Edible Film Developers

[DarkroomExperimente]

I love the internet.....just ordered some sodium gluconate from eBay so I can compare my homemade concoction to the real thing

 

[DarkroomExperimente]

OK...to take this one step further...it seems hydrolyzing starch into sugars would make a lot more edible things available for use as developers

it seems that hydrolyzing starch generally uses stronger acids than I want to mess with...boiling potatoes in sulfuric acid isn't on my list of things I want to do

gonna try citric acid and/or vinegar and see if I get decent results

anybody out there know of a simple way to convert starch into simple sugars?

 

[MattKing]

anybody out there know of a simple way to convert starch into simple sugars?

I cannot resist...
Doesn't eating them do the job

 

[Alan Johnson]

The first part of demo 2 converts starch to sugar:
http://www.ift.org/~/media/Knowledge Center/Learn Food Science/Mini Experiments/EnzymeChemFlavor.pdf

 

[DarkroomExperimente]

thanks...trying vinegar & starch now

kinda doubt it'll work well...but so easy to try...why not?

 

[removed account4]

anybody out there know of a simple way to convert starch into simple sugars

when i practice zymurgy, i have grains and put them in a sock and leave them in 160-165ºF water for about 30-40mins
i'm not sure, but was told it converts some of the starches to sugars, maybe i am wrong, but it might work with your situation too

 

[DarkroomExperimente]

thanks.....apparently the enzymes to do this are readily available

the starch from today's experiment seems to be turning into a glob...not surprising since I saw instructions for making starch-based plastic that used vinegar/starch/glycerin
...interesting, but not what I was shooting for

 

[DarkroomExperimente]

SUCCESS!!!!!

Tri-x & HP5 in honey developer for 30 minutes look GREAT...basically same recipe as last time but a wee bit more KBr and sodium sulfite

 

[DarkroomExperimente]

just hung up the film to dry...only took a quick peek, but the Tri-X looks better than the HP5....less fog at least

 

[DarkroomExperimente]

there's trouble in Paradise....

first test with pineapple juice dev looked great

tried it again, but with sodium sulfite & KBr...and images were very faint

a mystery to solve here

 

[removed account4]

maybe it was the dye from the maraschino cherry

 

[DarkroomExperimente]

I think I forgot to "shake well before using"

I expected it to be weaker than the honey...so was a surprise when the first test looked the same as honey...need more practice with it

 

[RauschenOderKorn]

Why only one step (developer) instead of going the whole way?

Edible Film and Edilbe paper, please!!!!!!!!

 

[DarkroomExperimente]

sodium gluconate did NOTHING.....hmmmmmm

I was assuming I was generating gluconic acid from glucose & sodium carbonate & that gluconic acid & sodium carbonate were making sodium gluconate

couldn't find where to buy gluconic acid...so I got sodium gluconate

clearly something I'm doing is working...but it ain't what I thought it was

 

[Rudeofus]

Is there any reason why Sodium Gluconate should have any form of developer activity? Looking at its structure it doesn't follow Kendal/Pelz rule ...

 

[pdeeh]

For anyone not familiar with the KP rule, here's a discussion: (there was a url link here which no longer exists)
(not really suitable for the chemically illiterate, like me, but someone else might find it useful )

Back to honey : I was under the impression that sugar was a very strong restrainer, and as honey is mostly a strong sugar solution, can someone explain what's going on that allows it to develop silver halides?
(or what else is in sugar that makes it a developer? Or is it a bit like caffenol, and it's all a bit mysterious?) ?

 

[Rudeofus]

Honey is not just sugar. If this page can be trusted, there is Ascorbic Acid in honey, and some of the flavonoids referenced in this text also look like developers. Especially Quercetin was tested and reported by Alan Johnson (there was a url link here which no longer exists) on APUG.

 

[pdeeh]

thanks.
I meant to say "what else is in honey that makes it a developer?" of course, but you've answered my carelessly phrased question anyway !

 

[DarkroomExperimente]

yes...Honey has more in it than just sugar...etc etc which is why honey worked much better than just the pure sugars alone

However, I tested pure dextrose ( from a pharmacy ), fructose , table sugar/sucrose ( sucrose was first treated with vinegar ) with this same method...and all developed film AFTER they were heated with sodium carbonate...but did nothing if not heated together with sodium carbonate

so..perhaps heating the sugar with sodium carbonate forms something other than just gluconic acid?....

so...next I want to try heating the gluconate with sodium carbonate

 

[DarkroomExperimente]

...and maybe I should stop assuming gluconic acid is involved at all...and just refer to "whatever-I-get-when-I-mix-sugar-with-sodiumcarbonate-and-heat-it"

aka Wigwimswscahi

 

[DarkroomExperimente]

sooo....just verified that honey + sodium carbonate without being heated does nothing

sodium gluconate heated with sodium carbonate does...nothing

sooo...looks like the idea that heating sugar with sodium carbonate generates a gluconic acid developer is pretty much busted

...but heating sugars with sodium carbonate is definitely making SOMETHING that develops film....

and perhaps I'm back to glucic acid https://en.wikipedia.org/wiki/Glucic_acid ...which I think was my original assumption...somehow I got sidetracked onto gluconic acid...probably from reading about the patents on developers that use " 2-keto gluconic acid and derivatives thereof" https://www.google.com/patents/US5147767

 

[DarkroomExperimente]

ok...looking at the K-P rule thread... (there was a url link here which no longer exists)

wondering if glucic acid fits into group (a) ....although it doesn't have a ring structure....soooo

glucic acid: https://en.wikipedia.org/wiki/Glucic_acid

 

[Rudeofus]

If you look at the Kendall-Pelz rule, there is no such requirement for a ring structure. Ring structures just happen to be the most stable form of compound with double bonds and -OH/-NH2 groups. This compound Glucic Acid you came up with looks like it would conform to Kendall/Pelz structure, at least the left tautomere (called the enolic form). Since the wiki article claims that this compound can be made by action of alkalis on Glucose, I think you just discovered why heating sugars with Sodium Carbonate creates a photographic developer.

 

[Alan Johnson]

http://www.omicsonline.org/analysis...-from-northeast-nigeria-2161-1009.1000139.pdf
Here is an analysis of certain honey samples. Looking at table 5 and assuming 100g honey is dissolved in 1L water gives the working solution part A:
Total polyphenols...........~0.065g/L
Vitamin C......................~0.02g/L
Compare with the phenol (catechol) in Hypercat 1:300
Catechol........................~0.033g/L
Vitamin C......................~0.0033g/L
IMO it is quite likely that heating Honey with sodium carbonate solution may cause polyphenols to dissolve.
IDK what particular polyphenols are found in honey.
But, as Rudeofus just noted, an alternative explanation may involve the formation of reducing sugars.

 

[DarkroomExperimente]

thanks...

one other puzzle...when I tested pineapple juice ( sugar content a bit less than the honey developer, but close ) it worked great... but the second time I tried it..a few days later after it was opened & refrigerated...it was very weak...wondering why that is...gonna have to get that figured out since I promised a friend I would develop her Hawaiian photos with a pineapple developer...perhaps I always need to use fresh juice...but would be nice to understand why