The Fresh Loaf

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Protein content VS. Gluten Content: An Experiment

Mebake's picture
Mebake

Protein content VS. Gluten Content: An Experiment

I Have been been wondering about the correlation between Protein content in flour and their useability for baking. Through some web search,I learned that Protein content of a flour gives nothing more than a hint as to the strength of the flour. I read that some amino acids (that make up protein) are usually soluble and contribute little to the strength of a flour.

In search of more information, I came across this video : http://www.youtube.com/watch?v=i6oQNo4gpeE. and instantly, i thought of applying the procedure to my flours. 

I have several flours, but have purchased lately some Hovis strong white bread flour, with protein of 12g. On the other, i usually stock some regular plain /all purpose flour. Though nothing is printed of the protein content on polypropylene sack of 10Kg. of the latter flour, except: a star (as in white flour, 2 as in wholewheat), and a statement : "Bakes good everytime!", I always assumed that the my plain flour comes from the regular flour sold in 1Kg, and 2 Kgs. paper bags. I could be wrong?? there is nothing such as "Bread flour" in Dubai. It is either: "All purpose flour", "Chapati Flour" or "Whole Meal Flour".

So, i ventured on to the comparision. I Made two identical dough of  each flour, and let them rest in the fridge for 1/2 hour, and then drain their starch by washing them under running water. I obtained two blobs of Gluten.

The two blobs of Gluten. The one on the right is the Hovis, and the left is the All Purpose.(note the Smooth texture of the Hovis one, though could be attributed to the long rest period - 5 hours) in the fridge, as i had to leave the house.

 

After they dried, i weighed both glutens. All Purpose is: 12 grams (12%), and Bread Flour is: 10.7 grams (10.7%)! Quite the opposite of what i was expecting..!!!

Is this a reliable way of knowing the actual protein content of a flour? i can understand

That a 12% protein flour has some dissolved amino acids that were washed away, to become 10.7% protein gluten, but a 10.5% protein flour becomes a 12% dry gluten?? Furthermore, the All Purpose had more wet gluten than the Strong Bread flour.

Although, those results are hardly conclusive, i find myself quite intrigued by them.

Anyone?

 

 

 

 

lumos's picture
lumos

Very interesting experiment, Khalid! Thank you very much for sharing.

I've been always feeling I'm just stubbing in the dark about gluten level of flour because all the manufacturers in UK only state protein content on the package (In Japan where I originally come from, many artisan bread flours, especially French flours, which you can get at least 20 different brands, many of them imported from France,  do state gluten level AND ash level) . But they have a formidable population of home bakers who bake artisan-style (mainly French) breads regularly who demand those information, so that sort of luxury may never happen in this country, sadly. (they have much higher proportion of stay-at-home mums who are the main driving force of the artisan baking boom over there.)

I join you and expectantly wait for someone will come and answer to your question, too. :)

nicodvb's picture
nicodvb

Hi Khalid, the seitan test you did is a decent way to know the amount of gluten obtainable with a given flour, but you could have gone a bit beyond and tested the quality of the glutens: stretching the glutens obtained you could have compared the relative strengths. A stronger gluten stretches more than a weaker one before breaking, but even the simple unwashed doughs behave the same way.

Moreover you have to keep into account that the drying process may have not completed perfectly. I found out that the microwave is a marvelous instrument to dry perfectly a dough, in very few minutes. Anyway, even so having the raw amount of proteins doesn't say a lot in my opinion.

I'm toying right now with a flour bought from a local mill. It was milled from a variety of wheat called Blasco (anyone knows it?), it's supposed to have 16% of proteins, W400 and P/L roughly 1.5 (quite a typical american high gluten flour if I'm not mistaken, but with an extraordinary amount of proteins). It doesn't absorb a lot of water and it doesn't even seem to make such a strong gluten, but I can guarantee that it can bear VERY long fermentation times: a sweet bread that I made was left to rise for 28 hours! and it came out perfect without overproofing. Quite contraddictory, but these are the facts.

Flours are so misterious and unpredictable things...

