1
|
Napieraj M, Lutton E, Perez J, Boué F, Brûlet A. Destructuration of Canola Protein Gels during In Situ Gastrointestinal Digestion Studied by X-ray Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:16226-16238. [PMID: 39041952 DOI: 10.1021/acs.langmuir.4c01341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
We are studying the destructuration of canola protein gels, as a solid food model, during in situ gastrointestinal digestion using synchrotron small-angle X-ray scattering (SAXS). Digestion of two gels, prepared by heating pH 8 and pH 11 solutions, was carried out by diffusion of enzymatic juices into the gel from the top of the capillary and monitored for several tens of hours. Very similar time evolutions of SAXS curves occur at different positions of the gel in the capillary, with a delay determined by the distance from the surface initially in contact with the digestive juice. The main phenomena observed are (i) at the scale of the protein conformation (1-5 nm). The scattering curve is a power law, the exponent of which measures the compactness (related to the degree of unfolding). It can be plotted as a function of the characteristic size of proteins/and interprotein distances and as a function of the scattering intensity. Such diagrams clearly show successive digestion processes. For the pH 11 gel, in which proteins are initially hardly unfolded, the digestive processes are unfolding (1st step), recompaction-aggregation phenomena (2nd step) due to gastrointestinal pH conditions and enzymatic cleavage, further unfolding-disaggregation (3rd step), and final protein cleavage (4th step) down to small peptides. For the pH 8 gel, proteins are initially unfolded, and only the last three steps are observed, showing the influence of easier access for the enzymes. (ii) At the scale of large aggregates (10-50 nm), we observe for both gels a decrease in the size and/or number of these aggregates during digestion and alteration of their interfaces. (iii) At the scale of the secondary protein structure, wide-angle X-ray scattering is very useful for detecting the degradation of the secondary protein structure at different steps of digestion.
Collapse
Affiliation(s)
- Maja Napieraj
- Laboratoire Léon Brillouin, UMR12 CEA-CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif sur Yvette, France
| | - Evelyne Lutton
- Mathématiques et Informatique Appliquée─Paris, UMR518 AgroParisTech-INRAE, Université Paris-Saclay, 91120 Palaiseau, France
- Institut des Systèmes Complexes, 75013 Paris, France
| | - Javier Perez
- SWING, Synchrotron SOLEIL, Saint-Aubin - BP 48, 91192 Gif sur Yvette, France
| | - François Boué
- Laboratoire Léon Brillouin, UMR12 CEA-CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif sur Yvette, France
| | - Annie Brûlet
- Laboratoire Léon Brillouin, UMR12 CEA-CNRS, Université Paris-Saclay, CEA Saclay, F-91191 Gif sur Yvette, France
| |
Collapse
|
2
|
Gul O, Gul LB, Baskıncı T, Parlak ME, Saricaoglu FT. Influence of pH and ionic strength on the bulk and interfacial rheology and technofunctional properties of hazelnut meal protein isolate. Food Res Int 2023; 169:112906. [PMID: 37254341 DOI: 10.1016/j.foodres.2023.112906] [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: 01/25/2023] [Revised: 04/05/2023] [Accepted: 04/24/2023] [Indexed: 06/01/2023]
Abstract
The functional, bulk, and interfacial shear rheological properties of hazelnut protein isolate were studied at different pH values between 3.0 and 8.0 and ionic strength levels between 0.0 and 1.0 M. The results showed that pH significantly affected protein solubility, emulsion properties, water and oil holding capacities, foam stability, surface hydrophobicity, and free -SH groups. The highest surface hydrophobicity, free -SH groups, and better functional properties were observed at pH 8.0. Protein solubility also increased with increasing ionic strength up to 0.6 M. The emulsion and foam stability of hazelnut protein isolate showed similar changes with protein solubility. The flow behavior of hazelnut protein suspensions was found to be shear thinning with the highest consistency index at pH 3.0 and the lowest at pH 6.0, however, the ionic strength did not significantly affect the consistency coefficient but did cause a significant change in the flow behavior index, with the lowest value observed at 0.6 M. The best gel structure in hazelnut proteins was observed at pH 3.0 and 4.0. The addition of ions at 0.4 and 0.6 M concentrations resulted in an improved viscoelastic character. The hazelnut protein isolate was also found to form solid-like viscoelastic layers at both air-water and oil-water interfaces, with the interfacial adsorption behavior affected by both pH and ionic strength. Overall, these results suggest that pH and ionic strength have significant effects on the functional and rheological properties of hazelnut protein isolate, which may have the potential as an auxiliary substance in food systems.
