Gelatine, casein and potassium caseinate as distinct wine fining agents: different effects on colour, phenolic compounds and sensory characteristics

Aims: Describe and compare some characteristics, such as molecular weight (MW) distribution and surface charge density of commercial protein fining agents and to enhance the understanding of their effect on wine chemical and sensory characteristics.Methods and results: Protein (casein, potassium caseinate and gelatine) MW distribution was characterised by electrophoresis. These proteins were added to a red and a white wine, in order to evaluate its effect on colour, phenolic compounds and sensory attributes.Conclusion: A band at 30.0 kDa characterised casein and potassium caseinate. Gelatines showed polydispersion on the MW distribution, gelatine GSQ on the higher MW (> 43.0 kDa) and gelatine GL on the lower MW (< 43.0 kDa). Despite the fact that casein and potassium caseinate had similar MW distribution, casein decreased essentially the monomeric ((+) - catechin and (-) - epicatechin) while the potassium caseinate showed a lower influence on these compounds. Also, among the two gelatines used, a different behaviour was observed. The gelatine characterised by a polydispersion below 43.0 kDa depleted more the polymeric tannin fractions than the gelatine characterised by a polydispersion above 43.0 kDa. That gelatine has also decreased colour intensity and coloured anthocyanins of red wine but the hue remains unchanged. Addition of fining agents did not affect greatly the concentration of monomeric anthocyanins. Sensory analysis showed that wines fined with the different proteins presented distinct characteristics.Significance and impact of study: The knowledge of the physico-chemical characteristics, such as MW distribution and surface charge density, is important for wine fining optimisation and consequently for the wine quality.

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INFLUENCE OF SURFACE PRETREATMENT ON THE SURFACE CHARGE DENSITY AT THE INTERFACE BETWEEN MCT MBE AND AL3 ALD

Автометрия ◽

10.15372/aut20200506 ◽

2020 ◽

Keyword(s):

Charge Density ◽

Surface Charge ◽

Surface Charge Density ◽

Surface Pretreatment

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Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

Cells ◽

10.3390/cells10061519 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1519

Author(s):

Leixin Ouyang ◽

Rubia Shaik ◽

Ruiting Xu ◽

Ge Zhang ◽

Jiang Zhe

Keyword(s):

Cell Surface ◽

Charge Density ◽

Surface Charge ◽

Charge Distribution ◽

Surface Charge Density ◽

Single Cells ◽

Fluorescent Light ◽

Fluorescent Nanoparticles ◽

Cell Surface Charge ◽

Surface Charge Distribution

Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle (NP) interactions. Fluorescent nanoparticles (NPs) were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescent light intensity and number of nanoparticles, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, human umbilical vein endothelial cells (HUVECs) and HeLa cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potentials of the two types of cells were obtained, which are in good agreement with the standard electrophoretic light scattering measurement. This method can be used for rapid surface charge mapping of single particles or cells, and can advance cell-surface-charge characterization applications in many biomedical fields.

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Triboelectrification of nanocomposites using identical polymer matrixes with different concentrations of nanoparticle fillers

Journal of Materials Chemistry A ◽

10.1039/d0ta12441a ◽

2021 ◽

Author(s):

Linards Lapčinskis ◽

Artis Linarts ◽

Kaspars Mālnieks ◽

Hyunseung Kim ◽

Kristaps Rubenis ◽

...

Keyword(s):

Charge Density ◽

Surface Charge ◽

Surface Charge Density ◽

Polymer Layers

In this study, we investigate triboelectrification in polymer-based nanocomposites using identical polymer matrixes containing different concentrations of nanoparticles (NPs). The triboelectric surface charge density on polymer layers increased as the...

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Effect of Pre-Fermentative Maceration and Fining Agents on Protein Stability, Macromolecular, and Phenolic Composition of Albariño White Wines: Comparative Efficiency of Chitosan, k-Carrageenan and Bentonite as Heat Stabilisers

Foods ◽

10.3390/foods10030608 ◽

2021 ◽

Vol 10 (3) ◽

pp. 608

Author(s):

Inma Arenas ◽

Miguel Ribeiro ◽

Luís Filipe-Ribeiro ◽

Rafael Vilamarim ◽

Elisa Costa ◽

...