Mebake's picture
Mebake

Thank, Lumos. The reason i'am doing experiments, is that i want to get hold of a good flour with a decent strength, and a reasonable price tag. I've managed to find a patent white flour, marketed as: "all purpose patent flour" with a protein content of 12.5%, and relatively cheap. However, when i Put it to the test alongside my regular plain flour, the resultant gluten was less in weight (29g), and it did not bloom much as compared to the plain flour. What is going on here?

Thank you Nico. I did infact do just that. The Bread flour Gluten was smoother, softer, more coherent, and makes a smooth sheath of gluten when stretched. The All Purpose Gluten was a little shaggy (i didn't give the dough the substatial rest i gave to the hovis one), not as smooth, but yet manages to creat a good sheath when stretched, though not as smooth as the Hovis.I did dry them considerably. you are right, Nico, its a tricky world of flours. Its best to stick with baking the leavened doughs and comparing the results then.

 

AndyM's picture
AndyM

Hi Khalid-

Nice Experiment!  Here's a thought about the results (it's somewhat speculative, but hopefully based on some scientific principles).  First the science (at least as I understand it):

Gluten is made up of two separate proteins, glutenin and gliadin.  Not coincidentally, gluten also has two properties, elasticity and extensibility.  Elasticity is contributed by glutenin, and it is the property that makes the dough "spring back" when stretched.  This results in what we think of as "strength".  Balancing the tendency to spring back is the quality of extensibility, which is contributed by gliadin.  This quality allows the dough to stretch effectively.  In order to make gluten, you need both qualities: too much elasticity, and the dough feels rubbery and stiff (this is referred to as a "bucky" dough); too much extensibility and the dough is unworkable and cannot hold its shape effectively.

Now for the speculation: I've always thought of the important piece of gluten information as the balance between the glutenin and the gliadin, rather than any single number expressing "gluten" or "protein" content, and it's seemed to me that flours can vary substantially in this balance while still accurately reporting the same percentage of "protein".  The issue then becomes one of the quality of the gluten (i.e. the balance between glutenin and gliadin) rather than just the quantity of gluten (which is often reported by proxy as the percentage of protein).

So, could your results come from differences in the balance between the crucial gluten proteins?

Andy

ananda's picture
ananda

Hi Khalid,

This is an important concept you are investigating, and thank you for writing it up and with such clear photos and other data.

Andy, you make a really important point about the balance of the glutenin and gliadin fractions found in different flours which go together to make gluten when flour is combined with water and mixed to form dough.

As an illustration, European flour tends to produce more extensible dough, where North American bread wheats produce doughs of greater elasticity.

I believe globulin and albumen are also found within the protein mix, though these are more soluble than the gluten forming fractions.

What I would say, Khalid, is that this is a way you can understand the gluten potential of the flour you are using, not the protein content.   Especially if you have wholegrain flours in the mix, as they contain plenty of proteins in the outer portions of the grain which contribute nothing in terms of gluten.   You have worked out the answer here: protein figures quoted on the bag are a mere guide to the gluten potential in the flour.   As you have shown, a flour with 10.5% protein quoted produces more gluten than a flour with 12% quoted.   Although with more thorough drying, I would expect your AP flour to drop just below 10.5%, and take it as read that the strong flour would also reduce by a similar amount.   As Nico points out, it is very difficult to drive off all the moisture.

I wanted to go a little further on this if you don't mind, as it serves as an excellent illustration of the high quality [in gluten terms] of North American-type AP flour, and a ready appreciation of just how strong their High Gluten flour really is.   Additionally, it shows the UK Strong flour to be inferior [in gluten potential] to AP.

I carry uot these tests regularly with students, and attach a couple of photos here:

The labelling is wrong, in that the "cake flour" is actually Carrs Excel Soft Flour, which would be offered up as Plain Flour equivalent in the supermarket for retail.   I just wanted to demonstrate the difference between a top quality AP flour such as King Arthur [that is just an example, Khalid, I don't know what brand, or the origin of the AP flour you are using] and the very poor gluten quality in the UK soft flour.   I do hope this brings greater understanding and appreciation of why many of us look for only Strong flour for our regular breadbaking, and why I advise against using plain flour.   I do, however, accept that it can be used to mix into strong flour to create an acceptable blend when making the likes of baguettes and ciabatta, where a greater level of extensibility is required.