Collapse
Affiliation(s)
- Osman Gul
- Department of Food Engineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey
| | - Latife Betul Gul
- Department of Food Engineering, Faculty of Engineering, Giresun University, Giresun, Turkey.
| | - Tugba Baskıncı
- Department of Food Engineering, Faculty of Engineering and Architecture, Kastamonu University, Kastamonu, Turkey
| | - Mahmut Ekrem Parlak
- Department of Food Engineering, Faculty of Engineering and Natural Sciences, Bursa Technical University, Bursa, Turkey
| | - Furkan Turker Saricaoglu
- Department of Food Engineering, Faculty of Engineering and Natural Sciences, Bursa Technical University, Bursa, Turkey
| |
Collapse
|
3
|
Shen X, Zheng H, Han M, Xu X, Li B, Guo Q. Intermolecular forces regulate in-vitro digestion of whey protein emulsion gels: Towards controlled lipid release. J Colloid Interface Sci 2023; 649:245-254. [PMID: 37348344 DOI: 10.1016/j.jcis.2023.06.023] [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: 03/22/2023] [Revised: 05/12/2023] [Accepted: 06/05/2023] [Indexed: 06/24/2023]
Abstract
HYPOTHESIS The utilization of emulsion-filled protein hydrogels for controlled lipid release in the gastrointestinal tract (GIT) displays great potential in drug delivery and obesity treatment. However, how intermolecular interactions among protein molecules influence lipid digestion of the gels is still understudied. EXPERIMENTS Differently structured whey protein emulsion gels were fabricated by heating emulsions with blocking of disulfide bonds (the "noncovalent" gel), noncovalent interactions (the "disulfide" gel), or neither of these (the "control" gel). The intermolecular interactions-gel structure-lipid digestion relationship was investigated by characterizing structural/mechanical properties of the gels and monitoring their dynamic breakdown in a simulated GIT. FINDINGS Although the disulfide-crosslinked protein network formed thick interfacial layers around oil droplets and resisted intestinal proteolysis, the "disulfide" gel had the fastest lipolysis rate, indicating that it could not inhibit the access of lipases to oil droplets. In contrast, the "noncovalent" gel was more susceptible to in-vitro digestion than the "control" gel because of lower gel strength, resulting in a faster lipolysis rate. This demonstrated that intermolecular disulfide bonds and noncovalent interactions played distinctive roles in the digestion of the gels; they represented the structural backbone and the infill in the gel structure, respectively.
Collapse
Affiliation(s)
- Xingxing Shen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China; Maanshan Safety Inspection Center for Food and Drug, Maanshan Administration for Market Regulation, Maanshan 243000, China
| | - Hao Zheng
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China
| | - Menghan Han
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China
| | - Xiyu Xu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China
| | - Bingyi Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China
| | - Qing Guo
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, China Agricultural University, Beijing 100083, China; Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture and Rural Affairs, Beijing, China; Beijing Key Laboratory of Food Non-Thermal Processing, Beijing 100083, China.
| |
Collapse
|
4
|
Andlinger DJ, Kulozik U. Protein-protein interactions explain the temperature-dependent viscoelastic changes occurring in colloidal protein gels. SOFT MATTER 2023; 19:1144-1151. [PMID: 36607604 DOI: 10.1039/d2sm01092e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Denaturation of protein solutions can be induced by higher temperatures and the presence of non-polar organic solutions. The denatured proteins form aggregates and gels through protein interactions occurring between their amino acid side chains. Depending on the involved side chains, the denaturation conditions lead to different gel properties. As model systems, a variety of food proteins were gelled through different mechanisms to cover a whole range of protein-protein interactions. Especially the temperature dependence of the viscoelastic properties in a simple rheometer method was found to be very different. These differences could be explained by the different thermodynamic properties of the involved protein-protein interactions. Electrostatic interactions were shown to weaken the resulting gel upon temperature increase whereas entropically driven interactions such as hydrophobic or covalent links were strengthened with increased temperatures. A proposed model explaining these results can be used to assess protein interactions in hydrogels in a non-invasive way and could also have applications to describe the temperature behavior of other hydrogels.
Collapse
Affiliation(s)
- David J Andlinger
- Chair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, Weihenstephaner Berg 1, 85354, Freising, Germany.
| | - Ulrich Kulozik
- Chair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, Weihenstephaner Berg 1, 85354, Freising, Germany.
| |
Collapse
|
5
|
Chen D, Kuzmenko I, Ilavsky J, Pinho L, Campanella O. Structural evolution during gelation of pea and whey proteins envisaged by time-resolved ultra-small-angle x-ray scattering (USAXS). Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
6
|
Hundschell CS, Brühan J, Anzmann T, Kohlus R, Wagemans AM. Influence of Levan on the Thermally Induced Gel Formation of β-Lactoglobulin. Gels 2022; 8:gels8040228. [PMID: 35448130 PMCID: PMC9029924 DOI: 10.3390/gels8040228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 12/04/2022] Open
Abstract
In this study, the influence of levan on the phase behavior and the thermally induced gelation of the mixed β-lactoglobulin—levan gels as a function of polymer content, molecular weight and ionic strength was characterized. For this purpose, rheology was used to study the mechanical properties of the gels and the water binding of the network structure was investigated by time domain nuclear magnetic resonance. Phase behavior and network type were analyzed by optical observation and electron microscopy. Levan enhanced the aggregation and gel formation of β-lg due to segregative forces between the polymer species. Segregation was caused by the excluded volume effect and was more pronounced at lower ionic strength, higher levan contents and higher levan molecular weights. The presence of levan increased the water binding of the gel networks. However, this effect decreased with increasing levan content. At high ionic strength and high levan content, phase separated gels were formed. While segregative forces enhanced network formation, and therefore, increased the gel strength of mixed gels at low ionic strength, levan had also antagonistic effects on the network formation at high ionic strength and high polymer contents.
