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Gochev GG, Campbell RA, Schneck E, Zawala J, Warszynski P. Exploring proteins at soft interfaces and in thin liquid films - From classical methods to advanced applications of reflectometry. Adv Colloid Interface Sci 2024; 329:103187. [PMID: 38788307 DOI: 10.1016/j.cis.2024.103187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/12/2024] [Accepted: 05/12/2024] [Indexed: 05/26/2024]
Abstract
The history of the topic of proteins at soft interfaces dates back to the 19th century, and until the present day, it has continuously attracted great scientific interest. A multitude of experimental methods and theoretical approaches have been developed to serve the research progress in this large domain of colloid and interface science, including the area of soft colloids such as foams and emulsions. From classical methods like surface tension adsorption isotherms, surface pressure-area measurements for spread layers, and surface rheology probing the dynamics of adsorption, nowadays, advanced surface-sensitive techniques based on spectroscopy, microscopy, and the reflection of light, X-rays and neutrons at liquid/fluid interfaces offers important complementary sources of information. Apart from the fundamental characteristics of protein adsorption layers, i.e., surface tension and surface excess, the nanoscale structure of such layers and the interfacial protein conformations and morphologies are of pivotal importance for extending the depth of understanding on the topic. In this review article, we provide an extensive overview of the application of three methods, namely, ellipsometry, X-ray reflectometry and neutron reflectometry, for adsorption and structural studies on proteins at water/air and water/oil interfaces. The main attention is placed on the development of experimental approaches and on a discussion of the relevant achievements in terms of notable experimental results. We have attempted to cover the whole history of protein studies with these techniques, and thus, we believe the review should serve as a valuable reference to fuel ideas for a wide spectrum of researchers in different scientific fields where proteins at soft interface may be of relevance.
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Affiliation(s)
- Georgi G Gochev
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland; Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
| | - Richard A Campbell
- Division of Pharmacy and Optometry, University of Manchester, M13 9PT Manchester, UK
| | - Emanuel Schneck
- Physics Department, Technical University Darmstadt, 64289 Darmstadt, Germany
| | - Jan Zawala
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland
| | - Piotr Warszynski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30239 Krakow, Poland
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2
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Zhang T, Tang Y, Ge H, Zhang D, Li T, Cheng D, Liu J, Yu Y. Storage impact on egg white powder's physical and functional properties. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2023; 103:3799-3811. [PMID: 36251338 DOI: 10.1002/jsfa.12274] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/22/2022] [Accepted: 10/15/2022] [Indexed: 05/03/2023]
Abstract
BACKGROUND Changes in storage temperature and time alter the functional properties of egg white powder (EWP) and determine its quality and shelf-life, finally affecting the consumer acceptance of the products made from EWP. In the present study, the EWP samples were stored at four different temperatures (-20, 4, 25 and 37 °C) for 60 days, and then the protein structural, physical and functional properties of EWP were measured and assessed further for correlation with storage conditions using heatmap. RESULTS The viscosity of the EWP solution increased after 30 days. Foaming ability and rheological properties increased first and then decreased compared to untreated samples with the prolonged storage time. Correlation analysis results indicated that the gel hardness, water holding capacity, foaming ability, emulsifying ability, particle size, dispersibility and viscosity of EWP were significantly related to storage time (P < 0.05). Only the gelation properties of EWP stored at 37 °C for 60 days changed significantly and were negatively related to its moisture content (P < 0.05). Additionally, the random coil content of EWP was positively correlated with particle size, moisture content, solubility and gel properties, whereas β-sheet was negatively correlated with them. CONCLUSION Compared to other temperatures, the functional properties of EWP were relatively stable under 4 °C. Therefore, the low temperature (4 °C) was selected as the most suitable storage temperature for EWP. The results of the present study could provide a theoretical basis for the shelf-life extension of EWP. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Ting Zhang
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Yuanhu Tang
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Huifang Ge
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Deju Zhang
- Food and Nutritional Science, School of Biological Science, The University of Hong Kong, Hong Kong, China
| | - Ting Li
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Dongkun Cheng
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Jingbo Liu
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
| | - Yiding Yu
- Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun, China
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3
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Insight into binding mechanism between three whey proteins and mogroside V by multi-spectroscopic and silico methods: Impacts on structure and foaming properties. Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2022.108207] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Wierenga PA, Basheva ES, Delahaije RJBM. Variations in foam collapse and thin film stability with constant interfacial and bulk properties. Adv Colloid Interface Sci 2023; 312:102845. [PMID: 36709573 DOI: 10.1016/j.cis.2023.102845] [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: 11/28/2022] [Revised: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023]