Many thanks for your interesting post

Best wishes

Andy

Yerffej's picture
Yerffej

A wonderful post and equally great and informative follow up comments.

Jeff

lumos's picture
lumos

Hi, Khalid,

 i want to get hold of a good flour with a decent strength, and a reasonable price tag.

Yeah, I know how you feel. It's really frustrating you can't just go to your local supermarket and pick up a kind of flour you'd want, having to try to improvise with what you can get, isnt' it?  Here in UK, there're only a few of artisan miller who sell Type 55 flour in retail sized package and no one sells Type 65 for retail.  Though their price for one bag is not that much more expensive than the flours from supermarket, if you regard the cost of P & P, you end up paying more than twice as much. (I don't want to bulk buy flour because I have an awful experience in the past when bags of flour I'd bought in bulk got infested with bugs only after a few months and had to throw all away.)

I just made a few loaves of ciabata today using Doves Farm pasta flour (Italian 00) for the first time and it turned out rather nice; soft but chewy crumb with open texture. I bought this flour a few months ago for the first time because my regular Italian 00 flour was  out of stock but the pasta I made from it turned out too soft and I was quite disappointed.  But judging from the result I got in today's ciabata, it looks like it can be a good substitute for French or Italian bread flour. Its protein level is only 9.9%, but it contains Durum flour, so I suspect its gluten level may be quite reasonable. When you add water, it's soft and supple but you can feel a sort of strength you can't feel from UK plain flour.  I think I'll try this flour when I make baguette next time and see what happens.

 

Thank you Andy and Andy for your thought and information.

ananda says;

I do, however, accept that it can be used to mix into strong flour to create an acceptable blend when making the likes of baguettes and ciabatta, where a greater level of extensibility is required.

That's the problem. Most of bread I bake are that sort of bread or French campagne style bread which I want very open texture, so normal bread flour in UK is too strong for my needs. (and probably different type of wheat, too.)  So until some day a miracle happens and half a population of this country suddenly decide they want to bake baguettes by themselves at home every week and demand for that sort of flour shoots up (which is very unlikely) , I'll just have to keep on improvising with what I can get......or surrender and buy 55 flour from Shipton or other artisan millers, paying more for P & P than actual price of flour.....

Meanwhile, I'll experiment with my new discovery, Dove's pasta flour, to see if it can really be a reliable substitute. ;_

ananda's picture
ananda

Hi lumos, and I appreciate your dilemma.

The problem is that English wheat, generally, [not the intensively produced pseudo-Canadian industrial/chemically-reared East Anglian "bread basket" stuff!] is just that bit weak for consistent bread production.   What I have come to find with experimenting with the Gilchesters flours sits very neatly with the comments made on Khalid's last post.   You can make a really nice Miche with the Gilchesters Farmhouse [high extraction] flour if used in combination with a wheat leaven made from regular strong white flour; see here: http://www.thefreshloaf.com/node/23811/miche-using-stiff-levain-and-gilchesters-organic-farmhouse-flour but if you try to use the local flour in the leaven and final dough, life becomes much more difficult; see here: http://www.thefreshloaf.com/node/23415/baking-allbritish-flour

Neither French nor Italian flour could ordinarily be described as "strong", but I believe they would have a higher gluten content than a comparable English flour.   The 10.5% reading would be quite typical of good levels of protein content, whereas a similar English flour would struggle to reach 10%.   So your idea to blend is probably the best option, given that the Strong flour hovers over the 12% mark.   However, using the stronger flour in the pre-ferment is the best option, and then blend some plain in with some strong flour for the final dough.   Not ideal, but I agree that our Strong flour on its own is too strong for baguettes, ciabatta etc.

Incidently, durum flour is noted for being high in protein, but low in gluten-forming proteins.   But with careful mixing, I'm sure a flour at almost 10% would make quite good ciabatta-type breads.

