[alt-photo] Re: The Gum Arabic Report (was: Re: Re: evaporation of gum mixture)

[Katharine Thayer]

I didn't provide links for sources, but if anyone is interested in  
reading further on this, a source I highly recommend is the World  
Bank's report, prepared 2007-2008,  titled "Export Marketing of  
Sudanese Gum Arabic"  which describes how the current insufficient  
supply of A. senegal was manufactured.  It's a 45-page report  
available for download as a pdf.  (I don't have the link but I'm sure  
you can find it by googling; that's how I found it).

It's actually rather heartbreaking to read about how a thriving gum  
trade in which Sudan produced 80% of the world's gum arabic was  
essentially destroyed by what the World Bank calls "inadequate  
marketing arrangements."   Over the forty years that the GAC  
(government-sanctioned monopoly export company) controlled the gum  
export market in Sudan,  Sudan's global market share dwindled from  
80% to less than 50%;  "production and consequently exports  fell  
steadily"  from in the neighborhood of 45,000 metric tons per year to  
15,000 MT or less;  "Low prices received by farmers pushed them to  
favor crop cultivation over acacia trees; the reduced tree cover has  
left  large areas prone to wind and water erosion."  And of the trees  
that are left, according to the recent market reports I cited  
earlier,  a significant proportion are being left untapped because  
the prices to farmers are so low there's no incentive to harvest the  
gum.  In other words, a decision (no doubt unintentional, because  
they wouldn't have really intended to dry up the supply) to set floor  
prices below the level of sustainability for farmers has essentially  
killed the goose that laid the golden egg.  Since other countries  
that have stepped in to take up the slack of the declining gum  
exports from Sudan are producing mostly talha, it's hard to see how  
the insufficient supply of A. senegal will be made up. The World  
Bank's report offers optimism that changing policies will bring the  
supply back, but I guess we'll have to see.

kt



On Jul 5, 2010, at 11:10 AM, Katharine Thayer wrote:

