Effect of pH change on size and nanomechanical behavior of whey protein microgels

Autor: Christophe Schmitt, Marta Martin, Csilla Gergely, Sylvie Marchesseau, Asma Bahri, Dominique Chevalier-Lucia
Přispěvatelé: Ingénierie des Agro-polymères et Technologies Émergentes (UMR IATE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Department of Chemistry, Nestlé Institute of Material Sciences, Nestlé Research, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA), Nestle Research, Lausanne
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Journal of Colloid and Interface Science
Journal of Colloid and Interface Science, Elsevier, 2019, ⟨10.1016/j.jcis.2019.07.083⟩
Journal of Colloid and Interface Science, Elsevier, 2019, 555, pp.558-568. ⟨10.1016/j.jcis.2019.07.083⟩
ISSN: 0021-9797
1095-7103
Popis: International audience; Microgels specific structural and functional features are attracting high research interest in several appli- cations such as bioactives and drug delivery or functional food ingredients. Whey protein microgels (WPM) are obtained by heat treatment of whey protein isolate (WPI) in order to promote intramolecular cross-linking. In the present work, atomic force microscopy (AFM) was used in contact mode and in liquid to investigate WPM particles topography and mechanical properties at the nanoscale at native pH (6.5) and acid pH (5.5 and 3.0). Prior to AFM, WPM particles were captured on a gold substrate via low energy interactions by means of specific monoclonal antibodies. AFM images clearly showed an increase in the size of WPM particles induced by pH decrease. AFM in force spectroscopy mode was employed to monitor the elasticity of WPMs. The obtained effective Young’s modulus data showed a significant increase in stiffness at pH 5.5 and pH 3.0, over 15-fold compared to native pH. These findings indicate that the mechanical profile of the WPM network varied with the pH decrease. The WPM topographic and nanome- chanical changes induced by acidification were most likely due to substantial changes in the shape and inner structure of WPM particles. Our results suggest that internally cross-linked structures, modified by acidification could display interesting functional properties when used as a food ingredient.
Databáze: OpenAIRE
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