All good wishes

Andy

Mebake's picture
Mebake

Thanks,  Lumos, Andy, and Andy... for your thoughts and replies. I stress here, that i did dry both gluten balls all the way to the end.. i cracked both balls .. they were steaming fromk within.. so i continued baking them while cracked open until i drove almost all of the moisture out. They result balls were then squashed into powder and weighed.

However, i think that when you deal with a flour of pure origin.. as King Arthur's, you are dealing with few variables, and thus you have a consistent and predictable flour strength, and performance. In my case, however, My plain flour which is definitely a blend of different wheats from more than a continent, the resultant flour strength and performance is hardly predictable, as different flours from different harvests around the world behave in a different manner, and when blended together, you'll end up with a flour with unexpected behavior.. and thus cannot be judged solely by its printed protein content.

 

 

ananda's picture
ananda

Hi Khalid,

You are quite right to point out that there will be variables within flour brands as milled and sold.

Even KA will not always have exactly the same specification.

Instead, all millers will use a blend of grain in the grist to produce specific flour types/brands.   These will then be tested to make sure that the performance will be as expected.   This is decided using a number of tests.   The tests will be expected to produce results which fall within a certain range.   Examples are the sort of test you mention here, the Alveograpg tests Nico references, falling number tests to measure amylase activity, plus moisture and colour grade tests.   there are others.

I believe you are right to assume that KA flours will be more consistent as the specification demanded is much tighter, so the variations allowed in these tests is a lot narrower.   Clearly the gluten potential in the AP flour you have tested is well above what you would expect.   If the total protein content is expected to be 10.5% and you have extracted 12% soluble protein in this test, then the true protein level must be a lot higher than 10.5%.   I believe the result for the Hovis flour is much more typical of flour with that specification you have quoted.

Good work mainman!

Best wwishes

Andy

lumos's picture
lumos

Hi, Andy. Thank you for the reply.

The problem is that English wheat, generally, [not the intensively produced pseudo-Canadian industrial/chemically-reared East Anglian "bread basket" stuff!] is just that bit weak for consistent bread production.

Yes, that's why Waitrose blend Canadian wheat to their Leckford Estate wheat to make it stronger (13.6% protein). It really has lovely flavour and creamy colour which is great when I want to make simple toasting/sandwich loaf, but it's really not suitable for French or Italian breads.

I've read your posts on Gilchesters flours and know you're quite happy with their flour, but unfortunately the only stockist of their flour in my area is Waitrose and they only sell Gilchester spelt flours (many varieties) and rye flour. So obtaining their flour would mean I'd have the same problem as trying to get Shipton flours; paying more for P & P than for actual cost of flour, and I know Shipton's Type 55 flour and ciabatta flour work  for those kinds of bread from my past experience with them, it's just the matter of if I should just give in and start buying their flour again. The problem is that several of my frineds and neighbours buy the bread I bake, so doubling the cost of flour because of extra P & P would mean I'd have to reflect it in the price they pay, which I'm not sure they'll be happy about.

Neither French nor Italian flour could ordinarily be described as "strong", but I believe they would have a higher gluten content than a comparable English flour.

Yes, their flour is 'softer' than UK bread flour; their typical protein level is about same or often even lower than UK's plain flour, but they feel much stronger  and absorbs more water when you make dough with it than comparable UK flour with similar protein content, probably because of higher gluten as you said.  Interestingly that's how I felt when I used Dove's pasta flour to make ciabatta; the dough was very soft and silky to touch but yet it has some sort of 'strength' or 'body' in it, just like dough made from Type 55 flour feels, though the crumb texture was different.

Home bakers in Japan often mention on their blog how each flour (Type 55) behaves differently even gluten or protein levels are same, so there must be something more than just 'gluten level' to each flour which makes each flour's unique characteristics; maybe different varieties of wheat, where it's grown, which season it's harvested, how it's milled, etc. etc. I'm just jealous they're in a position they can compare different Type 55 flours so easily!