> Suffering from a strained back and having no plans for the holiday  
> beyond reading David McCullough's biography of John Adams and  
> listening to Aaron Copeland's American-themed music, I spent some  
> time yesterday trying to find out more about the structure and  
> properties of Acacia seyal.  I learned very little about that, but  
> found myself drawn into a fascinating study of the political  
> maneuvering around the labeling and marketing of gum arabic.  Since  
> I was researching on the internet, I didn't get a full picture of  
> course, only intriguing bits and pieces.
>
> Some of the things I found out that might be interesting for gum  
> printers to know:
>
> A. seyal until fairly recently has been a very small part of the  
> gum market, like 5% or so.  Now, it represents fully half of the  
> gum arabic market.
>
>  Prior to 1998,  the label "gum arabic" was reserved for gum from  
> Acacia senegal "and closely related species."   In 1990,  a  
> sentence was added to the definition that specified that the the  
> solution must fall within a specific optical rotation range,  that  
> effectively excluded A. seyal.  (A. senegal is levorotary; A. seyal  
> and some other A. species are dextrorotary).
>
> In a series of political maneuvers in 1998-1999 at meetings of the  
> JECFA (Joint Expert Committee on Food Additives) and the Codex  
> Alimentarious Advisory Commission,  the rotation specification was  
> dropped and the definition was expanded to  specifically include A.  
> seyal, with additional language specifying that the two are not  
> technologically equivalent  and can be distinguished by  
> immunoassay.  This expansion of the definition of gum arabic was  
> opposed by Sudan (which has historically controlled the market in  
> A. senegal) but supported by other gum-producing nations like Chad  
> and Nigeria, which produce more A. seyal than A. senegal.  But in  
> the final approval the qualifying language was stripped off and the  
> final approved definition of gum arabic, still in  place, reads  
> simply:
>
>     "Gum arabic is a dried exudate obtained from the stems and  
> branches of  Acacia senegal or Acacia seyal
> (fam. Leguminosae)."
>
> While it is politically advantageous for talha-producing countries  
> to have achieved the inclusion of Acacia seyal in the definition of  
> gum arabic (thereby effectively allowing its use for foods)  it is  
> generally agreed in the trade that gum talha is an inferior  
> product.  As one report put it, "Talha is substantially cheaper  
> than hashab (A. senegal) because it has inferior technical  
> properties for some of gum arabic's uses, such as in the soft  
> drinks industry..."  and exporting countries typically assign A.  
> seyal a lower grade than A. senegal.
>
> I was not able to find much information about the properties of  
> talha, except that in raw form it is more friable (crumbles easily  
> in the hand) and doesn't tend to form hard tears as A. senegal  
> does, that it is dextrorotary, that it contains more tannins, that  
> it exists in two forms: reddish and white.  How it performs in gum  
> printing there is of course no available data on, other than Tom's  
> anecdotal report, and I'll look forward to a further report.  Talha  
> has become the gum of choice for health-food and alternative  
> medicine uses, probably because it's historically been cheaper than  
> A. senegal.
>
> I did come to the conclusion that I was wrong about Kremer's gum.   
> I had assumed that because they described their gum arabic as  
> coming from A. senegal or A. seyal, that they meant that if you  
> bought gum arabic from them, it might be either A. senegal or A.  
> seyal.  Now it seems clear to me that their description is simply  
> copied from the official definition of gum arabic:  "Gum arabic is  
> the dried exudate from A. senegal or A. seyal."  However, they  
> provide sufficiently specific specifications to establish that  
> their gum arabic is indeed A. senegal, based on the optical  
> rotation.   IMO, they should either drop their use of the official  
> definition of gum arabic, or if they are going to keep it, they  
> should at least make it clear in the product description that while  
> officially, gum arabic can either be A. senegal or A. seyal, the  
> gum arabic they sell is A. senegal.
>
> As to Daniel Smith, I have no idea.  All I know is that this gum  
> behaves differently than other gums I've used. It prints the same;  
> it prints beautifully, in fact,  but physically, it behaves  
> differently, it seems like a different gum than  the others I've  
> used.  So it seemed logical to wonder if it's actually a different  
> species of Acacia, but as I said, it's just a suspicion which I  
> have not been able to confirm or disconfirm.
>
> I always thought the size of the crop depended on weather  
> conditions and disruption in areas of conflict and stuff like that,  
> but it turns out that while those factors do play a part,  the  
> thing that has affected the available supply more than anything has  
> been policies set by the Sudan government-run monopoly gum  
> exporting company (which has since been racked with corruption  
> charges and effectively shut down as a government monopoly)   that  
> have resulted in the farmers being paid so little for the gum that  
> it wasn't worth their while to harvest it, and many farmers have  
> cut the trees down to make room  for other crops.  An industry  
> market report from March 2010 warns "A very poor gum acacia crop  
> this year, raising huge concerns about gum prices once the old  
> stocks are depleted. Furthermore, low gum prices in Sudan mean that  
> farmers have no incentives to tap trees and have pursued  