Collapse
Affiliation(s)
- Christoph S. Hundschell
- Department of Food Colloids, Institute of Food Technology and Food Chemistry, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
- Correspondence: (C.S.H.); (A.M.W.)
| | - Juliane Brühan
- Department of Food Colloids, Institute of Food Technology and Food Chemistry, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
| | - Theresa Anzmann
- Department of Process Engineering and Food Powders, University of Hohenheim, Garbenstraße 25, 70599 Stuttgart, Germany; (T.A.); (R.K.)
| | - Reinhard Kohlus
- Department of Process Engineering and Food Powders, University of Hohenheim, Garbenstraße 25, 70599 Stuttgart, Germany; (T.A.); (R.K.)
| | - Anja M. Wagemans
- Department of Food Colloids, Institute of Food Technology and Food Chemistry, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
- Correspondence: (C.S.H.); (A.M.W.)
| |
Collapse
|
7
|
Yang Z, de Campo L, Gilbert EP, Knott R, Cheng L, Storer B, Lin X, Luo L, Patole S, Hemar Y. Effect of NaCl and CaCl2 concentration on the rheological and structural characteristics of thermally-induced quinoa protein gels. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107350] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
8
|
Role of Flaxseed Gum and Whey Protein Microparticles in Formulating Low-Fat Model Mayonnaises. Foods 2022; 11:foods11030282. [PMID: 35159434 PMCID: PMC8834398 DOI: 10.3390/foods11030282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 01/07/2022] [Indexed: 12/19/2022] Open
Abstract
Flaxseed gum (FG) and whey protein microparticles (WPMs) were used to substitute fats in model mayonnaises. WPMs were prepared by grinding the heat-set whey protein gel containing 10 mM CaCl2 into small particles (10–20 µm). Then, 3 × 4 low-fat model mayonnaises were prepared by varying FG (0.3, 0.6, 0.9 wt%) and WPM (0, 8, 16, 24 wt%) concentrations. The effect of the addition of FG and WPMs on rheology, instrumental texture and sensory texture and their correlations were investigated. The results showed that all samples exhibited shear thinning behavior and ‘weak gel’ properties. Although both FG and WPMs enhanced rheological (e.g., viscosity and storage modulus) and textural properties (e.g., hardness, consistency, adhesiveness, cohesiveness) and kinetic stability, this enhancement was dominated by FG. FG and WPMs affected bulk properties through different mechanisms, (i.e., active filler and entangled polysaccharide networks). Panellists evaluated sensory texture in three stages: extra-oral, intra-oral and after-feel. Likewise, FG dominated sensory texture of model mayonnaises. With increasing FG concentration, sensory scores for creaminess and mouth-coating increased, whereas those of firmness, fluidity and spreadability decreased. Creaminess had a linear negative correlation with firmness, fluidity and spreadability (R2 > 0.985), while it had a linear positive correlation with mouth-coating (R2 > 0.97). A linear positive correlation (R2 > 0.975) was established between creaminess and viscosity at different shear rates/instrumental texture parameters. This study highlights the synergistic role of FG and WPMs in developing low-fat mayonnaises.
Collapse
|
9
|
|
10
|
İnce Coşkun AE, Özdestan Ocak Ö. Foaming behavior of colloidal whey protein isolate micro-particle dispersions. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Lin J, Huang Y, Wang S. The Hofmeister effect on protein hydrogels with stranded and particulate microstructures. Colloids Surf B Biointerfaces 2020; 196:111332. [DOI: 10.1016/j.colsurfb.2020.111332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 08/13/2020] [Accepted: 08/16/2020] [Indexed: 10/23/2022]
|
12
|
Dominguez AV, Nicolai T. Heat induced gelation of micellar casein with and without whey proteins in the presence of polyphosphate. Int Dairy J 2020. [DOI: 10.1016/j.idairyj.2020.104640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
13
|
Liang X, Ma C, Yan X, Zeng H, McClements DJ, Liu X, Liu F. Structure, rheology and functionality of whey protein emulsion gels: Effects of double cross-linking with transglutaminase and calcium ions. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2019.105569] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
14
|
Nicolai T. Gelation of food protein-protein mixtures. Adv Colloid Interface Sci 2019; 270:147-164. [PMID: 31229885 DOI: 10.1016/j.cis.2019.06.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 06/09/2019] [Accepted: 06/09/2019] [Indexed: 01/04/2023]
Abstract
Gelation of proteins is one of the principal means to give desirable texture to food products. Gelation of individual proteins in aqueous solution has been investigated intensively in the past, but in most food products the system contains mixtures of different types of proteins. Therefore one needs to consider interaction between different proteins both before and during gelation. Most food proteins can be classified as globular proteins, but casein and gelatin are also important food proteins. In this review the focus is on gelation induced by heating or cooling, which is the most commonly used method. After briefly discussing general features of protein aggregation and gelation, the literature on gelation of mixtures of different types of globular proteins is reviewed as well as that of mixtures of globular proteins with gelatin or with casein. The effect on the gel stiffness and the microstructure of the gelled mixtures will be discussed in terms of different scenarios that can be envisaged: independent aggregation and gelation, co-aggregation and phase separation.