Also the way they (especially French)  mill their wheat is different from how UK's bread flour is milled, I believe, which makes a diffrence in ash level, too,  so I'm aware that just blending UK bread and UK plain flour would not really emulate French flour.  I always add a tiny bit of WW flour or wheat germ to compensate for the lack of ash level in UK flour. Again, I'm stubbing in the dark here, too.

 

Khalid,

My plain flour which is definitely a blend of different wheats from more than a continent, the resultant flour strength and performance is hardly predictable, as different flours from different harvests around the world behave in a different manner, and when blended together, you'll end up with a flour with unexpected behavior.. and thus cannot be judged solely by its printed protein content.

I'm in the same boat. It's a hard life, isn't it, being a bread geek. :p  Let's persevere, and one day we may see the light....

Best wishes! :)

 

 

 

Mebake's picture
Mebake

I did some web search.. and read some resarch papers, and learned the following:

Gluten Index is the best indicator of a Flour's Gluten Quality. Furthermore, there appears to be no correlation between a flours gluten quantity, and it Quality. In short, and as my fellow TFL mates have pointed out, Gluten Quality (measured by Gluten Index) rather than quantity is the best indicator of a flours baking capabilities.

I refer you to this page: http://www.ftb.com.hr/39/39-353.pdf

A Flour of a Gluten Index : 75 to 90 is considered optimal for baking (large loaf volume), while anthing less than 70 is weak (even if the gluten quantity is more), and more than 90 is too strong for bakeries (results in lower loaf volume).

Now comes the important part. How do you measure Gluten Index? Essentially, it is a test that a blob of gluten undergoes that forces the gluten centrifugally, thus measuring the extensibility of the flour and its resistance to tear, which is the quality you're looking for in a dough.

As i'am uncapable of performing such a test at home, i'll have to believe my senses, and test the quality of the gluten by means of stretching it and testing its resistance and extisibility before it tears.

Oh, i hope that one day, Mills will mention Gluten Index on their flour bags. Until then, my eyes will be my friends.

 

ananda's picture
ananda

Hi Khalid,

Gluten quality has always been the over-riding factor in my understanding too.

And yet, when millers add Vital Dry Gluten when blending for the grist [and they can do this without declaring it as an additive, of course], and when bakers add the same substance to their doughs, where do you think the VAG comes from?

My understanding is that in the UK, VAG is extracted from our own homegrown flours which have low levels of gluten, and not very good quality either.

Can anyone explain that?

Happy Rubber Banding

Andy 

Mini Oven's picture
Mini Oven

Glad you posted your experiment.  I have often used this method when confronted with a flour bag I could not read often in a foreign language.  As if protein content isn't a foreign language by itself!   It does give me some idea of where to change a recipe when the dough and ev. the bread fails.  Fails to act like normal anyway.  There are also flours that test so low in gluten bonding that additional proteins help a great deal.  The more complex, the better.  Off hand I think of milk and egg white.  A light went on in my head with Andy's comment:

I believe globulin and albumen are also found within the protein mix, though these are more soluble than the gluten forming fractions.

And I naturally remember albumen is the same name for egg white which according to wiki, contains 40 some odd proteins.  Eric Hanner has asked me often enough why I pitch an egg white into the my dough on occasion.   All those proteins ought to do something for my missing gluten, connecting and reconnecting protein bonds!  

I found this on a google with globulin in bread: http://ddr.nal.usda.gov/bitstream/10113/12382/1/IND20591401.pdf

An interesting read even when it tends to go over my head.

ananda's picture
ananda

I'll catch up with the article on globulin shortly.

regards albumen, absolutely!   It's the most important enriching functional ingredient in the Chollah dough to me.

A great teaching aid to instil in students that we add enriching ingredients to dough to achieve specific improvements in the dough, just like the industrialists add chemicals, enzymes, emulsifiers etc..

The up side of egg white is that increase in strength.   The down side can result in a drier dough; I'm pretty sure Nico has discussed this on occasions in the past.

We're off for a walk; the sun is shining and it is now hot!   Northumberland countryside here we come!