> alternative sources of income. As a result, a large proportion of  
> gum acacia trees remain untapped, drastically reducing the size of  
> the crop."  A Sudan government announcement the same month  
> proclaimed that Sudan's output of gum arabic had reached 49,000  
> tons for the season, which would be a good total for a good year,  
> but this seems fanciful election rhetoric, given that the industry  
> market report for June continues dire:  "The price increase trend  
> of A. senegal continues as the quantities of incoming raw gums keep  
> dwindling.  We foresee that this will remain the case.  The supply  
> of Hand Picked Select (the highest grade of A. senegal) is  
> extremely limited, will not meet demand, and will remain very high  
> priced."
>
> The price of A. senegal in contrast was very low from 1998-2003 or  
> so; let's hope that our suppliers loaded up during those years of  
> cheap gum and won't have to buy while the price is high.
>
> I just think this is all very fascinating, and share it for  
> whatever it's worth to anyone else.  There's a lot more, but that's  
> probably really enough for now, and as I said, this is just bits  
> and pieces I've pulled off the internet, hardly a full account, but  
> I really do think someone should write that book.
> Katharine
>
>
>
> On Jul 4, 2010, at 9:07 AM, Tomas Sobota wrote:
>
>
>> Some months ago I posted here about an experiment I made with gum  
>> talha
>> (Acacia seyal). I received a small quantity from friends in the  
>> Sahrawi
>> camps in southern Algeria, where the tree also grows.
>>
>> I prepared and used this gum just like senegal, with totally  
>> disappointing
>> results: all the gum coat seemed to harden and hence, no image.
>>
>> This test was just a fast experiment, so I cannot swear that some  
>> other
>> variable didn't get in the way. Now that you remind me, I will try  
>> again in
>> more controlled circumstances.
>>
>> Gum senegal in stones (you call them "tears" but what is sold here  
>> is so
>> large that it could only be called crocodile tears) is very easy  
>> to get
>> here, and reasonably inexpensive, that's one of the reasons that I  
>> buy it
>> instead of prepared gum. Also, the work is not that much: the gum  
>> dissolves
>> easily during a night or less.
>>
>> Tom Sobota
>> Madrid, Spain
>>
>> On Sun, Jul 4, 2010 at 5:25 PM, Katharine Thayer  
>> <kthayer at pacifier.com>wrote:
>>
>>
>>
>>>
>>> On Jul 3, 2010, at 1:22 AM, Tomas Sobota wrote:
>>>
>>>  I have never used prepared gum solution. I prepare gum in the  
>>> original
>>>
>>>
>>>> artisanal way, dissolving gum arabic stones in water. Then, I  
>>>> keep the
>>>> solution in dark glass bottles, well stopped and preserved with  
>>>> a few
>>>> thymol
>>>> crystals. Kept in this way, I have never observed any  
>>>> evaporation, not
>>>> even
>>>> in a time span of years. So, what is being described is strange,  
>>>> and
>>>> probably related to the way that the commercial gum is prepared or
>>>> preserved.
>>>>
>>>>
>>>>
>>>
>>> Well, it may be more than that.  I've expressed my suspicion  
>>> before that
>>> the Daniel Smith premium gum may be partly or wholly a different  
>>> acacia
>>> variety (acacia seyal)) since it behaves differently from other  
>>> gums I've
>>> used, not only in this tendency to dry out  but in other ways that
>>> correspond to the description of acacia seyal.  I tried to verify or
>>> disconfirm this suspicion with Daniel Smith but couldn't get an  
>>> answer from
>>> them.   But Kremer, for example, does (or did, last time I  
>>> looked) specify
>>> that some of their gum arabics are  a mixture of acacia senegal  
>>> and acacia
>>> seyal, or even acacia senegal OR acacia seyal.  Like Daniel  
>>> Smith,  other
>>> suppliers (Bostick & Sullivan, Photographer's Formulary) don't  
>>> specify the
>>> acacia variety used in their "gum arabic" (apparently there's no  
>>> requirement
>>> that "gum arabic" be acacia senegal.
>>>
>>> I agree, mixing your own from tears is probably the best way to  
>>> get the
>>> right kind of gum; the reason I don't  has been laziness I  
>>> suppose, not
>>> wanting to bother with the effort of searching out a supply of  
>>> good quality
>>> tears of the right variety in the right grade (maybe this is more  
>>> easily
>>> done on your side of the ocean?) combined with the ease of use of
>>> commercially prepared gum.  I did buy some powder from Daniel  
>>> Smith and mix
>>> it, but if their prepared gum isn't entirely acacia senegal, the  
>>> powder
>>> probably isn't either.  I haven't had an opportunity to use that  
>>> gum yet,
>>> since I've been in the hospital three times in the last year for
>>> heart-related surgeries and explorations and have been deeply  
>>> involved in
>>> another project in the meantime.
>>>
>>> Curious, I started searching online for gum acacia senegal in  
>>> tear or lump
>>> form, just to see how difficult it would be to take this  
>>> approach, and found
>>> that it's not that simple. I went down three pages of google hits  
>>> and found
>>> basically wholesale distributors with minimum orders of from 100  
>>> kg to 6000
>>> kg, and in places like China.  In this group I found several  
>>> distributors
>>> who list their A. senegal as grade 1 and A. seyal (aka "gum  
>>> talha") as grade
>>> 2 or 3, FWIW.    I also  learned that the US imports largely  
>>> processed gum
>>> and European countries impor largely lump gum, processing the gum  
>>> and
>>> reselling it to the US in processed form.   Which might explain  
>>> why it's
>>> easier to find lumps of gum in Europe than it is in the US.
>>> Katharine
>>>
>>>
>>>
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