Handling-System Changes Can Reduce Grain Mixing

By Erin Kendrick-Peabody
October 27, 2003

Want to keep unwanted grains from slipping into your box of organic cornflakes or canister of Basmati rice? With more specialty grains flowing into the marketplace, there is a growing need for grain-handling programs that can effectively segregate grains so that there's no unwanted mixing.

Zeroing in on the commingling that can occur during grain unloading and storage, a scientist with the Agricultural Research Service recently identified the parts of a grain elevator that may contribute to mixing and assessed how flushing with a quick burst of "cleansing" grain can lessen the problem.

Maintaining the genetic and physical purity, or separateness, of grains is the goal of identity preservation (IP) programs in the grain industry. IP systems are needed to segregate specialty grains with unique desired qualities, such as low-linolenic canola and organic varieties.

At the farm level, recent studies have examined the impacts of pollen drift and planting distance on IP for growing crops. But, until now, little was known about the role that processing facilities, especially grain elevators, can play in strengthening IP efforts for harvested grains.

For the study, ARS engineer Mark Casada ran two different colors of corn through equipment at the agency's research grain elevator at the ARS Grain Marketing and Production Research Center in Manhattan, Kan. He wanted to simulate an operation in which one type of grain would be received and binned prior to another, without any special cleaning in between. Casada determined the level of flushing needed to remove most of the residual grain that could otherwise mix with incoming grain.

This new data about effective flushing methods can be used by operators of similarly designed elevators. Elevator owners and operators have had few cost-effective options for practicing IP in their aging facilities.

Also in development is software--a decision-support system--that will make specific recommendations to elevator owners and operators about flushing. It will also spell out equipment modifications needed to reduce grain commingling.

ARS is the U.S. Department of Agriculture's chief scientific research agency.