BW

Andy

Mini Oven's picture
Mini Oven

I brought my tomato plants inside!  If I walk out the door now, I blow into the next village with one step with no chance of making it back within the hour!  I could just end up in Vienna paying only a return train fare!   

Mini

Mebake's picture
Mebake

I was tempted to buy baker's flour in bulk from the same vendor whom i bought the all purpose plain flour from, but i dreaded the additives they use: Ascorbic acid, and bread enzymes. Ascorbic acid is tolerable, but enzymes.. oh please no.

I'am quickly turning from a Home baker into a mad scientist! Help..!

Mini Oven's picture
Mini Oven

as long as you're clear what you're mad about!  I think there is a little mad scientist in all of us.  

Chuck's picture
Chuck

Protein content of a flour gives nothing more than a hint as to the strength of the flour.

In general yes, but there's an important exception: for white flour grown in europe/north-america, almost all the protein is gluten, so "protein content" (which is easier to measure accurately) is a good approximation of "gluten content".

 

... and then drain their starch by washing them under running water

The method of fully developing the gluten, using slowly running cool water to wash away everything but the gluten matrix, then drying and weighing what's left, is indeed the only way I've ever heard to measure gluten content reasonably. But as few people ever actually do it, I suspect the procedure is fraught with potential errors.(I suspect for example the measurement that suggests gluten content is higher than the labelled total protein content is simply a measurement error:-)

The scientific way to find out your tests' validity is to do several separate tests of the same flour, and see how much your answers vary. If you get something like 10.5%, 9.5%, 11%, 10.7%, and 9.9%, work on making your procedure more repeatable before you put too much stock in the results.

 

 ... in Dubai. It is either: "All purpose flour", "Chapati Flour" or "Whole Meal Flour"

In many locales, including yours, flour is highly variable in unintuitive ways, and the labelling is almost useless. If you can accurately rank (not measure absolutely, just "rank":-) the various available flours in your locale, and publish the results, you'll be doing a very positive public service for lots of bakers.

Mebake's picture
Mebake

Thanks for the reassurement, Mini. Its Quite interesting actually, the use of egg whites to strengthen a weak flour, why haven't i thought of that. Thanks for the link you posted, it was very useful in understanding proteins that make up flour.

Thank you Chuck. I have repeated the gluten test on my plain flour several times, with consistent results. True, it may be optimal to rank Flours based on their actual baking performance, rather than their protein content. It is only that Protein Bit that bugs me, as it seems to be misleading with the flours i purchase locally. For instance, i found a flour imported from a neighboring country. the flour bag says: Patent Flour, All purpose: for Bread, Rolls, Biscuits?!, cakes?!, and Indian Flat breads. the protein content printed is : 12.5g per 100g of flour. The price of the flour is reasonable. How could a 12.5 Protein Flour be marketed as all purpose, and be used for biscuits, and cakes/pastries?

 

nicodvb's picture
nicodvb

Khalid, I have a flour with 13.5% proteins that is *very strong* (W 400, I use it for panettone and pandoro because it also bears very well 24 hours of fermentation without tearing) that on the bag is recommended to make ... biscuits! And the company that sells it is undoubtely the most serious in italy, although they are more austrian than italian :-)) but all the flours they sell are so strong... they have to occupy every sector of the market.

Mini Oven's picture
Mini Oven

Yes, when starch is added to it, it can.  One third starch to two thirds AP, sifted together.  Rice, corn or other starch or maybe gluten free flour.  If the flour is too weak for bread (which I doubt) and falls apart while fermenting, try adding an egg white into the liquids.  

ananda's picture
ananda

Hi Khalid,

I have to say your question at the end is not an unreasonble one.   Commercially, in the UK I have used a couple of flour brands which are marketed as "Baker's Grade".   I deem that to be an attempt to produce something the equivalent of "All Purpose".   In other words, an attempt to produce a flour blended so it can make an acceptable scone, pastry, bread, cake and biscuit.   What it means at the commercial end is a means to save money for the baker by being able to buy a cheap and ordinary flour which is the only flour the baker chooses to use and which produces only mediocre quality products.   In College, I sampled one bag of Carrs Baker's Flour, and immediately ditched any attempt to use this type of flour, even for making scones and savoury short paste for sheeting.   The resulting products were so disappointing in terms of flavour/taste, and especially eating quality.   I now use a strong flour for regular breads and laminated doughs, and a soft flour for cakes and biscuits and short pastes.   For scones I mix 40% strong and 60% soft.   This is altogether better for me as it allows me to purchase top quality bread flour and top quality soft flour allowing students to trust in the raw materials available to them and have confidence that they can make high quality products with these materials.

