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)