
- Dipartimento di Chimica Fisica F. Accascina, Università degli Studi di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
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Espino S, Schenk HJ. Mind the bubbles: achieving stable measurements of maximum hydraulic conductivity through woody plant samples. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:1119-32. [PMID: 21147811 PMCID: PMC3022400 DOI: 10.1093/jxb/erq338] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 10/04/2010] [Accepted: 10/08/2010] [Indexed: 05/03/2023]
Abstract
The maximum specific hydraulic conductivity (k(max)) of a plant sample is a measure of the ability of a plants' vascular system to transport water and dissolved nutrients under optimum conditions. Precise measurements of k(max) are needed in comparative studies of hydraulic conductivity, as well as for measuring the formation and repair of xylem embolisms. Unstable measurements of k(max) are a common problem when measuring woody plant samples and it is commonly observed that k(max) declines from initially high values, especially when positive water pressure is used to flush out embolisms. This study was designed to test five hypotheses that could potentially explain declines in k(max) under positive pressure: (i) non-steady-state flow; (ii) swelling of pectin hydrogels in inter-vessel pit membranes; (iii) nucleation and coalescence of bubbles at constrictions in the xylem; (iv) physiological wounding responses; and (v) passive wounding responses, such as clogging of the xylem by debris. Prehydrated woody stems from Laurus nobilis (Lauraceae) and Encelia farinosa (Asteraceae) collected from plants grown in the Fullerton Arboretum in Southern California, were used to test these hypotheses using a xylem embolism meter (XYL'EM). Treatments included simultaneous measurements of stem inflow and outflow, enzyme inhibitors, stem-debarking, low water temperatures, different water degassing techniques, and varied concentrations of calcium, potassium, magnesium, and copper salts in aqueous measurement solutions. Stable measurements of k(max) were observed at concentrations of calcium, potassium, and magnesium salts high enough to suppress bubble coalescence, as well as with deionized water that was degassed using a membrane contactor under strong vacuum. Bubble formation and coalescence under positive pressure in the xylem therefore appear to be the main cause for declining k(max) values. Our findings suggest that degassing of water is essential for achieving stable and precise measurements of k(max) through woody plant samples. For complete rehydration of woody samples, incubation in water under vacuum for 24 h is suggested as a reliable technique that avoids bubble problems associated with flushing under high positive pressure.
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Affiliation(s)
| | - H. Jochen Schenk
- Department of Biological Science, California State University Fullerton, PO Box 6850, Fullerton, CA 92834-6850, USA
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Fraeye I, Duvetter T, Doungla E, Van Loey A, Hendrickx M. Fine-tuning the properties of pectin–calcium gels by control of pectin fine structure, gel composition and environmental conditions. Trends Food Sci Technol 2010. [DOI: 10.1016/j.tifs.2010.02.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Competition of copper and/or calcium in nickel–pectin interaction by potentiometric and voltammetric techniques. Bioelectrochemistry 2009; 77:31-6. [DOI: 10.1016/j.bioelechem.2009.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 05/07/2009] [Accepted: 05/23/2009] [Indexed: 11/19/2022]
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20
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Beheshti N, Zhu K, Kjøniksen AL, Nyström B. Interaction behaviors in aqueous solutions of negatively and positively charged hydrophobically modified hydroxyethylcellulose in the presence of an anionic surfactant. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2008.06.030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Richter S. Recent Gelation Studies on Irreversible and Reversible Systems with Dynamic Light Scattering and Rheology - A Concise Summary. MACROMOL CHEM PHYS 2007. [DOI: 10.1002/macp.200700285] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Structure and dynamics of aqueous mixtures of an anionic cellulose derivative and anionic or cationic surfactants. Colloids Surf A Physicochem Eng Asp 2006. [DOI: 10.1016/j.colsurfa.2005.12.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tho I, Kjøniksen AL, Knudsen KD, Nyström B. Effect of solvent composition on the association behavior of pectin in methanol–water mixtures. Eur Polym J 2006. [DOI: 10.1016/j.eurpolymj.2005.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Bu H, Kjøniksen AL, Nyström B. Effects of pH on dynamics and rheology during association and gelation via the Ugi reaction of aqueous alginate. Eur Polym J 2005. [DOI: 10.1016/j.eurpolymj.2005.02.035] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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