Obviously I cannot speak first hand of American AP type flours and their suitability across the product range.   However, the knowledge I have about many areas of North America having an ideal climate to produce hard wheat with good quality gluten-forming proteins leads me to think the AP flour will not necessarily be that good for scones, pastries, cakes and biscuits, but will be a reliable bread flour.   I will happily be led by more informed posters who use this flour on a regular basis for a multitude of differing types of baking.   My feelings, however, are that Baker's Grade, or, All Purpose are somewhat contradictory terms.   As a baker, I much prefer to have a range of different flours available and suitable to make different bakery products, than to be reliant on just one flour to do the job for anything I decided to make.   Yet, surely that is the very definition of the phrase "All Purpose", if you take it as its literal meaning?

Regarding Chuck's useful reminder that most of the protein in white flour is gluten-forming, perhaps we need to be reminded that the endosperm from which white flour is milled, contains globulin and albumen, in addition to the glutenin and gliadin fractions which combine during the mixing process to give us the gluten matrix?   Albumen is soluble in water, so that is washed out in tests such as the one you carried out.   Globulin is apparently soluble in alchohol, but not in water.   I don't have any data giving further information about the relative content of these proteins, but they are still a component part of the protein make up of white flour, and do not contribute to the gluten matrix.

On the subject of carrying out this gluten washing, I have to say that I regard it as a standard test available to the baker, which allows for instant analysis which can illuminate a problem the baker has encountered, immediately.   I could compare it to dropping a piece of dough into water to see if it floats, to test for yeast presence, or, tasting the dough to check if salt has been added, in terms of its usefulness for immediate fault/problem diagnosis.   Washing out the starch in the dough allows an informed baker to assess the merits of the mixed dough in terms of the insoluble protein content, especially, the glutenin and gliadin fractions which have come together to form the gluten network.   The reason why there is little need to carry out this test [or should be little need] is that bakers buy flour of pre-determined quality, subjected to various tests to verify that the flour will perform as it is supposed to.

This leads nicely to the actual gluten tests which are carried out in the lab.   The washing test described above is not used for this purpose, scientifically.   In the article Mini cited [see:  http://ddr.nal.usda.gov/bitstream/10113/12382/1/IND20591401.pdf] there is good description of the tests for gliadin.   If you refer to Edwards, W. P. (2007) The Science of Bakery Products London: Royal Society of Chemistry, there is good description of the individual testing of the glutenin and gliadin fractions, as well as reference to albumen and globulin.   Out of the science lab, the more common test used by the millers and bakers is the near infra-red analyser [NIR].

But the beauty of this washing test, to me is not how scientific it is.   It is the immediacy of the physical evidence available that helps the informed baker to make an accurate assessment of the quality of the gluten potential in the dough he/she is working with at that moment in time.   It is a test I always introduce as a weapon of assessment for my bakery students to use, from Level 2 upwards, and I encourage them to use it.

As you have identified already, flour properties will vary to some degree all the time, from batch to batch, and in differing environments , and over time too.   So, getting very involved in this sort of detail seems to me to be a bit of a waste of time...and flour.   But carrying out this test every once in a while, especially if your flour is under-performing is well worth while.   Highly accurate determination of gluten potential requires complex chemical procedures.   Washing out the starch gives immediate and tangible evidence that there may be a problem with the dough on acvcount of different levels of gluten to those a baker might expect.

Very best wishes

Andy      

Chuck's picture
Chuck

...the endosperm from which white flour is milled, contains globulin and albumen, in addition to the glutenin and gliadin fractions...