Collapse
Affiliation(s)
- Taco Nicolai
- IMMM UMR-CNRS 6283, Le Mans Université, 72085, Le Mans Cedex 9, France.
| |
Collapse
|
15
|
Jansens KJA, Rombouts I, Grootaert C, Brijs K, Van Camp J, Van der Meeren P, Rousseau F, Schymkowitz J, Delcour JA. Rational Design of Amyloid-Like Fibrillary Structures for Tailoring Food Protein Techno-Functionality and Their Potential Health Implications. Compr Rev Food Sci Food Saf 2018; 18:84-105. [PMID: 33337021 DOI: 10.1111/1541-4337.12404] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022]
Abstract
To control and enhance protein functionality is a major challenge for food scientists. In this context, research on food protein fibril formation, especially amyloid fibril formation, holds much promise. We here first provide a concise overview of conditions, which affect amyloid formation in food proteins. Particular attention is directed towards amyloid core regions because these sequences promote ordered aggregation. Better understanding of this process will be key to tailor the fibril formation process. Especially seeding, that is, adding preformed protein fibrils to protein solutions to accelerate fibril formation holds promise to tailor aggregation and fibril techno-functionality. Some studies have already indicated that food protein fibrillation indeed improves their techno-functionality. However, much more research is necessary to establish whether protein fibrils are useful in complex food systems and whether and to what extent they resist food processing unit operations. In this review the effect of amyloid formation on gelation, interfacial properties, foaming, and emulsification is discussed. Despite their prevalent role as functional structures, amyloids also receive a lot of attention due to their association with protein deposition diseases, prompting us to thoroughly investigate the potential health impact of amyloid-like aggregates in food. A literature review on the effect of the different stages of the human digestive process on amyloid toxicity leads us to conclude that food-derived amyloid fibrils (even those with potential pathogenic properties) very likely have minimal impact on human health. Nevertheless, prior to wide-spread application of the technology, it is highly advisable to further verify the lack of toxicity of food-derived amyloid fibrils.
Collapse
Affiliation(s)
- Koen J A Jansens
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Ine Rombouts
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Charlotte Grootaert
- Laboratory of Food Chemistry and Human Nutrition, Ghent Univ., Coupure Links 653, B-9000, Ghent, Belgium
| | - Kristof Brijs
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - John Van Camp
- Laboratory of Food Chemistry and Human Nutrition, Ghent Univ., Coupure Links 653, B-9000, Ghent, Belgium
| | - Paul Van der Meeren
- Particle and Interfacial Technology Group, Ghent Univ., Coupure Links 653, B- 9000, Ghent, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB, B-3000 Leuven, Belgium. Authors Rousseau and Schymkowitz are also with Dept. of Cellular and Molecular Medicine, KU Leuven, B-3000, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB, B-3000 Leuven, Belgium. Authors Rousseau and Schymkowitz are also with Dept. of Cellular and Molecular Medicine, KU Leuven, B-3000, Leuven, Belgium
| | - Jan A Delcour
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| |
Collapse
|
16
|
Chen N, Chassenieux C, Nicolai T. Kinetics of NaCl induced gelation of soy protein aggregates: Effects of temperature, aggregate size, and protein concentration. Food Hydrocoll 2018. [DOI: 10.1016/j.foodhyd.2017.09.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
17
|
Homer S, Lundin L, Dunstan DE. A detailed investigation of whey protein isolate solutions and gels reveals a number of novel characteristics. Food Hydrocoll 2018. [DOI: 10.1016/j.foodhyd.2017.10.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
18
|
Lee YR, Park D, Choi SK, Kim M, Baek HS, Nam J, Chung CB, Osuji CO, Kim JW. Smart Cellulose Nanofluids Produced by Tunable Hydrophobic Association of Polymer-Grafted Cellulose Nanocrystals. ACS APPLIED MATERIALS & INTERFACES 2017; 9:31095-31101. [PMID: 28816429 DOI: 10.1021/acsami.7b08783] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cellulose fibrils, unique plant-derived semicrystalline nanomaterials with exceptional mechanical properties, have significant potential for rheology modification of complex fluids due to their ability to form a physically associated semiflexible fibrillary network. Here, we report new associative cellulose nanocrystals (ACNCs) with stress-responsive rheological behaviors in an aqueous solution. The surface-mediated living radical polymerization was employed to graft poly(stearyl methacrylate-co-2-methacryloxyethyl phosphorylcholine) brushes onto the nanofibrils, and then 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation was conducted to produce nanoscale ACNCs in the aqueous solution. The ACNCs displayed interfibril association driven by the hydrophobic interaction that resulted in the formation of a nanofibrillar crystalline gel phase. We observed that the viscosity of the ACNC fluid showed reversible shear thinning and temperature-induced thickening in response to applied shear stress and thermal shock. Moreover, thanks to generation of a mechanically robust nanofibrillar crystalline gel network, the ACNC suspension showed extraordinary stability to changes in salinity and pH. These results highlighted that the interfibril hydrophobic association of ACNCs was vital and played an essential role in regulation of stimuli-responsive sol-gel transitions.
