Amount of protein in flour

Profile picture for user RichieRich

In most of my bread baking, I use King Arthur unbleached AP flour (11.7%) or KA unbleached bread flour (12.7%). 

 

Does 1% make that much difference.

 

 

…there is about 10% more protein in the bread flour. 

Does it make a difference? I find the crumb of a bread made with bread flour is a bit chewier. A fluffy loaf like a French style baguette, made with low protein flour, is almost like cotton candy. That’s roughly the spectrum, and you can use either. 

-Brad

12.7 / 11.7 = 1.085, so it’s more accurately 8.5% more. I was rounding up. 

 

Just clarifying. 

1% increase but 8.5% more protein. 

However, not all protein is gluten. That's not given. Only sure way to see the difference is to bake two identical loaves side-by-side. 

Profile picture for user alcophile

In reply to by mwilson

I don't know how they measure it. It says "X% gluten-forming protein" on the bag. Maybe it's just a marketing ploy, but I can usually tell the difference between the two flours.

Is there an industry standard for determining gluten-forming protein of flours? I see that the Cereals & Grains Assoc. lists a couple methods for gluten determination:

38-10.01 Gluten—Hand Washing Method
38-12.02 Wet Gluten, Dry Gluten, Water-Binding Capacity, and Gluten Index

I don't know if KAB uses either of these (if any) for their gluten values.

Do you know if any flour mills actually test for gluten content as per the AACC test method? Or, is total protein (Kjeldahl nitrogen) all that is actually tested and reported?

In the USA, I suspect the FDA requires the total protein on the label.

I'm sure they do in some capacity, even if that means sending a sample to a lab to perform the analysis. I imagine testing for wet or dry gluten would be an internal spec. It is not however a legal requirement unlike protein included on nutritional labelling.

"Protein content may be calculated on the basis of the factor 6.25 times the nitrogen content of the food as determined by the appropriate method of analysis as given in the “Official Methods of Analysis of the AOAC International,” except when official AOAC procedures described in this paragraph (c)(7) require a specific factor other than 6.25, that specific factor shall be used."

eCFR :: 21 CFR Part 101 -- Food Labeling

AOAC Official Method 920.87
Protein (Total) in Flour

Terms which could be used to describe those different perspectives of protein percentages are; absolute and relative.

Furthermore, not all gluten is the same.

KA AP is a blend of soft and hard wheat
KA BF is all hard wheat

Profile picture for user RichieRich

What a great response to my question. You all certainly answered my questions and more.