|Simsek, Senay -|
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 11, 2012
Publication Date: September 1, 2012
Repository URL: http://handle.nal.usda.gov/10113/58358
Citation: Doehlert, D.C., Simsek, S. 2012. Variation in beta-glucan fine structure, extractability, and flour slurry viscosity in oats due to genotype and environment. Cereal Chemistry. 89:242-246. Interpretive Summary: The soluble fiber in oats, called beta-glucan, can reduce serum cholesterol and the risk of heart disease in people who eat enough oats. We have studied how the environment affects the concentration, solubility and structure of this fiber to help determine which environments are best for producing the most healthful oat. Although we can identify environments that produce poorer quality oats from a health benefit prospective, we cannot identify what it is about those environments that caused the decreased quality. We have found that dry environments cause subtle changes in beta-glucan structure, but do not know if this would have any affect on the health benefits.
Technical Abstract: Effects of genotype and environment on oats on beta-glucan extractability,flour slurry viscosity, and beta-glucan polymer fine structure were tested. Certain environments had unpredictable catastrophic effects on slurry viscosity. Learning the cause of such viscosity loss should be of high priority for health interests. Environment also had strong effects on beta-glucan extractability, whereas genotype had no significant effect. Fine structure of beta-glucan was evaluated from the frequencies of oligosaccharides from lichenase hydrolysis of the beta-glucan polymer. Significant differences in fragment frequencies were found associated with both genotype and growth environment. The high beta-glucan cultivar, HiFi, had lower DP3 fragment frequency and higher frequencies of larger fragments than other cultivars with moderate beta-glucan concentration. Drier environments tended to yield lower DP3 fragment frequencies as well. Enzymological studies have indicated that cellular environments with higher UDP-glucose supply to serve as substrate for the beta-glucan synthesis resulted in higher frequencies of DP3 fragments. Drier environment and genotypes with more beta-glucan synthetic potential provided cellular environments with lower UDP-glucose. In a separate experiment, we found that extractable beta-glucan had higher frequencies of DP3 fragments and lower frequency of DP4 fragments. The observed variations deserve consideration for potential influence on functional properties.