Atomic force microscopy for determining surface interactions of relevance for food foams and emulsions

Krasowska, Marta; Prestidge, Clive A.; Beattie, David A.

doi:10.1002/9781118765616.ch16

Cited by 7 publications

(11 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, after that the aggregate growth commences again [8]. Atomic force microscopy (AFM), which has been used for determining surface interactions of relevance to food foams [44], has been applied also to investigate the adhesion of HFBII aggregates to hydrophobin adsorption layers at the air/water interface [33].…”

Section: Introductionmentioning

confidence: 99%

Production and characterization of stable foams with fine bubbles from solutions of hydrophobin HFBII and its mixtures with other proteins

Dimitrova

Petkov

Kralchevsky

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

Hydrophobins are proteins that are excellent foam stabilizers. We investigated the effects of pH and addition of other proteins on the foaminess, bubble size, and stability of foams from aqueous solutions of the protein HFBII hydrophobin. The produced stable foams have bubbles of radii smaller than 40 µm that obey the lognormal distribution. The overrun of most foams is in the range from 5 to 8, which indicates a good foaminess. The foam longevity is characterized by the time dependences of the foam volume and weight. A combined quantitative criterion for stability, the degree of foam conservation, is proposed. The produced foams are stable for at least 12-17 days. The high foam stability can be explained with the formation of dense hydrophobin adsorption layers, which are impermeable to gas transfer and block the Ostwald ripening (foam disproportionation). In addition, the population of small bubbles formed in the HFBII solutions blocks the drainage of water through the Plateau borders in the foam. The variation of pH does not essentially affect the foaminess and foam stability. The addition of "regular" proteins, such as beta-lactoglobulin, ovalbumin and bovine serum albumin, to the HFBII solutions does not deteriorate the quality and stability of the produced foams up to 94% weight fraction of the added protein. The results and conclusions from the present study could be useful for the applications of hydrophobins as foam stabilizers.

show abstract

Section: Introductionmentioning

confidence: 99%

Production and characterization of stable foams with fine bubbles from solutions of hydrophobin HFBII and its mixtures with other proteins

Dimitrova

Petkov

Kralchevsky

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

show abstract

“…Other surface forces such as hydration, hydrophobic, steric, depletion, and/or bridging forces can be dominant in determining the stability of the intervening liquid film, depending on the nature of the system, which includes the presence of surface active species and/or polymers residing at or near the liquid−liquid interface. 2 AFM has been extensively used to study nanoscale forces between rigid surfaces. Knowing the spring constant of the AFM cantilever, the magnitude of the force as a function of separation distance between rigid surfaces can be readily obtained.…”

Section: ■ Introductionmentioning

confidence: 99%

Dynamic Interactions between a Silica Sphere and Deformable Interfaces in Organic Solvents Studied by Atomic Force Microscopy

et al. 2016

View full text Add to dashboard Cite

Recent studies have successfully measured surface forces using 8 atomic force microscope (AFM) and modeled surface deformations using the Stokes−Reynolds−Young−Laplace (SRYL) equations for particle−droplet, particle−bubble, droplet−droplet, and bubble−bubble systems in various solutions. The current work focuses on interactions between spherical silica particles and a viscoelastic interface of water droplets in crude oil. The self-assembly of surface active natural polyaromatic molecules (NPAMs) at the oil−water interface has previously been shown to change a viscous dominant oil−water interface to an elastic dominant interface upon aging, due to gradual formation of rigid interfacial networks. AFM was used to measure the interactions between a small silica sphere (D ≈ 8 m) and a deformable water droplet (D ≈ 70 m), which exhibits time-dependent interfacial viscoelasticity in NPAM solutions. Unlike the systems studied previously, the measured deformation shown as a repulsive force over the region of constant compliance could not be modeled adequately by the conventional SRYL equations which are applicable only to purely Laplacian interfaces. As the water droplet ages in NPAM solutions, a rigid "skin" forms at the oil−water interface, with the interface exhibiting increased elasticity. Over a short aging period (up to 15 min in NPAM-in-toluene solution), interfacial deformation is well predicted by the SRYL model. However, upon further exposure to the NPAM solution, droplet deformation is over predicted by the model. Physical properties of this mechanical barrier as a function of interfacial aging were further investigated by measuring interfacial tension, dilatational rheology, and interfacial "crumpling" (non-smooth, non-Laplacian interface) upon droplet volume reduction. By introducing a viscoelasticity parameter to account for interfacial stiffening and using experimentally determined elasticity, we are able to correct this discrepancy and predict droplet deformation under AFM cantilever compression. This parameter appears to be important for modeling non-Laplacian systems of significant viscoelastic contributions, such as biological cell membranes or polymer blends.

show abstract

“…When the piezoelectric scanner retracts beyond the distance of the initial jump contact, due to the adhesive forces between the tip and the sample surface, they remain in contact (E point), and this leads to a hysteresis between the approaching and retracting curves. Since the forces induced by the cantilever deflection are larger than the adhesive forces, the tip separates from the sample surface (F point) and returns to its starting deflection point (G point) (Siedlecki and Marchant 1998;Jandt 2001;Krasowska, Prestidge, and Beattie 2014). From the force-distance curve, the force interactions between the tip and sample can be determined when the spring constants of the cantilever are known.…”

Section: Force Measurementmentioning

confidence: 99%

An overview of nanoemulsion characterization via atomic force microscopy

Abik

Mikkonen

2021

Critical Reviews in Food Science and Nutrition

View full text Add to dashboard Cite

Nanoemulsion-based systems are widely applied in food industries for protecting active ingredients against oxidation and degradation and controlling the release rate of active core ingredients under particular conditions. Visualizing the interface morphology and measuring the interfacial interaction forces of nanoemulsion droplets are essential to tailor and design intelligent nanoemulsion-based systems. Atomic force microscopy (AFM) is being established as an important technique for interface characterization, due to its unique advantages over traditional imaging and surface force-determining approaches. However, there is a gap in knowledge about the applicability of AFM in characterizing the droplet interface properties of nanoemulsions. This review aims to describe the fundamentals of the AFM technique and nanoemulsions, mainly focusing on the recent use of AFM to investigate nanoemulsion properties. In addition, by reviewing interfacial studies on emulsions in general, perspectives for the further development of AFM to study nanoemulsions are also discussed.

show abstract

Atomic force microscopy for determining surface interactions of relevance for food foams and emulsions

Cited by 7 publications

References 64 publications

Production and characterization of stable foams with fine bubbles from solutions of hydrophobin HFBII and its mixtures with other proteins

Production and characterization of stable foams with fine bubbles from solutions of hydrophobin HFBII and its mixtures with other proteins

Dynamic Interactions between a Silica Sphere and Deformable Interfaces in Organic Solvents Studied by Atomic Force Microscopy

An overview of nanoemulsion characterization via atomic force microscopy

Contact Info

Product

Resources

About