https://digital.csic.es/bitstream/10261/63157/4/Gomez-Guillen-collagenreview_CSIC.pdf

Functional and bioactive properties of collagen and gelatin from alternative sources: A review

Fish gelatin: properties, challenges, and prospects as an alternative to mammalian gelatins

Coacervation of proteins and anionic polysaccharides is both of practical and theoretical interest. From a large body of literature, it seems that the phase separation is mainly entropically driven, and may most probably be attributed to the delocalisation of the counter ions of the protein and the polysaccharide. The protein and polysaccharide appear to form complexes in solution, which can be viewed as new colloidal entities. These complex particles are neutral and exhibit an attractive interaction, which leads to a phase separation of the gas-liquid type in which a (very) dilute colloidal phase coexists with a very concentrated colloidal phase. In the case of strong poly-acids, usually, a precipitate is formed rather than a liquid coacervate phase. The structure of the concentrated polymer phase seems to resemble a continuous polymer phase in which the protein can diffuse around, as well as the individual polysaccharide molecules. Time scales of diffusion vary from milliseconds to days depending on the strength of the interaction. From a rheological point of view, the concentrated phase is much more viscous than elastic and the rheology resembles the behaviour of a (viscous) concentrated particle dispersion. Theoretical developments are limited probably due to the difficulty to describe the (correlated) charge distribution in the system. There is a strong interest in coacervates for the use of encapsulation. For the same reason, much attention is given to replacing the traditional gelatin by milk and plant proteins.

Complex coacervation of proteins and anionic polysaccharides

Structural and physical properties of gelatin extracted from different marine species: a comparative study.

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).

Rheological properties of peptide-based hydrogels for biomedical and other applications.

Rheological characterisation of gelatins from mammalian and marine sources

Thermally reversible acid-induced gelation of low-methoxy pectin

In this article we describe the characterization of a number of gelatin samples extracted from both mammalian (bovine and porcine) and fish (cod) collagens using oscillatory shear. The regime for gel formation and characterization is discussed, and subsequent gel melting behavior is considered in light of both Eldridge–Ferry and Takahashi models for the concentration dependence of the melting temperature. Frequency sweep data for some of the latter samples suggest that, although the junctions are more complex than simple entanglements, they have some features in common with entanglement networks compared to true gel networks (those with an equilibrium modulus). This has consequences on the longer-term behavior of the gels, and suggests, for example, the possibility of gel healing.

P.M. Gilsenan

Papers

Rheological characterisation of gelatins from mammalian and marine sources

Thermally reversible acid-induced gelation of low-methoxy pectin

Viscoelasticity of thermoreversible gelatin gels from mammalian and piscine collagens

Associative and segregative interactions between gelatin and low-methoxy pectin: Part 1. Associative interactions in the absence of Ca2+

Shear creep of gelatin gels from mammalian and piscine collagens