Keyword(s):

Phenolic Compounds ◽

Protein Stability ◽

White Wine ◽

The Other ◽

White Wines ◽

Comparative Efficiency ◽

Fining Agents ◽

Protein Instability ◽

Related Proteins ◽

Protein Stabilisation

In this work, the effect of pre-fermentative skin maceration (PFSM) on the chemical composition of the macromolecular fraction, polysaccharides and proteins, phenolic compounds, chromatic characteristics, and protein stability of Albariño monovarietal white wines was studied. PFSM increased the extraction of phenolic compounds and polysaccharides and reduced the extraction of pathogenesis-related proteins (PRPs). PFSM wine showed significantly higher protein instability. Sodium and calcium bentonites were used for protein stabilisation of wines obtained with PFSM (+PFSM) and without PFSM (−PFSM), and their efficiencies compared to fungal chitosan (FCH) and k-carrageenan. k-Carrageenan reduced the content of PRPs and the protein instability in both wines, and it was more efficient than sodium and calcium bentonites. FCH was unable to heat stabilise both wines, and PRPs levels remained unaltered. On the other hand, FCH decreased the levels of wine polysaccharides by 60%. Sodium and calcium bentonite also decreased the levels of wine polysaccharides although to a lower extent (16% to 59%). k-Carrageenan did not affect the wine polysaccharide levels. Overall, k-carrageenan is suitable for white wine protein stabilisation, having a more desirable impact on the wine macromolecular fraction than the other fining agents, reducing the levels of the wine PRPs without impacting polysaccharide composition.

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Effect of Selected Anionic and Cationic Drugs Affecting the Central Nervous System on Electrical Properties of Phosphatidylcholine Liposomes: Experiment and Theory

International Journal of Molecular Sciences ◽

10.3390/ijms22052270 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2270

Author(s):

Joanna Kotyńska ◽

Monika Naumowicz

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Charge Density ◽

Surface Charge ◽

Surface Charge Density ◽

Barbituric Acid ◽

Membrane Surface ◽

Adsorption Equilibria ◽

Two Component ◽

The Central Nervous System

Interactions between phospholipid membranes and selected drugs affecting the central nervous system (CNS) were investigated. Small, unilamellar liposomes were used as biomimetic cell membrane models. Microelectrophoretic experiments on two-component liposomes were performed using the electrophoretic light scattering technique (ELS). The effect of both positively (perphenazine, PF) and negatively (barbituric acid, BA) charged drugs on zwitterionic L-α-phosphatidylcholine (PC) membranes were analyzed. Experimental membrane surface charge density (d) data were determined as a function of pH. Quantitative descriptions of the adsorption equilibria formed due to the binding of solution ions to analyzed two-component membranes are presented. Binding constants of the solution ions with perphenazine and barbituric acid-modified membranes were determined. The results of our research show that both charged drugs change surface charge density values of phosphatidylcholine membranes. It can be concluded that perphenazine and barbituric acid are located near the membrane surface, interacting electrostatically with phosphatidylcholine polar heads.

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Surface charging parameters of charged particles in symmetrical electrolyte solutions

Physical Chemistry Chemical Physics ◽

10.1039/d0cp02725a ◽

2020 ◽

Vol 22 (35) ◽

pp. 20123-20142

Author(s):

Hadi Saboorian-Jooybari ◽

Zhangxin Chen

Keyword(s):

Charge Density ◽

Surface Charge ◽

Electrolyte Solution ◽

Surface Charge Density ◽

Potential Surface ◽

Research Work ◽

Charged Particles ◽

Electrolyte Solutions ◽

Surface Charging ◽

Curvature Dependence

This research work is directed at development of accurate physics-based formulas for quantification of curvature-dependence of surface potential, surface charge density, and total surface charge for cylindrical and spherical charged particles immersed in a symmetrical electrolyte solution.

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A multi-dielectric-layered triboelectric nanogenerator as energized by corona discharge

Nanoscale ◽

10.1039/c7nr02249b ◽

2017 ◽

Vol 9 (27) ◽

pp. 9668-9675 ◽

Cited By ~ 28

Author(s):

Jia Jia Shao ◽

Wei Tang ◽

Tao Jiang ◽

Xiang Yu Chen ◽

Liang Xu ◽

...

Keyword(s):

Charge Density ◽

Surface Charge ◽

Corona Discharge ◽

Surface Charge Density ◽

High Surface ◽

Cycling Stability ◽

Triboelectric Nanogenerator ◽

Excellent Cycling Stability ◽

Vertical Contact ◽

High Surface Charge Density

A multi-dielectric-layered vertical contact-separation mode TENG through a corona discharge approach results in outstanding output performances, i.e., a high surface charge density of 283 μC m−2 and excellent cycling stability (92.6% retention after 200 000 cycles).

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