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

Re: conservation of albumen

Yes, I noticed that -> will wait at least 10 days if I ever get into
albumen in the future.


19 Ocak 2009, Pazartesi, 11:51 am tarihinde, Alberto Novo yazmış:
> 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 30°C. 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