proteins with a variety of structures can be formed by heating aqueous solutions of
food proteins. The design of specific supramolecular structures may enable several
new functions in food science. For instance, supramolecular structures could encapsulate and protect bioactive ingredients during processing and/or passage through the
gut and, at the same time, allow desired mouth feeling. Concerning the latter
property, controlling the shape and size of constitutive particles is important for
several reasons, one of which is the desired viscosity. The viscosity of solutions
containing linear assembly of proteins increases with the length and rigidity of the
fibrils. If a viscous aspect is required, linear protein assembly can result in the desired
texture even at low protein concentrations. In contrast, if an absence of viscosity is
required, even for high protein content, the design of spherical particles is required.
The size of the spherical particles has to be controlled because a coarse mouth feeling
texture appears for particles of several tenths of micrometres. For instance, in the case
of whey proteins, diversely sized structures ranging from rigid rods to homogeneous
spheres and branched flexible strands can be created (for more details, see the review
by Nicolai et al. [145]). This is because whey proteins undergo denaturation
(via processing) and the denatured forms re-assemble to covalently linked larger
structures like fibrils, spheres or aggregates, which in turn can be assembled to form
gel networks (e.g. yogurt).
During the last few years, there has been an increasing interest in designing new
and efficient food vehicles for encapsulation and protection of sensitive substances
and for their targeted oral delivery. This involves a good control of the formation of
such vehicles, their stability and the conditions of their disassembly. Spontaneous
assembly of food proteins into microspheres, micelles or nanotubes are good
candidates for such applications. Similarly, taking advantage of their availability,
low cost and natural and safe origin, food proteins have been proposed as drug
nanocarriers for oral delivery [133, 146]. However, prior to these applications,
some challenges still need to be met including: (a) understanding the physicochemical forces governing the kinetics and dynamics of the self-assembly processes.
We need to investigate not only protein–protein interactions and self-assembly but
also various molecular interactions between protein molecules and the solute to be
protected; (b) the stability of formed objects toward processing (concentration,
lyophilisation, presence of other components inside food matrix) and storage;
and (c) physicochemical (physiological) conditions of their disassembly, which is
essential for the drug-releasing step. Although the challenge is great, the knowledge
accumulated on the self-assembly and structure of chemical polyelectrolytes and
polyelectrolytes–biomolecules in the field of medical, pharmaceutical and electronics
etc. could help to move rapidly towards these new applications.
Acknowledgements Many thanks to our collaborators: M. Nigen, D. Salvatore, P. Hamon and
M.N. Madec. Part of the work performed in our laboratory was supported by INRA and by the
French National Research Agency (Agence Nationale de la Recherche, grant ANR-07-PNRA-010,
project LACLYS).
94
S. Bouhallab and T. Croguennec
food proteins. The design of specific supramolecular structures may enable several
new functions in food science. For instance, supramolecular structures could encapsulate and protect bioactive ingredients during processing and/or passage through the
gut and, at the same time, allow desired mouth feeling. Concerning the latter
property, controlling the shape and size of constitutive particles is important for
several reasons, one of which is the desired viscosity. The viscosity of solutions
containing linear assembly of proteins increases with the length and rigidity of the
fibrils. If a viscous aspect is required, linear protein assembly can result in the desired
texture even at low protein concentrations. In contrast, if an absence of viscosity is
required, even for high protein content, the design of spherical particles is required.
The size of the spherical particles has to be controlled because a coarse mouth feeling
texture appears for particles of several tenths of micrometres. For instance, in the case
of whey proteins, diversely sized structures ranging from rigid rods to homogeneous
spheres and branched flexible strands can be created (for more details, see the review
by Nicolai et al. [145]). This is because whey proteins undergo denaturation
(via processing) and the denatured forms re-assemble to covalently linked larger
structures like fibrils, spheres or aggregates, which in turn can be assembled to form
gel networks (e.g. yogurt).
During the last few years, there has been an increasing interest in designing new
and efficient food vehicles for encapsulation and protection of sensitive substances
and for their targeted oral delivery. This involves a good control of the formation of
such vehicles, their stability and the conditions of their disassembly. Spontaneous
assembly of food proteins into microspheres, micelles or nanotubes are good
candidates for such applications. Similarly, taking advantage of their availability,
low cost and natural and safe origin, food proteins have been proposed as drug
nanocarriers for oral delivery [133, 146]. However, prior to these applications,
some challenges still need to be met including: (a) understanding the physicochemical forces governing the kinetics and dynamics of the self-assembly processes.
We need to investigate not only protein–protein interactions and self-assembly but
also various molecular interactions between protein molecules and the solute to be
protected; (b) the stability of formed objects toward processing (concentration,
lyophilisation, presence of other components inside food matrix) and storage;
and (c) physicochemical (physiological) conditions of their disassembly, which is
essential for the drug-releasing step. Although the challenge is great, the knowledge
accumulated on the self-assembly and structure of chemical polyelectrolytes and
polyelectrolytes–biomolecules in the field of medical, pharmaceutical and electronics
etc. could help to move rapidly towards these new applications.
Acknowledgements Many thanks to our collaborators: M. Nigen, D. Salvatore, P. Hamon and
M.N. Madec. Part of the work performed in our laboratory was supported by INRA and by the
French National Research Agency (Agence Nationale de la Recherche, grant ANR-07-PNRA-010,
project LACLYS).
94
S. Bouhallab and T. Croguennec