Collapse
Affiliation(s)
- Yea Ram Lee
- Department of Bionano Technology, Hanyang University , Ansan 15588, Republic of Korea
| | - Daehwan Park
- Department of Bionano Technology, Hanyang University , Ansan 15588, Republic of Korea
| | - Sang Koo Choi
- Department of Bionano Technology, Hanyang University , Ansan 15588, Republic of Korea
| | - Miju Kim
- Amore-Pacific R&D Centre , Yongin 17074, Republic of Korea
| | - Heung Soo Baek
- Amore-Pacific R&D Centre , Yongin 17074, Republic of Korea
| | - Jin Nam
- Amore-Pacific R&D Centre , Yongin 17074, Republic of Korea
| | - Chan Bok Chung
- SK Bioland R&D Co. Ltd. , Osong 28162, Republic of Korea
| | - Chinedum O Osuji
- Department of Chemical and Environmental Engineering, Yale University , New Haven, Connecticut 06511, United States
| | - Jin Woong Kim
- Department of Bionano Technology, Hanyang University , Ansan 15588, Republic of Korea
- Department of Chemical and Molecular Engineering, Hanyang University , Ansan 15588, Republic of Korea
| |
Collapse
|
19
|
Nguyen BT, Chassenieux C, Nicolai T, Schmitt C. Effect of the pH and NaCl on the microstructure and rheology of mixtures of whey protein isolate and casein micelles upon heating. Food Hydrocoll 2017. [DOI: 10.1016/j.foodhyd.2017.03.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
20
|
Chen N, Zhao M, Niepceron F, Nicolai T, Chassenieux C. The effect of the pH on thermal aggregation and gelation of soy proteins. Food Hydrocoll 2017. [DOI: 10.1016/j.foodhyd.2016.12.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
21
|
Lam CWY, Ikeda S. Physical Properties of Heat-induced Whey Protein Aggregates Formed at pH 5.5 and 7.0. FOOD SCIENCE AND TECHNOLOGY RESEARCH 2017. [DOI: 10.3136/fstr.23.595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Shinya Ikeda
- Department of Food Science, University of Wisconsin-Madison
| |
Collapse
|
22
|
Nguyen BT, Nicolai T, Chassenieux C, Schmitt C, Bovetto L. Heat-induced gelation of mixtures of whey protein isolate and sodium caseinate between pH 5.8 and pH 6.6. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2016.05.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
23
|
Nieuwland M, Bouwman WG, Pouvreau L, Martin AH, de Jongh HH. Relating water holding of ovalbumin gels to aggregate structure. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2015.06.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
24
|
Munialo CD, van der Linden E, Ako K, de Jongh HH. Quantitative analysis of the network structure that underlines the transitioning in mechanical responses of pea protein gels. Food Hydrocoll 2015. [DOI: 10.1016/j.foodhyd.2015.03.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
25
|
Delahaije RJBM, Wierenga PA, Giuseppin MLF, Gruppen H. Comparison of heat-induced aggregation of globular proteins. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:5257-5265. [PMID: 25965109 DOI: 10.1021/acs.jafc.5b00927] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Typically, heat-induced aggregation of proteins is studied using a single protein under various conditions (e.g., temperature). Because different studies use different conditions and methods, a mechanistic relationship between molecular properties and the aggregation behavior of proteins has not been identified. Therefore, this study investigates the kinetics of heat-induced aggregation and the size/density of formed aggregates for three different proteins (ovalbumin, β-lactoglobulin, and patatin) under various conditions (pH, ionic strength, concentration, and temperature). The aggregation rate of β-lactoglobulin was slower (>10 times) than that of ovalbumin and patatin. Moreover, the conditions (pH, ionic strength, and concentration) affected the aggregation kinetics of β-lactoglobulin more strongly than for ovalbumin and patatin. In contrast to the kinetics, for all proteins the aggregate size/density increased with decreasing electrostatic repulsion. By comparing these proteins under these conditions, it became clear that the aggregation behavior cannot easily be correlated to the molecular properties (e.g., charge and exposed hydrophobicity).
