PFG-NMR self-diffusion in casein dispersions: effect of probe size and protein aggregate size

S. Salami, C. Rondeau, J.P.M. van Duynhoven, F. Mariette

Research output: Contribution to journalArticleAcademicpeer-review

14 Citations (Scopus)

Abstract

The self-diffusion coefficients of different molecular weight PEGs (Polyethylene glycol) and casein particles were measured, using a pulsed-gradient nuclear magnetic resonance technique (PFG-NMR), in native phosphocaseinate (NPC) and sodium caseinate (SC) dispersions where caseins are not structured into micelles. The dependence of the PEG self-diffusion coefficient on the PEG size, casein concentration, the size and the mobility of casein obstacle particles are reported. Wide differences in the PEG diffusion coefficients were found according to the casein particle structure. The greatest reduction in diffusion coefficients was found in sodium caseinate suspensions. Moreover, sodium caseinate aggregates were found to diffuse more slowly than casein micelles for casein concentrations >9 g/100 g H2O. Experimental PEG and casein diffusion findings were analyzed using two appropriate diffusion models: the Rouse model and the Speedy model, respectively. According to the Speedy model, caseins behave as hard spheres below the close packing limit (10 g/100 g H2O for SC (Farrer & Lips, 1999) and 15 g/100 g H2O for NPC (Bouchoux et al., 2009)) and as soft particles above this limit. Our results provided a consistent picture of the effects of diffusant mass, the dynamics of the host material and of the importance of the casein structure in determining the diffusion behavior of probes in these systems.
Original languageEnglish
Pages (from-to)248-255
Number of pages8
JournalFood Hydrocolloids
Volume31
Issue number2
DOIs
Publication statusPublished - 2013

Fingerprint

Casein
protein aggregates
Caseins
Dispersions
casein
Nuclear magnetic resonance
Proteins
polyethylene glycol
sodium caseinate
Polyethylene glycols
diffusivity
Sodium
micelles
Micelles
Protein Aggregates
lips
nuclear magnetic resonance spectroscopy
Molecular weight
Lip
molecular weight

Keywords

  • dynamic light-scattering
  • sodium caseinate
  • mechanical-properties
  • electron-microscopy
  • gel microstructure
  • wave spectroscopy
  • micelles
  • suspensions
  • coagulation
  • milk

Cite this

@article{1897125c458247239b1f3ab1469bfabd,
title = "PFG-NMR self-diffusion in casein dispersions: effect of probe size and protein aggregate size",
abstract = "The self-diffusion coefficients of different molecular weight PEGs (Polyethylene glycol) and casein particles were measured, using a pulsed-gradient nuclear magnetic resonance technique (PFG-NMR), in native phosphocaseinate (NPC) and sodium caseinate (SC) dispersions where caseins are not structured into micelles. The dependence of the PEG self-diffusion coefficient on the PEG size, casein concentration, the size and the mobility of casein obstacle particles are reported. Wide differences in the PEG diffusion coefficients were found according to the casein particle structure. The greatest reduction in diffusion coefficients was found in sodium caseinate suspensions. Moreover, sodium caseinate aggregates were found to diffuse more slowly than casein micelles for casein concentrations >9 g/100 g H2O. Experimental PEG and casein diffusion findings were analyzed using two appropriate diffusion models: the Rouse model and the Speedy model, respectively. According to the Speedy model, caseins behave as hard spheres below the close packing limit (10 g/100 g H2O for SC (Farrer & Lips, 1999) and 15 g/100 g H2O for NPC (Bouchoux et al., 2009)) and as soft particles above this limit. Our results provided a consistent picture of the effects of diffusant mass, the dynamics of the host material and of the importance of the casein structure in determining the diffusion behavior of probes in these systems.",
keywords = "dynamic light-scattering, sodium caseinate, mechanical-properties, electron-microscopy, gel microstructure, wave spectroscopy, micelles, suspensions, coagulation, milk",
author = "S. Salami and C. Rondeau and {van Duynhoven}, J.P.M. and F. Mariette",
year = "2013",
doi = "10.1016/j.foodhyd.2012.10.020",
language = "English",
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journal = "Food Hydrocolloids",
issn = "0268-005X",
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}

PFG-NMR self-diffusion in casein dispersions: effect of probe size and protein aggregate size. / Salami, S.; Rondeau, C.; van Duynhoven, J.P.M.; Mariette, F.

