Feasibility Of Milling Gluten Flour - Presentation Transcript
Feasibility of Milling Gluten-Free Flours Jane DeMarchi North American Millers’ Association August 19, 2005
North American Millers’ Association
96% of the US milling capacity for the wheat, corn and oat milling industry
More than 160 million pounds daily
48 corporate members
Supply products to bakers, cereal makers, packaged food companies, brewers, and directly to retail
Cross Contact Begins at the Farm
Producers often rotate wheat, barley, rye and oats on same land - volunteer plants in subsequent years
Several crops may be grown in close proximity on one farm
Great variability from year to year due to
weather, etc.
Farms use the same harvesting, transport, and storage equipment without significant clean out
Some corn and oats are purchased on a contract basis for greater control but mixture is not eliminated in these cases
Grain Storage & Transportation
Trucks and rail cars used to transport grain are another source of cross contact
Grain elevators do not thoroughly clean out silos or equipment when switching grains - in part to minimize dust for health and safety
Elevators have basic equipment to clean grain but not specifically to separate mixed grain
Grain Specifications Allow Other Grains
Grain specifications are based on the US Grain Standards
Oats
Typically contain 0.5-1.0% cereal grain admix
Maximum of 2-3% allowed depending on the grade
Corn
2-4% broken corn and “foreign” material depending on the grade
Milling quality specifications may be more restrictive
The Milling Process
Grain “cleaned” prior to milling
Width grading - sieves
Length grading - rotating drums
Density separation - gravity tables
Grains that are very different in size and shape (such as wheat and corn) are easier to separate than like-sized grains
Deficiencies of Cleaning Technology
Length, width and weight of kernels of different grain can be similar in many circumstances
Barley Oats Rye Wheat
New Technology
Color or optical sorting machines
Expensive
Low capacity
Not reliable - if color differences are small
Internal Cleaning Procedures
Good Manufacturing Practices
Mill equipment is regularly cleaned and inspected. It is critically important to a mill that product dust not be allowed to gather.
Internal cleaning is dry cleaning, vacuum and wipe out
Special procedures are used for changing grains.
HACCP includes analysis of allergen risk.
Testing
Corn and wheat mills generally do not conduct tests for cross contamination on finished product.
ELISA tests are not used for cross contact of grains in mills. Granulation and small test samples cause results to vary dramatically
In an oat mill, representative samples are hand sorted and visually inspected
Economics of Grain Milling
Many mills are dedicated to a single grain or have dedicated lines
Mills operate as close to 24/7 as possible
Shut down time is minimized
Cross contact grains can not be cleaned out 100%. Mills can not lose too much of the desired grain in the separation process
Testing every bag of product is not feasible
Emphasis on prevention
Concentrations of Gluten Bearing Cereal Admix
Research has not been done to quantify the levels of cereal admix in oats or corn on an industry wide basis.
Individual customers may establish standards but so far it is not common
Variability from year to year is large
Trace Grains In Finished Products
Varies depending on product and portion size. Concentrations of wheat protein in oat flour will be higher than those in oat flakes due to the milling process.
Example: 28 gram serving of instant oatmeal
7.5 milligrams of wheat and barley protein - approximately 40% (3 milligrams) of which would be gluten.
(Assumes a .03% contamination of wheat at 15% protein and barley contamination of .16% at 14% protein content)
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