Collapse
Affiliation(s)
- Roy J B M Delahaije
- †Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Peter A Wierenga
- †Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | | | - Harry Gruppen
- †Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| |
Collapse
|
26
|
Sathaye S, Mbi A, Sonmez C, Chen Y, Blair DL, Schneider JP, Pochan DJ. Rheology of peptide- and protein-based physical hydrogels: Are everyday measurements just scratching the surface? WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 7:34-68. [DOI: 10.1002/wnan.1299] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/11/2014] [Accepted: 08/07/2014] [Indexed: 01/30/2023]
Affiliation(s)
- Sameer Sathaye
- Department of Materials Science and Engineering and Delaware Biotechnology Institute; University of Delaware; Newark DE USA
| | - Armstrong Mbi
- Department of Physics; Georgetown University; Washington DC USA
| | - Cem Sonmez
- Department of Chemistry; University of Delaware; Newark DE USA
- Chemical Biology Laboratory; National Cancer Institute, Frederick National Laboratory for Cancer Research; Frederick MD USA
| | - Yingchao Chen
- Department of Materials Science and Engineering and Delaware Biotechnology Institute; University of Delaware; Newark DE USA
| | - Daniel L. Blair
- Department of Physics; Georgetown University; Washington DC USA
| | - Joel P. Schneider
- Chemical Biology Laboratory; National Cancer Institute, Frederick National Laboratory for Cancer Research; Frederick MD USA
| | - Darrin J. Pochan
- Department of Materials Science and Engineering and Delaware Biotechnology Institute; University of Delaware; Newark DE USA
| |
Collapse
|
27
|
Phan-Xuan T, Durand D, Nicolai T, Donato L, Schmitt C, Bovetto L. Heat induced formation of beta-lactoglobulin microgels driven by addition of calcium ions. Food Hydrocoll 2014. [DOI: 10.1016/j.foodhyd.2012.09.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
28
|
Guo Q, Ye A, Lad M, Dalgleish D, Singh H. The breakdown properties of heat-set whey protein emulsion gels in the human mouth. Food Hydrocoll 2013. [DOI: 10.1016/j.foodhyd.2013.03.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
29
|
Nicolai T, Durand D. Controlled food protein aggregation for new functionality. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2013.03.001] [Citation(s) in RCA: 217] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
30
|
Kosters HA, Wierenga PA, de Vries R, Gruppen H. Protein-peptide interaction: study of heat-induced aggregation and gelation of β-lactoglobulin in the presence of two peptides from its own hydrolysate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:4218-4225. [PMID: 23586481 DOI: 10.1021/jf400612f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Two peptides, [f135-158] and [f135-162]-SH, were used to study the binding of the peptides to native β-lactolobulin, as well as the subsequent effects on aggregation and gelation of β-lactoglobulin. The binding of the peptide [f135-158] to β-lactoglobulin at room temperature was confirmed by SELDI-TOF-MS. It was further illustrated by increased turbidity of mixed solutions of peptide and protein (at pH 7), indicating association of proteins and peptides in larger complexes. At pH below the isoelectric point of the protein, the presence of peptides did not lead to an increased turbidity, showing the absence of complexation. The protein-peptide complexes formed at pH 7 were found to dissociate directly upon heating. After prolonged heating, extensive aggregation was observed, whereas no aggregation was seen for the pure protein or pure peptide solutions. The presence of the free sulfhydryl group in [f135-162]-SH resulted in a 10 times increase in the amount of aggregation of β-lactoglobulin upon heating, illustrating the additional effect of the free sulfhydryl group. Subsequent studies on the gel strength of heat-induced gels also showed a clear difference between these two peptides. The replacement of additional β-lactoglobulin by [f135-158] resulted in a decrease in gel strength, whereas replacement by peptide [f135-162]-SH increased gel strength.
Collapse
|
31
|
Balakrishnan G, Nicolai T, Durand D. Relation between the gel structure and the mobility of tracers in globular protein gels. J Colloid Interface Sci 2012; 388:293-9. [DOI: 10.1016/j.jcis.2012.08.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/13/2012] [Accepted: 08/14/2012] [Indexed: 11/17/2022]
|
32
|
Ikeda S, Zhong Q. Polymer and colloidal models describing structure-function relationships. Annu Rev Food Sci Technol 2012; 3:405-24. [PMID: 22136127 DOI: 10.1146/annurev-food-022811-101250] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Colloidal and polymer systems are not only abundant in food but also useful for gaining insights into structure-function relationships of food. Colloid and polymer systems are composed of mesoscopic scale particles dispersed in a liquid. Because of a relatively small potential barrier against aggregation between mesoscopic particles, a small change in temperature, pH, or chemical compositions can trigger aggregation and induce remarkable changes in structure and function of colloidal and polymer systems. An aggregated state is not normally an equilibrium state but a kinetically trapped state also called a jammed state. Various kinetic factors in food processing, such as the rate of changes in temperature, water content, and chemical compositions, must be taken into account to establish a complete state diagram of colloid- and polymer-based food systems.
