Gelatin gel properties

The aim of this work is to elucidate the mechanisms of gelation of the gelatin gels and to establish the relations between the microscopic structure and the rheological properties. 

Thus a full investigation of the properties of gelatin gels has to be done on samples issued from the same batch, to allow quantitative comparisons of the results. 

Moritaka, H., Nishinari, K., Horiuchi, H., and Watase, M. (1980). Rheological properties of aqueous agarose-gelatin gels./. Text. Studies 11 257-270. 

The physical properties of gelatin gels and their dependence on protein concentration, temperature, molecular weight, pH, and added reagents have been thoroughly reviewed by Ferry (1948a). We shall refer only briefly to supplementary work. 

Norziah, M., Al-Hassan, A., Khairulnizam, A., Mordi, M., and Norita, M. (2008). Characterization of fish gelatin from surimi processing wastes Thermal analysis and effect of transglutaminase on gel properties. Food Hydrocolloids In press, corrected proof, DOI 10.1016/j.foodhyd.2008.12.004. 

Jongjareonrak, A., Benjakul, S., Visessanguan, W., and Tanaka, M. (2006). Skin gelatin from big eye snapper and brown stripe red snapper Chemical compositions and effect of microbial transglutaminase on gel properties. Food Hydrocolloid. 20,1216-1222. 

The properties of the curdlan gel have been shown to be intermediate between those of the elastic gelatin gel and the brittle agar gel. The relationship between the breaking strength and the elastic modulus of agar, curdlan, and gelatin is shown in Figure 9. 

Figure 9. Gel properties of agar, curd-lan, and gelatin, data of Kimura, et ah...

Conversely one can now also obtain a complex from this again by passing a very dilute gum arabic sol of pH 3 7 over the gelatin spheres. They shrink then once more in their dimensions and again assume the properties of the complex gels and swell reversibly with salts. The mobile complex partner thus can not only leave the gel on suppression of the complex relations but can just as well be taken up in the positive gelatin gel when it is offered from without and the conditions for the contracting of complex relations is favourable (pH 3 7 in the absence of salt). 

Because of a reduced overiap of absorption bands of different chromophores whose absorption maxima are located at slightly different wavelengths, it is desirable to measure LD spectra at low temperatures in order to determine the orientation of the terminal emitter iinker poiypeptide in APC I. Unfortunately, gelatin gels are not suitable for low temperature studies, and we therefore investigated the iinear dichroism properties of APC i in stretched PVA fiims at 100 K (Fig. 4). The maximum in the LD spectrum appears at 653 nm with a prominent shoulder at 677 nm which we attribute to the 95 kD linker polypeptide. 

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