In: Food Hydrocolloids, Vol. 31, No. 2, 2013, p. 248-255.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - PFG-NMR self-diffusion in casein dispersions: effect of probe size and protein aggregate size

AU - Salami, S.

AU - Rondeau, C.

AU - van Duynhoven, J.P.M.

AU - Mariette, F.

PY - 2013

Y1 - 2013

N2 - The self-diffusion coefficients of different molecular weight PEGs (Polyethylene glycol) and casein particles were measured, using a pulsed-gradient nuclear magnetic resonance technique (PFG-NMR), in native phosphocaseinate (NPC) and sodium caseinate (SC) dispersions where caseins are not structured into micelles. The dependence of the PEG self-diffusion coefficient on the PEG size, casein concentration, the size and the mobility of casein obstacle particles are reported. Wide differences in the PEG diffusion coefficients were found according to the casein particle structure. The greatest reduction in diffusion coefficients was found in sodium caseinate suspensions. Moreover, sodium caseinate aggregates were found to diffuse more slowly than casein micelles for casein concentrations >9 g/100 g H2O. Experimental PEG and casein diffusion findings were analyzed using two appropriate diffusion models: the Rouse model and the Speedy model, respectively. According to the Speedy model, caseins behave as hard spheres below the close packing limit (10 g/100 g H2O for SC (Farrer & Lips, 1999) and 15 g/100 g H2O for NPC (Bouchoux et al., 2009)) and as soft particles above this limit. Our results provided a consistent picture of the effects of diffusant mass, the dynamics of the host material and of the importance of the casein structure in determining the diffusion behavior of probes in these systems.

AB - The self-diffusion coefficients of different molecular weight PEGs (Polyethylene glycol) and casein particles were measured, using a pulsed-gradient nuclear magnetic resonance technique (PFG-NMR), in native phosphocaseinate (NPC) and sodium caseinate (SC) dispersions where caseins are not structured into micelles. The dependence of the PEG self-diffusion coefficient on the PEG size, casein concentration, the size and the mobility of casein obstacle particles are reported. Wide differences in the PEG diffusion coefficients were found according to the casein particle structure. The greatest reduction in diffusion coefficients was found in sodium caseinate suspensions. Moreover, sodium caseinate aggregates were found to diffuse more slowly than casein micelles for casein concentrations >9 g/100 g H2O. Experimental PEG and casein diffusion findings were analyzed using two appropriate diffusion models: the Rouse model and the Speedy model, respectively. According to the Speedy model, caseins behave as hard spheres below the close packing limit (10 g/100 g H2O for SC (Farrer & Lips, 1999) and 15 g/100 g H2O for NPC (Bouchoux et al., 2009)) and as soft particles above this limit. Our results provided a consistent picture of the effects of diffusant mass, the dynamics of the host material and of the importance of the casein structure in determining the diffusion behavior of probes in these systems.

KW - dynamic light-scattering

KW - sodium caseinate

KW - mechanical-properties

KW - electron-microscopy

KW - gel microstructure

KW - wave spectroscopy

KW - micelles

KW - suspensions

KW - coagulation

KW - milk

U2 - 10.1016/j.foodhyd.2012.10.020

DO - 10.1016/j.foodhyd.2012.10.020

M3 - Article

VL - 31

SP - 248

EP - 255

JO - Food Hydrocolloids

JF - Food Hydrocolloids

SN - 0268-005X

IS - 2

ER -