Collapse
Affiliation(s)
- Shinya Ikeda
- Department of Food Science and Technology, The University of Tennessee, Knoxville, Tennessee 37996, USA
| | | |
Collapse
|
33
|
Nicolai T, Britten M, Schmitt C. β-Lactoglobulin and WPI aggregates: Formation, structure and applications. Food Hydrocoll 2011. [DOI: 10.1016/j.foodhyd.2011.02.006] [Citation(s) in RCA: 414] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
34
|
Balakrishnan G, Durand D, Nicolai T. Particle Diffusion in Globular Protein Gels in Relation to the Gel Structure. Biomacromolecules 2010; 12:450-6. [DOI: 10.1021/bm101238r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Dominique Durand
- Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, 72085 Le Mans cedex 9, France
| | - Taco Nicolai
- Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, 72085 Le Mans cedex 9, France
| |
Collapse
|
35
|
Yan C, Pochan DJ. Rheological properties of peptide-based hydrogels for biomedical and other applications. Chem Soc Rev 2010; 39:3528-40. [PMID: 20422104 PMCID: PMC3104857 DOI: 10.1039/b919449p] [Citation(s) in RCA: 530] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Peptide-based hydrogels are an important class of biomaterials finding use in food industry and potential use in tissue engineering, drug delivery and microfluidics. A primary experimental method to explore the physical properties of these hydrogels is rheology. A fundamental understanding of peptide hydrogel mechanical properties and underlying molecular mechanisms is crucial for determining whether these biomaterials are potentially suitable for biotechnological uses. In this critical review, we cover the literature containing rheological characterization of the physical properties of peptide and polypeptide-based hydrogels including hydrogel bulk mechanical properties, gelation mechanisms, and the behavior of hydrogels during and after flow (219 references).
Collapse
Affiliation(s)
- Congqi Yan
- Department of Materials Science and Engineering, Delaware Institute of Biotechnology, University of Delaware, Newark, DE 19716, USA
| | - Darrin J. Pochan
- Department of Materials Science and Engineering, Delaware Institute of Biotechnology, University of Delaware, Newark, DE 19716, USA
| |
Collapse
|
36
|
Vardhanabhuti B, Khayankan W, Foegeding EA. Formation of Elastic Whey Protein Gels at Low pH by Acid Equilibration. J Food Sci 2010; 75:E305-13. [DOI: 10.1111/j.1750-3841.2010.01647.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
37
|
Ako K, Nicolai T, Durand D. Salt-Induced Gelation of Globular Protein Aggregates: Structure and Kinetics. Biomacromolecules 2010; 11:864-71. [DOI: 10.1021/bm9011437] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Komla Ako
- Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, 72085 Le Mans cedex 9, France
| | - Taco Nicolai
- Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, 72085 Le Mans cedex 9, France
| | - Dominique Durand
- Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, 72085 Le Mans cedex 9, France
| |
Collapse
|
38
|
Jones OG, McClements DJ. Biopolymer Nanoparticles from Heat-Treated Electrostatic Protein-Polysaccharide Complexes: Factors Affecting Particle Characteristics. J Food Sci 2010; 75:N36-43. [DOI: 10.1111/j.1750-3841.2009.01512.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
39
|
Sedlák M, Koňák Č, Dybal J. Heat-Set Poly(ethylacrylic acid) Nanoparticles: Combined Light Scattering, Calorimetric, and FTIR Study. Macromolecules 2009. [DOI: 10.1021/ma901504h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marián Sedlák
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovakia
| | - Čestmír Koňák
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic
| | - Jiří Dybal
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic
| |
Collapse
|
40
|
Schmitt C, Bovay C, Vuilliomenet AM, Rouvet M, Bovetto L, Barbar R, Sanchez C. Multiscale characterization of individualized beta-lactoglobulin microgels formed upon heat treatment under narrow pH range conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:7899-7909. [PMID: 19594178 DOI: 10.1021/la900501n] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Aqueous dispersions of demineralized beta-lactoglobulin (beta-lg) were held at 85 degrees C for 15 min at a constant protein concentration of 1 wt % in the pH range of 3.0-7.0. This led to denatured protein content ranging from 20% (pH 3.0) to 90% (pH 5.0). The protein aggregates formed were characterized as to their stability to sedimentation (turbidity), morphology, size, surface charge, ANS surface hydrophobicity, and content in accessible thiol groups. Additionally, the changes in secondary structures of the protein upon heating were followed by Fourier transform infrared spectroscopy (FTIR). Stable dispersions (no sedimentation for 10 min) of individualized beta-lg microgels were obtained at specific pH 4.6 and 5.8, corresponding to an aggregation yield of about 80%. The width of the pH region leading to these microgels was 0.3 pH unit below or above the two specific pH values. Microgels were characterized by a spherical shape and remarkably low polydispersity in size (<0.2). Their z-average hydrodynamic diameter determined by dynamic light scattering (DLS) was between 160 and 220 nm, and their zeta-potential was +30 or -40 mV, depending on the initial pH before heating. Microgels obtained at pH 4.6 displayed a lower binding capacity for ANS and a lower content of accessible thiol groups as compared to those obtained at pH 5.8. Both types of microgels might therefore differ in their internal and interfacial structures. Between pH 4.6 and 5.8, large sedimenting protein particulates were obtained, whereas soluble aggregates were formed at pH <4.6 or >5.8. Interestingly, DLS experiments showed that before heating, beta-lg was mainly present in an oligomeric state at pH 4.6 and 5.8. This result was confirmed by FTIR measurements indicating the stronger contribution of the 1616-1624 cm(-1) spectral band corresponding to intermolecular beta-sheets in the pH range of 4.0-6.0. Upon heating, FTIR spectroscopy revealed that individualized microgels were obtained under pH conditions where a balance between attractive forces arising from protein unfolding leading to the formation of intermolecular beta-sheets (1616-1624 cm(-1 )band) and the repulsive electrostatic forces due to the initial protein net charge was achieved.
