. The Biochemical journal. Biochemistry. 2:u) R. STirui It is ^iMuMiilly hclicvcd lluit a-^flutin, tlio iu'tunl ji^elatinising constituent ol jfolatin, is ;ra(lually hydiolysed, by heating, to ^-jilutin which has no ten- dency to gehitiniso oven at low toniperaturcs, and as a matter of fact, the longer the sol is heated, the further the hydrolysis goes. Adopting this point of view, therefore, we may say that the higher the concentration of a-glutin, the larger the initial gelation velocity; that when its concentration is higher than a certain critical value, the gelation velocity increases wit
. The Biochemical journal. Biochemistry. 2:u) R. STirui It is ^iMuMiilly hclicvcd lluit a-^flutin, tlio iu'tunl ji^elatinising constituent ol jfolatin, is ;ra(lually hydiolysed, by heating, to ^-jilutin which has no ten- dency to gehitiniso oven at low toniperaturcs, and as a matter of fact, the longer the sol is heated, the further the hydrolysis goes. Adopting this point of view, therefore, we may say that the higher the concentration of a-glutin, the larger the initial gelation velocity; that when its concentration is higher than a certain critical value, the gelation velocity increases with the time until the viscosity grows beyond bounds; and that when the concentration is lower than this critical value, the gelation velocity decreases with the time, until the viscosity ultimately reaches a finite, limiting value. It is not clear whether concentration of jS-glutin affects th'ese facts or not. l)_>7. 8 12 16 20 24 28 32 36 40 44 4i Fig. 2. Gelation of 3 per cent, gelatin sol. (previously heated at 70° ). These conclusions are supported by similar experiments with a 1 per cent, gelatin sol represented in Fig. 3. Curves 1, 2, 3 and 4 are viscosity-time curves for portions previously heated at 80° for O'l, 1'2, 4 and 11 hours respectively. We see that the gelation velocity decreases with the time even when the sol has been heated for only a short period. That is to say, the gelation belongs to the second, and never to the first case. Obviously the concentration of a-glutin in this case has been lower than the critical concentration from the beginning. The numerical value of the critical concentration of a-glutin cannot be found, since we do not know the concentration of a-glutin in solid Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Biochemical Society (Great Britain); Univ
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