Corn gluten meal is the principal protein of corn (maize) endosperm consisting mainly of zein and glutelin. It is a byproduct of corn processing that has historically been used as an animal feed. Despite the name, corn gluten does not contain true gluten, which is formed by the interaction of gliadin and glutenin proteins.
Corn gluten meal is one product of wet-milling corn as well as starch, germ oil meal, corn gluten feed, and steep liquor. Corn is steeped in water mixed with sulfur dioxide and ground to separate germ from the endosperm to extract oil. The endosperm goes through screenings to separate starch and proteins from the corn fiber or bran. The remaining starch and proteins are centrifuged to separate the starch from the corn gluten meal.
The use of corn gluten meal as an herbicide was patented in 1991, but, like many food-related substances used for gardening, is not regulated in the US. Corn gluten meal breaks down over time and can act as a fertilizer due to a high nitrogen content, but it should not be applied to areas where it is likely to wash directly into watersheds due to nitrogen runoff.
The effectiveness of corn gluten meal as a preemergent is not conclusive. The added nitrogen can allow turfgrass to outcompete weeds, and the meal can act as mulch to prevent weed emergence, but will not affect emerged weeds.
Corn gluten meal is commonly used as livestock feed containing about 65% crude protein. It can be source of protein, energy, and pigments for livestock, and is used in pet foods for digestibility. Corn gluten meal is occasionally confused for corn gluten feed, which instead has approximately 22% crude protein and is a mixture of bran, steep liquor, and maize germ oil from the milling process.
- 21 CFR 184.1321
- Heuze V., Tran G., Sauvant D., Renaudeau D., Lessire M., Lebas F., 2015. Corn gluten meal. Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/715 Last updated on October 29, 2015, 14:09
- "Corn Gluten Meal Research Page". Iowa State University of Science and Technology. Archived from the original on 2008-07-11. Retrieved 2008-05-24. CS1 maint: discouraged parameter (link)
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- Cardozo, Anna. "Weed Management in Lawns Guidelines--UC IPM".