Collapse
Affiliation(s)
- Christophe Schmitt
- Department of Food Science and Technology, Nestle Research Center, Lausanne 26, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
41
|
Krebs MR, Devlin GL, Donald AM. Amyloid fibril-like structure underlies the aggregate structure across the pH range for beta-lactoglobulin. Biophys J 2009; 96:5013-9. [PMID: 19527661 PMCID: PMC2712037 DOI: 10.1016/j.bpj.2009.03.028] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 02/05/2009] [Accepted: 03/17/2009] [Indexed: 11/22/2022] Open
Abstract
The protein beta-lactoglobulin aggregates into two apparently distinct forms under different conditions: amyloid fibrils at pH values away from the isoelectric point, and spherical aggregates near it. To understand this apparent dichotomy in behavior, we studied the internal structure of the spherical aggregates by employing a range of biophysical approaches. Fourier transform infrared studies show the aggregates have a high beta-sheet content that is distinct from the native beta-lactoglobulin structure. The structures also bind the amyloidophilic dye thioflavin-T, and wide-angle x-ray diffraction showed reflections corresponding to spacings typically observed for amyloid fibrils composed of beta-lactoglobulin. Combined with small-angle x-ray scattering data indicating the presence of one-dimensional linear aggregates at the molecular level, these findings indicate strongly that the aggregates contain amyloid-like substructure. Incubation of beta-lactoglobulin at pH values increasingly removed from the isoelectric point resulted in the increasing appearance of fibrillar species, rather than spherical species shown by electron microscopy. Taken together, these results suggest that amyloid-like beta-sheet structures underlie protein aggregation over a much broader range of conditions than previously believed. Furthermore, the results suggest that there is a continuum of beta-sheet structure of varying regularity underlying the aggregate morphology, from very regular amyloid fibrils at high charge to short stretches of amyloid-like fibrils that associate together randomly to form spherical particles at low net charge.
Collapse
Affiliation(s)
| | | | - Athene M. Donald
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
42
|
Ako K, Durand D, Nicolai T, Becu L. Quantitative analysis of confocal laser scanning microscopy images of heat-set globular protein gels. Food Hydrocoll 2009. [DOI: 10.1016/j.foodhyd.2008.09.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
43
|
Mercadé-Prieto R, Gunasekaran S. Alkali cold gelation of whey proteins. Part II: Protein concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:5793-5801. [PMID: 19435293 DOI: 10.1021/la804094n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The effect of the whey protein isolate (WPI) concentration on the sol-gel-sol transition in alkali cold gelation was investigated at pH 11.6-13 using oscillatory rheometry. The elastic modulus increases quickly with time to reach a local maximum (G'max), followed by a degelation step where the modulus decreases to a minimum value (G'min). Depending on the pH, a second gelation step will occur. At the end of the first gelation step around G'max, the system fulfilled the Winter-Chambon criterion of gelation. The analysis of the maximum moduli with the protein concentration shows that (i) there is a percolation concentration above which an elastic response is observed (approximately 6.8 wt %); (ii) there are two concentration regimes for G''max and G''max above this concentration, where we have considered power-law and percolation equations; (iii) there is a crossover concentration between the two regimes (at approximately 8 wt %) for both G'max and G''max when both moduli are equal, and this value is constant under all conditions tested (G'max=G''max approximately 4 Pa). Therefore, alkali cold gelation is better represented using two concentrations regimes than one, as observed for other biopolymers.
Collapse
Affiliation(s)
- Ruben Mercadé-Prieto
- Biological Systems Engineering, University of WisconsinMadison, 460 Henry Mall, Madison, Wisconsin 53706, USA.
| | | |
Collapse
|
44
|
Donato L, Schmitt C, Bovetto L, Rouvet M. Mechanism of formation of stable heat-induced β-lactoglobulin microgels. Int Dairy J 2009. [DOI: 10.1016/j.idairyj.2008.11.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|