The aim of this research is to quantify the competitive adsorption of a whey protein concentrate (WPC) and hydroxypropyl-methyl-cellulose (HPMC so called E4M, E50LV and F4M) at the air-water interface by means of dynamic surface tensiometry and Brewster angle microscopy (BAM). These biopolymers are often used together in many food applications. The concentration of both protein and HPMC, and the WPC/HPMC ratio in the aqueous bulk phase were variables, while pH (7), the ionic strength (0.05 M) and temperature (20 degrees C) were kept constant. The differences observed between mixed systems were in accordance with the relative bulk concentration of these biopolymers (C(HPMC) and C(WPC)) and the molecular structure of HPMC. At short adsorption times, the results show that under conditions where both WPC and HPMC could saturate the air-water interface on their own or when C(HPMC) > or = C(WPC), the polysaccharide dominates the surface. At concentrations where none of the biopolymers was able to saturate the interface, a synergistic behavior was observed for HPMC with lower surface activity (E50LV and F4M), while a competitive adsorption was observed for E4M (the HPMC with the highest surface activity). At long-term adsorption the rate of penetration controls the adsorption of mixed components. The results reflect complex competitive/synergistic phenomena under conditions of thermodynamic compatibility or in the presence of a "depletion mechanism". Finally, the order in which the different components reach the interface will influence the surface composition and the film properties.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jcis.2009.04.011 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Langmuir Monolayer as a Model Membrane System for Studying the Interactions of Poly(Butyl Cyanoacrylate) Nanoparticles with Phospholipids at the Air/Water Interface.
Membranes (Basel)
December 2024
Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University St. Kliment Ohridski, 1 "James Bourchier" Blvd., 1164 Sofia, Bulgaria.
Poly(butyl cyanoacrylate) (PBCA) nanoparticles have numerous applications, including drug and gene delivery, molecular imaging, and cancer therapy. To uncover the molecular mechanisms underlying their interactions with cell membranes, we utilized a Langmuir monolayer as a model membrane system. This approach enabled us to investigate the processes of penetration and reorganization of PBCA nanoparticles when deposited in a phospholipid monolayer subphase.
View Article and Find Full Text PDFDesigned Synthesis of Mesoporous sp Carbon-Conjugated Benzothiadiazole Covalent Organic Frameworks for Artificial Photosynthesis of Hydrogen Peroxide.
ACS Appl Mater Interfaces
December 2024
Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Artificial photosynthesis of hydrogen peroxide (HO) from ambient air, water, and sunlight has attracted considerable attention recently. Despite being extremely challenging to synthesis, sp carbon-conjugated covalent organic frameworks (COFs) can be powerful and efficient materials for the photosynthesis of HO due to desirable properties. Herein, we report the designed synthesis of an sp carbon-conjugated COF, BTD-spc-COF, from benzothiadiazole and triazine units with high crystallinity and ultralarge mesopores (∼4 nm).
View Article and Find Full Text PDFRapid N2O Formation from N2 on Water Droplet Surfaces.
Angew Chem Int Ed Engl
December 2024
University of Pennsylvania, Department of Earth and Environmental Science and Department of Chemistry, 251 Hayden Hall, 240 South 33rd Street, 19104-6316, Philadelphia, UNITED STATES OF AMERICA.
Nitrogen (N2) has long been considered as stable atmospheric reservoir for N element and has a persistence time of hundreds of years. This study reveals that oxygen (O2) at typical tropospheric concentrations can rapidly activate N2, leading to substantial production of nitrous oxide (N2O), the third most impactful greenhouse gas, at rates approaching 2.83 ± 0.
View Article and Find Full Text PDFCapillary-driven self-assembly of soft ellipsoidal microgels at the air-water interface.
Proc Natl Acad Sci U S A
December 2024
Institute of Physical Chemistry, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen 52074, Germany.
The adsorption of ellipsoidal colloidal particles on liquid interfaces induces interfacial deformation, resulting in anisotropic interface-mediated interactions and the formation of superstructures. Soft prolate-shaped microgels at the air-water interface offer an ideal model for studying spontaneous capillary-driven self-assembly due to their tunable aspect ratio, controlled functionality, and softness. These microgels consist of a polystyrene core surrounded by a cross-linked, fluorescently labeled poly([Formula: see text]-isopropylmethylacrylamide) shell.
View Article and Find Full Text PDFThermostable conformational transition unfavorable to the foaming stability of ovalbumin: Emphasizing structure and function relationship.
Int J Biol Macromol
December 2024
National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address:
Storage of shell eggs converts natural ovalbumin (N-OVA) into its more thermostable forms (S-OVA). This conversion may be associated with deterioration in the foaming properties of the stored shell egg. Thus, the foaming behavior of N-OVA and S-OVA, especially their performance at different pH conditions, was conducted.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!