Re: Autoclaving gum and gelatin

From: Sandy King ^lt;sanking@clemson.edu>
Date: 02/05/05-07:35:08 PM Z
Message-id: <a06020423be2b24ca4771@[192.168.2.2]>

Well, to be perfectly fair the only reason I
"corrected" you was because you were simply way
wrong about the temperature. The plain fact of
the matter is that gelatin can be heated to a
much higher temperature than 140 F and still
retain its setting properties. In mixing gelatin
solutions for making carbon tissue some of us are
heating the gelatin to close to 200 F, for a
short period of time, without experiencing any
problems with setting properties

Granted, there must be some temperature so hot
that it will break down the gelatin within a
short period of time, but 140 F is not even a
ballpark figure for that happening.

Sandy

>On Wed, 2 Feb 2005, Sandy King wrote:
>
>>Well, deja vu all over again. I thought we had
>>put this puppy to rest with previous
>>discussions. My experience is that raising the
>>temperature of a gelatin solution to 140† F
>>for a relatively short period of time (say two
>>hours or less) does not break it down.
>>However, if one were to keep the temperature of
>>the gelatin at 140† F or higher for a long
>>period of time (four hours or more) , or go
>>through several cycles of heating and cooling
>>the solution, it will break down.
>
>I suppose I should have known that mentioning a
>particular temperature would get me "corrected."
>But if you recall I was replying to a question
>about AUTOCLAVING, which the gentleman said
>involved heating the gelatin via overpressurized
>steam to bring solutions or objects to or even
>above 120 centigrade... That's well beyond
>boiling -- and for a duration of time.
>
>(Talk about resting your puppies !)
>
>Judy
>
>>>
>>>Gelatin raised above about 140 F is useless
>>>for sizing purposes if that's what you have in
>>>mind -- it breaks down. Whether it would serve
>>>some other purpose (glue, skin treatment,
>>>whatever) has not AFAIK been described.
>>>
>>>Judy
Received on Sat Feb 5 19:35:23 2005

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