Yep, but the key question seems to be how much? 30%? 5%?  If it's only 5%, then the approximation of ProteinContent~GlutenContent seems to be a reasonable shortcut for bakers to use. Sorry if my wordsmithing appeared to imply anything further; it certainly wasn't intended to. 

My own understanding is indeed anectodal and quite possibly erroneous - it's that because of hundreds of years of "selection" (call it "natural genetic modification" if you wish:), "most" of the protein in the endosperm is in fact glutenin and gliadin. (Of course the growing climate may change the absolute amount of protein quite a bit  ...but whether it's X or Y, as far as I know the same percentage of whatever amount there is is gluten-forming.)

(I'm assuming -perhaps incorrectly- that the home baker flour evaluation problem Khalid faces is much worse than the problem most "westerners" face, partly because the available flours are imported from so many different parts of the world with vastly different standards, partly because expectations and typical uses are so different among different segments of purchasers, and partly because "truth in labelling" is honored even less than we're used to. For example most folks here know the very concept of "All Purpose" flour is a not-all-that-useful contradiction in terms, but Khalid's example has that dubious terminology being pushed to a new extreme.)

Mebake's picture
Mebake

Very misleading.. I wish all millers put down figuers and descriptions that really reflect the actuall use of the flour. Well, my friend, Nico.. We Home bakers will have to keep on juggeling flour packs around every time we bake a certain recipe.. It can be fund though, leaves some space for creativity..! but if you wish to duplicate a recipe you'll have to write everything down.

 

Mini Oven's picture
Mini Oven

but the pro bakers learn all this stuff and more in baking school.   They pay for it.   They also get a spec. sheet from the mills that you and I don't normally see.

There is something to be said about the local home-bakers protecting their secrets of what works in their area using the available ingredients.  Many have used the tried but true results of trial and error.  When pried for their secrets, it comes down to magic or something in the air.   The flour sounds good to me.  

Mebake's picture
Mebake

I was Wondering at the reason behind their labelingm, Mini!. i was not questioning the possibilities of its usage for cakes/pastris..

Mebake's picture
Mebake

True...! Mini.. So True..

Syd's picture
Syd

Very interesting experiment, Khalid.  Just noticed this thread this evening.  How much salt did you add to your experiment?  The video calls for 2g of salt dissolved in 200ml of water,  and then uses 11g of this salted water and 20g of flour in making the dough.  If my calculations are correct, that works out to be 0.55% (salt as a percentage of flour weight i.e. bakers percent).  Is there any reason for such a low amount of salt, given that most bread recipes call for 2%? Would it have anything to do with the strengthening effect salt has on gluten and would a different percentage of salt provide a different result?  I am wondering, for instance, if a higher percentage of salt would bind up more gluten in the flour and thus end up with a weightier blob of gluten?

A lot of interesting points raised in this thread. 

Best,

Syd

 

Mebake's picture
Mebake

Thank you Andy. So, i could have washed away proteins that would other wise have contributed to the gluten count in the bread flour.? Anyway, i'll stick to the gluten quality, if ever iam to do this test again. And as chuck rightly said, Flour Labeling in my part of the world is misleading, largely due to the fact that it has to appeal to so many cultures.. But may not appeal to the hardcore home baker, especially the Artisan one. So, until i can source a reasonably priced (non-organic) quality bread flour, i'll keep on blending.

Thanks Syd. This coud be true to some extent, but i wouldn't think that the total gluten weigh will differ much.. if at all..

 

jatashankar's picture
jatashankar

Hi All,

I ma not much concerned about the quality of dough or flour .i have different doubts which are,

1. I ahve read that protien consists of many components.when we heat the gluten what happens to protein and its components. After heating protein does the protein count varies

2.i had seen globules of dried soya which ar very light and hard when dried.Can i use them to get the high quantity of protein.what is the protein content of dried , light and hard soya globules?

3i had seen neutrela packs which also have same soya protein but those are soft.They claim to have more protien,so should i infer that soft soya globules are higgh in protein as compare to dried, light and hard soya globules ?