Abstract
The stability of foams is commonly linked to the interfacial properties of the proteins and other surfactants used. This study aimed to use these relationships to explain differences in foam stability observed among similar beer samples from different breweries. The foam stability was different for each sample (Nibem foam stability ranged from 206 to 300 s), but ranking was similar for all three foaming methods used, thus independent of the method, gas, etc. Differences in foam stability were dominated by differences in coalescence, as illustrated by the correlation with the stability of single bubbles and thin liquid films. The differences in coalescence stability could not be explained by the measured interfacial properties (e.g. surface pressure, adsorption rate, dilatational modulus and surface shear viscosity), or the bulk properties (concentration, pH, ionic strength, viscosity), since they were similar for all samples. The drainage rates and disjoining pressure isotherms measured in thin liquid films were also similar for all samples, further limiting the options to explain the differences in foam stability using known arguments. The differences in coalescence stability of the thin films was shown to depend on the liquid in between the adsorbed layers of the thin film, using a modified capillary cell to exchange this liquid (to a buffer, or one of the other samples). This illustrates the need to review our current understanding and to develop new methods both for experimental study and theoretical description, to better understand foam stability in the future.
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Affiliation(s)
- Peter Alexander Wierenga
- Laboratory of Food Chemistry, Wageningen UR, Bornse Weilanden 9, Wageningen 6708, WG, the Netherlands.
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5
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Rafe A, Selahbarzin S, Kulozik U, Hesarinejad MA. Dilatational rheology-property relationships of β-lactoglobulin /high methoxyl pectin mixtures in aqueous foams. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Adsorption, Surface Viscoelasticity, and Foaming Properties of Silk Fibroin at the Air/Water Interface. COLLOIDS AND INTERFACES 2022. [DOI: 10.3390/colloids6030040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Like other proteins, the natural silk fibroin (SF) extracted from domesticated silkworms can adsorb at the air/water interface and stabilize foam due to its amphiphilic character and surface activity. At the interface, the adsorbed SF molecules experience structural reorganization and form water-insoluble viscoelastic films, which protect foam bubbles from coalescence and rupture. The solution conditions, such as protein concentration, pH, and additives, have significant influences on the molecular adsorption, layer thickness, interfacial mechanical strength, and, thus, on the foaming properties of SF. The understanding of the relationship between the interfacial adsorption, surface viscoelasticity, and foaming properties of SF is very important for the design, preparation, and application of SF foams in different fields.
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Rafe A, Glikman D, Rey NG, Haller N, Kulozik U, Braunschweig B. Structure-property relations of β-lactoglobulin/κ-carrageenan mixtures in aqueous foam. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128267] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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8
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Delahaije RJBM, Wierenga PA. Hydrophobicity Enhances the Formation of Protein-Stabilized Foams. Molecules 2022; 27:2358. [PMID: 35408752 PMCID: PMC9000900 DOI: 10.3390/molecules27072358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 04/04/2022] [Indexed: 11/24/2022] Open
Abstract
Screening proteins for their potential use in foam applications is very laborious and time consuming. It would be beneficial if the foam properties could be predicted based on their molecular properties, but this is currently not possible. For protein-stabilized emulsions, a model was recently introduced to predict the emulsion properties from the protein molecular properties. Since the fundamental mechanisms for foam and emulsion formation are very similar, it is of interest to determine whether the link to molecular properties defined in that model is also applicable to foams. This study aims to link the exposed hydrophobicity with the foam ability and foam stability, using lysozyme variants with altered hydrophobicity, obtained from controlled heat treatment (77 °C for 0-120 min). To establish this link, the molecular characteristics, interfacial properties, and foam ability and stability (at different concentrations) were analysed. The increasing hydrophobicity resulted in an increased adsorption rate constant, and for concentrations in the protein-poor regime, the increasing hydrophobicity enhanced foam ability (i.e., interfacial area created). At higher relative exposed hydrophobicity (i.e., ~2-5 times higher than native lysozyme), the adsorption rate constant and foam ability became independent of hydrophobicity. The foam stability (i.e., foam collapse) was affected by the initial foam structure. In the protein-rich regime-with nearly identical foam structure-the hydrophobicity did not affect the foam stability. The link between exposed hydrophobicity and foam ability confirms the similarity between protein-stabilized foams and emulsions, and thereby indicates that the model proposed for emulsions can be used to predict foam properties in the future.
