U of S | Mailing List Archive | alt-photo-process-l | Re: conservation of albumen

Re: conservation of albumen



I would remark (see my previous stanford.edu citation) that a week only at room temperature may not be enough for the complete destruction of albumen glucose:
"Fresh egg white was beaten in a household blender for 1-1 / 2 minutes on high speed, allowed to settle back to liquid form, then incubated in loosely covered containers at 30C. Fermentation of egg white in this manner was described in an article by Stuart and Goresline and in several places in the 19th-century literature on albumen paper manufacturing. Unless speeded up by inoculation with appropriate bacteria, the process takes about 10 days".
"The pH of the albumen falls during the process from approximately 9.0 to 6.0-6.5 [at] completion".
"After 6 days the pH was 8.5"... "After 10 days, the albumen tested negative for glucose and the pH was 6.42".
Alberto


I always thought that yellowing is the function of sensitizing /
incomplete fixing and non ideal storage conditions... You say that non
sensitized paper also will yellow with time?
See http://albumen.stanford.edu/library/c20/reilly1982a.html
The non-smelling brands of albumen paper were those which developed yellowing in the highlights (also in the shadows, but the effect was overwhelmed by the silver layer) more than smelling (albumen aged before coating) papers.
The Maillard reaction has recently been revised also in cooking. It is the responsible of the brown and tasty crust of the bread, of the outer part of a grilled steak, and so on. It is fast at high temperature, but with times long enough it works also at room temperature.
Alberto