Subphase exchange experiments with the pendant drop technique

Abstract

This review aims to compile the experimental work done, using the pendant drop subphase exchange in the last decade, and how its use has provided new insights into the surface/interfacial properties of many different materials. Special emphasis is placed on recent work regarding simulation of in vitro digestion in order to address issues relating to metabolism degradation profiles. The use of this methodology when dealing with interfacial studies allows setting the foundations of interfacial engineering technology. Based on subphase exchange experiments, we aim to develop models for competitive adsorption of different compounds at the interface and build up layer-by-layer interfacial structures. Future challenges comprise the design of finely adjusted nanoengineering systems, based on multilayer assemblies with tailored functionalities, to match the application demand.

Improved digestibility of β-lactoglobulin by pulsed light processing: a dilatational and shear study

“…No significant temperature increase was found at the maximum total fluence. 29 This device has been implemented on the basis of the single subphase exchange device, where the normal capillary tip was substituted by an arrangement of two coaxial capillaries, connected each to one of the channels of a 75 specific micro-injector, which can operate independently 30 (Spanish Patent, registration number P9801626), to achieve a fully automated subphase multi-exchange device described in detail elsewhere 15,19 . The OCTOPUS computer software DINATEN© has been also fully programmed at the University of 80 were maintained at amplitude values of less than 5% variation, in order to avoid excessive perturbation of the interfacial layer, while the measurement frequencies (ν) were set to 0.01, 0.1 and 1 Hz.…”

“…Accordingly, it this work we evaluate the digestibility of PL-BLG as compared to BLG by simulating in-vitro digestion in bulk and 25 at the oil-water interface. Digestibility of BLG in solution has been reported in the literature 9 whereas digestibility at interfaces is much scarce 6,15 . Proteins are emulsified along the gastrointestinal tract owing to the mixture with biosurfactants and peristaltic movements and therefore studying their enzymatic 30 degradation at interfaces is very important 16 .…”

Assessing in vitro digestibility of food biopreservative AS-48

“…Biosurfactants in the diet are emulsified along the gastrointestinal tract owing to the mixture with biosurfactants and peristaltic movements. Hence, it is important to study the enzymatic degradation both in bulk solution and at interfaces (Del Castillo-Santaella, Sanmartin, Cabrerizo-Vílchez, Arboleya, & Maldonado-valderrama, 2014;Hur, Lim, Decker, & McClements, 2011;Maldonado-Valderrama, Holgado-Terriza, Torcello-Gomez, & Cabrerizo-Vilchez, 2013;Maldonado-Valderrama, Torcello-Gómez, del Castillo-Santaella, Holgado-Terriza, & Cabrerizo-Vílchez, 2015). Based on the function and the biotechnological applications of AS-48, we have applied a standardized in vitro digestion model (Mitropoulos, Mütze, & Fischer, 2014).…”

Encapsulation of lipids to delay lipolysis and reduce food intake

“…When used as a mixture, bile and lipase gave the same response on a bare oil-water interface as found for bile only (Figure 4.4a, brown line), indicating that bile components dominate the interfacial tension reduction, which can be expected for low molecular weight surfactants (i.e., bile salts) compared to proteins (Maldonado-Valderrama et al, 2015;Sagis & Scholten, 2014). Bile components have previously been reported to affect lipase adsorption in various ways, ranging from promoting effects Torcello-Gómez, Maldonado-Valderrama, de Vicente, et al, 2011) to complete inhibition (Reis et al, 2009).…”

“…Addition of a secondary layer slightly decreased the extent of interface disruption by bile salts and lipase, but did not change the initial rate of displacement and had minor effect on the lipolysis rate, if any, and it was not possible to understand the full behaviour of all lipolytic components at multilayered oil-water interfaces (Pan & Nitin, 2016). Through the recent introduction of phase exchange in drop techniques, as nicely reviewed by Maldonado-Valderrama et al (2015), the effect of digestive components on interfacial tension and interfacial rheology can now be studied (del Castillo-Santaella et al, 2015). Here we used this approach to systematically investigate the influence of lipolytic duodenal compounds on the behaviour of model biopolymer films prepared by the LbL technique (whey protein isolate and pectin) at the oil-water interface, in a droplet volume tensiometer.…”