Effect of pH and water irradiation with the electromagnetic field on the gelation of gelatin solutions

Abstract

The rate of gelation was determined from the curve slope of the dependence of the gelatin solution relative viscosity on time at different pH. It was found that slow gelation of 2 % gelatin solution occurs at T = 293 K, and the degree of fluidity significantly depends on рН. The most stable jellies are formed at the isoelectric point (рН = 4.7). There are significant differences in the physical state of jellies prepared on irradiated water and control samples. Prepared on unirradiated water jellies are more mobile and retain fluidity at T = 293 K regardless of рН. There is a partial or full melting of the jellies with the increase in temperature at 297 K; however solid state remains for irradiated systems at pH = 4 and 4.7. It was shown that the viscosity of the irradiated solution and the rate of its increase are higher in comparison with the control samples at all pH values except рН = 2. The observed phenomenon can be caused by the weakening of the hydration of polymer macromolecules in the activated water, which facilitates their association and the formation of a structured system.