|Mcmullen, Michael - PLNT SCI, NDSU, FARGO, ND|
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 7, 2003
Publication Date: October 1, 2003
Citation: DOEHLERT, D.C., MCMULLEN, M.S. CHARACTERISTICS OF SPROUT DAMAGE IN OATS. CEREAL CHEMISTRY. 2003. Vol. 80(5):608-612. Interpretive Summary: Sprout damage occurs in grain when mature grain is left in the field and rainfall induces the seed to start the germination process. Sprout damage of any grain invariably results in decreased market value, but little is known of the effects of sprout damage in oats, or even how to evaluate it. In this study, we identified sprout damaged oats from a field study using the falling number or the stirring number tests, which are routinely used to identify sprout damaged wheat and barley. We also observed that sprout damaged oats break excessively during the dehulling process. We artificially sprouted oats in the laboratory to confirm this observation. We speculate that enzymes produced by the grain during the sprouting process weaken the cell walls of the grain, which make them more susceptible to breakage.
Technical Abstract: Sprout damage of oats can occur when mature grain is left in the field after maturity and rainfall induces the germination process in the seeds. Although characteristics of sprout damage have been described thoroughly in many grains, including wheat, rye, triticale and barley, such characteristics have not been identified in oats. During our field studies, we have observed that some field sites occasionally exhibited much higher rates of groat breakage during dehulling. Determination of falling number values on groats from these locations indicated that a location with higher rates of breakage also had lower falling number values, suggesting that the higher rates of groat breakage were associated with sprout damage. This hypothesis was confirmed with artificially sprouted oats, where sprouted grain exhibited lower falling number and lower stirring number values, indicating increased alpha-amylase activity in the sprouted oats. Sprouted oats exhibited much more breakage during dehulling, and decreased beta-glucan integrity, as evaluated from the viscosity of steamed groat flour slurries. We hypothesize that the increased breakage was a result of the weakening of cell walls, as evidenced by the loss of beta-glucan integrity.