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Affiliation(s)
| | - Peter A. Wierenga
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands;
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9
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Momen S, Alavi F, Aider M. Impact of alkaline electro-activation treatment on physicochemical and functional properties of sweet whey. Food Chem 2022; 373:131428. [PMID: 34710696 DOI: 10.1016/j.foodchem.2021.131428] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/06/2021] [Accepted: 10/17/2021] [Indexed: 12/22/2022]
Abstract
The impact of alkaline electro-activation (EA) on the protein solubility, foaming, and emulsifying characteristics of whey was investigated. EA caused protein aggregation and conjugation. At low electric current and holding time, proteins aggregation through disulfide bonds was observed, whereas increasing currents and holding times caused proteins to conjugate with sugars such as lactose, lactulose and galactose. The EA process improved the protein solubility at the pH range of 4.0-7.0. Compared to untreated whey, which produced micron-sized and unstable emulsions at pH 3, whey samples treated under 750 mA and 24-48 h holding time formed nano-sized and stable emulsions at this pH. Furthermore, although both untreated and EA-whey produced stable emulsions at pH 7, those emulsions prepared with EA-whey had smaller particle size and were more stable against droplet flocculation. EA-treated whey tended to generate foams with significantly higher overrun and stability. The present study demonstrated that EA can enhance the functionality of whey.
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Affiliation(s)
- Shima Momen
- Department of Food Sciences, Université Laval, Quebec, QC G1V 0A6, Canada; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC G1V 0A6, Canada
| | - Farhad Alavi
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588-6205, United States
| | - Mohammed Aider
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, QC G1V 0A6, Canada; Department of Soil Sciences and Agri-Food Engineering, Université Laval, Quebec, QC G1V 0A6, Canada.
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10
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Wei F, Lu M, Li J, Xiao J, Rogers MA, Cao Y, Lan Y. Construction of foam-templated oleogels based on rice bran protein. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107245] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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11
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Interfacial properties of milk proteins: A review. Adv Colloid Interface Sci 2021; 295:102347. [PMID: 33541692 DOI: 10.1016/j.cis.2020.102347] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/22/2022]
Abstract
The interfacial properties of dairy proteins are of great interest to the food industry. Food manufacturing involves various environmental conditions and multiple processes that significantly alter the structure and colloidal stability of food materials. The effects of concentration, pH, heat treatment, addition of salts etc., have considerable influence on the surface activity of proteins and the mechanical properties of the interfacial protein films. Studies to date have established some understanding of the links between environmental and processing related parameters and their impacts on interfacial behavior. Improvement in knowledge may allow better design of interfacial protein structures for different food applications. This review examines the effects of environmental and processing conditions on the interfacial properties of dairy proteins with emphasis on interfacial tension dynamics, dilatational and surface shear rheological properties. The most commonly used surface analytical techniques along with relevant methods are also addressed.
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12
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Dynamic adsorption and interfacial rheology of whey protein isolate at oil-water interfaces: Effects of protein concentration, pH and heat treatment. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.106640] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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13
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Effect of ultrasound-assisted alkaline treatment on functional property modifications of faba bean protein. Food Chem 2021; 354:129494. [PMID: 33743450 DOI: 10.1016/j.foodchem.2021.129494] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 01/06/2023]
Abstract
This study investigated alkaline shifting, ultrasonication, and their combination on functional modifications of faba bean protein isolate (FPI). The protein characterization revealed that the combined alkaline shifting/ultrasound treatment dissociated large aggregates of FPI into small ones, resulting in increased protein surface hydrophobicity and decreased free sulfhydryl groups. Such structural changes significantly increased FPI solubility from 12.2 to 40.4% to more than 95% at pH 3 and 7 and more than 80% at pH 6. Furthermore, the FPI modified by the combined alkaline shifting/ultrasound treatment produced emulsions with smaller particle size and superior stability at pH values 3 and 7. Likewise, a striking enhancement in foaming capacity (from 93% to 306-386%) and stability (from 10 s to 473-974 s) was achieved by the combined treatment. This study suggested that the ultrasound-assisted alkaline shifting treatment could be considered an effective method for improving FPI functional properties.
