Author Topic: veg oil gums  (Read 3789 times)

Offline nathanrobo

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veg oil gums
« on: March 30, 2013, 05:20:08 PM »
Just trying to get a clear understanding of the gums that occur in cooking oil, which are sometimes removed during refining (not always).  If some of these pass into the waste oil that we process, does it make any difference and does it convert in bio, separate with the glyc or is it removed through the different processes for washing fuel. 

With regards to the chemical nature of these gums I found this article: 

http://lipidlibrary.aocs.org/processing/degum-intro/index.htm  Which says, in part:

"The chemical nature of these gums has been difficult to determine. They contain nitrogen and sugar and can start fermenting so they were at one stage thought to consist of glycolipids and proteins. Now we know that these gums consist mainly of phosphatides but also contain entrained oil and meal particles. They are formed when the oil absorbs water that causes some of the phosphatides to become hydrated and thereby oil-insoluble. Accordingly, hydrating the gums and removing the hydrated gums from the oil before storing the oil can prevent the formation of a gum deposit. This treatment is called water degumming."

Is the sticky glaze that can be found on tanks evidence of gumming?
« Last Edit: March 30, 2013, 06:08:03 PM by nathanrobo »

Offline nathanrobo

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Re: veg oil gums
« Reply #1 on: March 30, 2013, 06:16:24 PM »
slightly off topic, but found this with regards to storage of oil

To delay the development of rancid oil, a blanket of an inert gas, usually nitrogen, is applied to the vapor space in the storage container immediately after production. This is referred to as tank blanketing. Vitamin E oil is a natural antioxidant that can also be added to cooking oils to prevent rancidification. (http://en.wikipedia.org/wiki/Cooking_oil).  Wandered if this was replicable in a small inexpensive way. Collecting for some months and reacting 2 or three times a year, means that your oil could well start to smell a bit before you use it - not sure if it makes any difference, but who wants nasty oil in their shed?


Offline Oilybloke

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Re: veg oil gums
« Reply #2 on: March 30, 2013, 07:07:01 PM »
I was hoping that this thread was some remarkable discovery whereby some sort of wine gum/fruit pastille could be made from glyc.....

Offline nathanrobo

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Re: veg oil gums
« Reply #3 on: March 30, 2013, 07:15:19 PM »
I was hoping that this thread was some remarkable discovery whereby some sort of wine gum/fruit pastille could be made from glyc.....

Mate, lol! not sure that kids would go for veg gums though :-))

Maybe I should come up with a recipe, you could be my taster.

« Last Edit: March 30, 2013, 10:09:57 PM by nathanrobo »

Offline Jamesrl

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Re: veg oil gums
« Reply #4 on: March 30, 2013, 09:38:21 PM »
I wa told that Cold pressing = NO gum, Hot press = Gum.

Offline nathanrobo

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Re: veg oil gums
« Reply #5 on: March 30, 2013, 10:09:24 PM »
I wa told that Cold pressing = NO gum, Hot press = Gum.

So how common is cold pressing vs. hot pressing in cooking oil.  How likely is it that we have gum in WVO?  It this the same compound responsible for ring gumming etc. occurring with WVO users?

Offline Chug

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Re: veg oil gums
« Reply #6 on: March 31, 2013, 08:07:58 PM »

As per Jim above and I believe most is hot pressed as they get slightly more oil out, probably coz some of it is gum.


Offline nathanrobo

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Re: veg oil gums
« Reply #7 on: March 31, 2013, 09:15:59 PM »

As per Jim above and I believe most is hot pressed as they get slightly more oil out, probably coz some of it is gum.

So if hot pressing is common and gum is commonly present does it have any detrimental influence in any part of the process either before, during or post reaction?

Offline Jamesrl

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Re: veg oil gums
« Reply #8 on: March 31, 2013, 10:37:44 PM »

As per Jim above and I believe most is hot pressed as they get slightly more oil out, probably coz some of it is gum.

So if hot pressing is common and gum is commonly present does it have any detrimental influence in any part of the process either before, during or post reaction?

Hot press and solvent washed Oils are de-gummed before sale.

Offline K.H

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Re: veg oil gums
« Reply #9 on: March 31, 2013, 11:18:56 PM »
One of the guys on VOD presses his own i think? isnt he a farmer?
RGT springs to mind or maybe it was him the guy replied to
I think cold pressed is now promoted as the top grade along the lines of virgin in Olive oil (Jim you may have to google the word virgin)
« Last Edit: March 31, 2013, 11:21:08 PM by K.H »

Offline Jamesrl

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Re: veg oil gums
« Reply #10 on: March 31, 2013, 11:37:50 PM »
It was RGT and he cold pressed.

You're right about the virgin olives There ain't none round 'ere but then I ain't neva 'eard of any women called Olive eeva.