1996 Volume 59 Issue 3 Pages 418-427
The pH dependence of physical retardance (PRD) of thermally irradiated gelatins was studied. And the effects of the degeneration of thermally coagulated substance, free amino acids and active impurities on PRD were investigated.
PRD increased with the decrease of molecular weight which was resulted from thermal irradiation. However, when calcium ions and free amino acids coexist, PRD decreased at pH 4 ripening.
It was assumed that these changes were due to the charge shift of gelatin molecules. However we found also that the change of PRD by thermal irradiation was caused not only by the charge shift but also by other factors to be identified.