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14
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β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 5. Adsorption Isotherm and Equation of State Revisited, Impact of pH. COLLOIDS AND INTERFACES 2021. [DOI: 10.3390/colloids5010014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The theoretical description of the adsorption of proteins at liquid/fluid interfaces suffers from the inapplicability of classical formalisms, which soundly calls for the development of more complicated adsorption models. A Frumkin-type thermodynamic 2-d solution model that accounts for nonidealities of interface enthalpy and entropy was proposed about two decades ago and has been continuously developed in the course of comparisons with experimental data. In a previous paper we investigated the adsorption of the globular protein β-lactoglobulin at the water/air interface and used such a model to analyze the experimental isotherms of the surface pressure, Π(c), and the frequency-, f-, dependent surface dilational viscoelasticity modulus, E(c)f, in a wide range of protein concentrations, c, and at pH 7. However, the best fit between theory and experiment proposed in that paper appeared incompatible with new data on the surface excess, Γ, obtained from direct measurements with neutron reflectometry. Therefore, in this work, the same model is simultaneously applied to a larger set of experimental dependences, e.g., Π(c), Γ(c), E(Π)f, etc., with E-values measured strictly in the linear viscoelasticity regime. Despite this ambitious complication, a best global fit was elaborated using a single set of parameter values, which well describes all experimental dependencies, thus corroborating the validity of the chosen thermodynamic model. Furthermore, we applied the model in the same manner to experimental results obtained at pH 3 and pH 5 in order to explain the well-pronounced effect of pH on the interfacial behavior of β-lactoglobulin. The results revealed that the propensity of β-lactoglobulin globules to unfold upon adsorption and stretch at the interface decreases in the order pH 3 > pH 7 > pH 5, i.e., with decreasing protein net charge. Finally, we discuss advantages and limitations in the current state of the model.
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15
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Alavi F, Chen L, Wang Z, Emam-Djomeh Z. Consequences of heating under alkaline pH alone or in the presence of maltodextrin on solubility, emulsifying and foaming properties of faba bean protein. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106335] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Völp AR, Kagerbauer L, Engmann J, Gunes DZ, Gehin-Delval C, Willenbacher N. In-situ rheological and structural characterization of milk foams in a commercial foaming device. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2020.110150] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Braun L, Kühnhammer M, von Klitzing R. Stability of aqueous foam films and foams containing polymers: Discrepancies between different length scales. Curr Opin Colloid Interface Sci 2020. [DOI: 10.1016/j.cocis.2020.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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19
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β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 4. Impact on the Stability of Foam Films and Foams. MINERALS 2020. [DOI: 10.3390/min10070636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The complexity and high sensitivity of proteins to environmental factors give rise to a multitude of variables, which affect the stabilization mechanisms in protein foams. Interfacial and foaming properties of proteins have been widely studied, but the reported unique effect of pH, which can be of great interest to applications, has been investigated to a lesser extent. In this paper, we focus on the impact of pH on the stability of black foam films and corresponding foams obtained from solutions of a model globular protein—the whey β-lactoglobulin (BLG). Foam stability was analyzed utilizing three characteristic parameters (deviation time, transition time and half-lifetime) for monitoring the foam decay, while foam film stability was measured in terms of the critical disjoining pressure of film rupture. We attempt to explain correlations between the macroscopic properties of a foam system and those of its major building blocks (foam films and interfaces), and thus, to identify structure-property relationships in foam. Good correlations were found between the stabilities of black foam films and foams, while relations to the properties of adsorption layers appeared to be intricate. That is because pH-dependent interfacial properties of proteins usually exhibit an extremum around the isoelectric point (pI), but the stability of BLG foam films increases with increasing pH (3–7), which is well reflected in the foam stability. We discuss the possible reasons behind these intriguingly different behaviors on the basis of pH-induced changes in the molecular properties of BLG, which seem to be determining the mechanism of film rupture at the critical disjoining pressure.
