2005 Volume 15 Issue 4 Pages 247-252
When fish or meat with collagen is boiled down and cooled, the obtained juice contains a significant amount of gelatine, hardens and forms a gel called “Nikogori”, whose deliciousness is due to its unique texture.
A series of measurements was conducted to clarify the effects of the components and the cooking condition on the physical properties of “Nikogori” . We examined the lightness, pH, rupture characteristics, 1H-NMR and 170-NMR data.
As a result, the mechanical properties of the “Nikogori gel” were found to be dependent on the material, the boiling time and the presence of seasonings such as wine vinegar, soy sauce or rice vinegars. We postulated that the difference in the heating times and pH of the solution had an influence on the solubilization of the collagen. The fish (flatfish) formed a gel after a short heating time, and gel strength decreased after a 20minute heating time. The pork shanks formed a gel firmer than the fish one, and the strength of its gel was a maximum after 90 to 120 minutes of heating. The end of the chicken wing particularly produced a stable and strong gel during a long heating. On the other hand, the cow shanks without any bone and hide did not form a gel even after 240minutes.It was suggested on the basis of the NMR result that factors other than the collagen influenced in the physical properties of “Nikogori” .