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20
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Qiao X, Miller R, Schneck E, Sun K. Influence of pH on the surface and foaming properties of aqueous silk fibroin solutions. SOFT MATTER 2020; 16:3695-3704. [PMID: 32227052 DOI: 10.1039/c9sm02372k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Silk fibroin (SF) adsorbs at the air/water interface, reduces the surface tension, and forms interfacial layers suppressing bubble coalescence and stabilizing foam. Variation of pH alters the inter-molecular interactions of SF in the interfacial layers and thus interfacial network formation, dilatational visco-elasticity and foaming properties. At pH 4, around the isoelectric point, the reduced electrostatic repulsion between the SF molecules results in thicker adsorbed layers, but adsorption rate, foaming rate and foam stability are lower than at pH 3 and pH 7. At the highest pH investigated (pH 7), the small aggregate size and high protein flexibility lead to the formation of more ordered and stable viscoelastic interfacial networks, which are resistant to deformation breakage and generate homogeneous, denser and more stable foams.
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Affiliation(s)
- Xiuying Qiao
- State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Reinhard Miller
- Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Emanuel Schneck
- Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Kang Sun
- State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China.
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Abstract
AbstractMicroalgae are considered to be a promising alternative protein source after extraction and fractionation. Studies have shown that the insoluble protein fraction possesses interfacial activity and is able to stabilize oil-in-water emulsions after acid hydrolysis. The current work studied the surface pressure and foaming properties of the insoluble microalgae protein fraction obtained from Chlorella protothecoides and two of their hydrolysates. Results showed that the surface pressure of the three used protein fractions increased with increasing protein concentration. Moreover, surface pressure of the insoluble microalgae protein increased after hydrolysis at 65 °C (Hydrolysates 65) or 85 °C (Hydrolysates 85) suggesting an increased foaming capacity of the insoluble microalgae protein fraction after hydrolysis. Hydrolysates 85 had the highest foam capacity, and foams remained stable with a half-life time of over 5 h. Overall, hydrolysis of the insoluble microalgae protein fraction with 0.5 M HCl at 85 °C for 4 h resulted in generation of protein fragments that appear to be very suitable to stabilize air-water interfaces in foam-based foods.
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22
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Gochev GG, Scoppola E, Campbell RA, Noskov BA, Miller R, Schneck E. β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 3. Neutron Reflectometry Study on the Effect of pH. J Phys Chem B 2019; 123:10877-10889. [PMID: 31725291 DOI: 10.1021/acs.jpcb.9b07733] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Several characteristics of β-lactoglobulin (BLG) layers adsorbed at the air/water interface exhibit a strong pH dependence, but our knowledge on the underlying structure-property relations is still fragmental. Here, we therefore extend our recent studies by neutron reflectometry (NR) and provide a comprehensive overview through direct measurements of the surface excess Γ and the layers' molecular structure. This enables comparison with available literature data to draw general conclusions. The NR experiments were performed at various pH values and within a wide range of protein concentrations, CBLG. Adsorption kinetics measurements in air-contrast-matched-water and over a narrow Qz range enabled direct quantification of the dynamic surface excess Γ(t) and are found to be consistent with ellipsometry data. Near the isoelectric point, pI, the rates of adsorption and Γ are maximal but only at sufficiently high CBLG. NR data collected over a wider Qz range and in two aqueous isotopic contrasts revealed the structure of adsorbed BLG layers at a steady state close to equilibrium. Independent of the pH, BLG was found to form dense monolayers with average thicknesses of 1.1 nm, suggesting flattening of the BLG globules upon adsorption as compared with their bulk dimensions (≈3.5 nm). Near pI and at sufficiently high CBLG, a thick (≈5.5 nm) but looser secondary sublayer is additionally formed adjacent to the dense primary monolayer. The thickness of this sublayer can be interpreted in terms of disordered BLG dimers. The results obtained and notably the specific interfacial structuring of BLG near pI complement previous observations relating the impact of solution pH and CBLG on other interfacial characteristics such as surface pressure and surface dilational viscoelasticity modulus.
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Affiliation(s)
- Georgi G Gochev
- Max Planck Institute of Colloids and Interfaces , 14476 Potsdam , Germany.,Institute of Physical Chemistry , Bulgarian Academy of Sciences , 1113 Sofia , Bulgaria
| | - Ernesto Scoppola
- Max Planck Institute of Colloids and Interfaces , 14476 Potsdam , Germany
| | - Richard A Campbell
- Institut Laue-Langevin , 71 Avenue des Martyrs, CS20156 , 38042 Grenoble , France.,Division of Pharmacy and Optometry , University of Manchester , M13 9PT Manchester , U.K
| | - Boris A Noskov
- Institute of Chemistry , St. Petersburg State University , 198504 Saint-Petersburg , Russia
| | - Reinhard Miller
- Max Planck Institute of Colloids and Interfaces , 14476 Potsdam , Germany
| | - Emanuel Schneck
- Max Planck Institute of Colloids and Interfaces , 14476 Potsdam , Germany
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23
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Bois R, Hecke E, Pezron I, Nesterenko A. Screening of Surfactant Foaming Properties Using the Gas‐Sparging Method: Design of an Optimal Protocol. J SURFACTANTS DETERG 2019. [DOI: 10.1002/jsde.12376] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Rémy Bois
- Sorbonne UniversitésUniversité de Technologie de Compiègne, ESCOM, EA 4297 TIMR, rue du Dr Schweitzer 60200 Compiègne France
| | - Elisabeth Hecke
- Sorbonne UniversitésUniversité de Technologie de Compiègne, ESCOM, EA 4297 TIMR, rue du Dr Schweitzer 60200 Compiègne France
| | - Isabelle Pezron
- Sorbonne UniversitésUniversité de Technologie de Compiègne, ESCOM, EA 4297 TIMR, rue du Dr Schweitzer 60200 Compiègne France
| | - Alla Nesterenko
- Sorbonne UniversitésUniversité de Technologie de Compiègne, ESCOM, EA 4297 TIMR, rue du Dr Schweitzer 60200 Compiègne France
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Delahaije RJ, Lech FJ, Wierenga PA. Investigating the effect of temperature on the formation and stabilization of ovalbumin foams. Food Hydrocoll 2019. [DOI: 10.1016/j.foodhyd.2019.01.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Narsimhan G, Xiang N. Role of Proteins on Formation, Drainage, and Stability of Liquid Food Foams. Annu Rev Food Sci Technol 2017; 9:45-63. [PMID: 29272186 DOI: 10.1146/annurev-food-030216-030009] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Foam is a high-volume fraction dispersion of gas into a liquid or a solid. It is important to understand the effect of formulation on shelf life and texture of food foams. The objective of this review is to elucidate mechanisms of formation and stability of foams and relate them to the formulations. Emulsifiers are important in foam formation, whereas proteins are generally preferred to provide long-term stability. Syneresis in foams is a precursor to their collapse in many instances. Intermolecular forces, conformation, and flexibility of proteins play an important role in foam stabilization. An adsorbed protein layer at air/water interfaces imparts interfacial rheology that is necessary to improve the shelf life of foam products. Wettability and spreading of food particles at the interface can stabilize or destabilize foams, depending on their properties. More studies are needed to fully understand the complex interplay of various mechanisms of destabilization in a real-food formulation.
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Affiliation(s)
- Ganesan Narsimhan
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Ning Xiang
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana 47907, USA;
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Gálvez-Ruiz MJ. Different approaches to study protein films at air/water interface. Adv Colloid Interface Sci 2017; 247:533-542. [PMID: 28734347 DOI: 10.1016/j.cis.2017.07.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/13/2017] [Accepted: 07/13/2017] [Indexed: 01/01/2023]
Abstract
In this review classical studies on insoluble liquid monolayers formed by proteins are examined and compared. It has been focused the attention on the information that it is possible to obtain from the π-a isotherms recorded by compression of the monolayers. In recent decades new techniques have developed, mainly microscopy, that provide valuable information on the behavior and structure of fluid films. However, frequently the data are difficult to interpret and require a previous thermodynamic study of them on the basis of the surface tension (or surface pressure) as a function of the molecular area measurement. The main aim of this paper is to underline that surface balance type of Langmuir is a powerful technique since it enables to obtain information at molecular level from a macroscopic analysis. Notably, this information is revealed very interesting when it comes to studying protein films. From this point of view it has been reviewed the study methods and results for four proteins.
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27
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Relative contributions of charge and surface coverage on pH-induced flocculation of protein-stabilized emulsions. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.10.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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28
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Dombrowski J, Gschwendtner M, Kulozik U. Evaluation of structural characteristics determining surface and foaming properties of β-lactoglobulin aggregates. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.12.045] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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29
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Characterization and emulsifying properties of β-lactoglobulin-gum Acacia Seyal conjugates prepared via the Maillard reaction. Food Chem 2017; 214:614-621. [DOI: 10.1016/j.foodchem.2016.07.112] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/19/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022]
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