Submitted to: Institute of Food Technology
Publication Type: Abstract Only
Publication Acceptance Date: 12/7/1995
Publication Date: N/A
Technical Abstract: Oats have long been recognized as a healthy food because of their high-quality protein and high level of water soluble dietary fiber (beta-glucan). Unlike other cereal grains, oats are used with rare exception as a whole-grain flour or flakes. The rheological properties of whole-grain oats flour are important for both food and non-food applications of oats. Heat-treatment of oat grain had significant effects on the viscosity of oat flour slurries. Steamed oats produced highly viscous slurries and the viscosity increased with time. Roasted (105 degrees C, 120 min) oats had much lower viscosity and after an initial viscosity increase, the viscosity was degraded rapidly. Combination of heat treatments (steamed/roasted, roasted/steamed) had different effects from either single treatment. Roasted/steamed samples had the highest viscosity among all of the heat treatments. Steamed/roasted samples had lower apparent viscosity than the steamed samples, but they had significantly higher viscosity than roasted samples. Oat flour particle size is another factor that effected the rheological properties of oat flour. Small particle size oat flour (through 0.2 mm) screen generated significantly higher viscosity compared to large particle size oat flour (through 1.0 mm screen). The oat flour slurry viscosity development with time was also affected by temperature. Viscosity built up much faster and higher at 40 degrees C than at 20 degrees C or 30 C. Oat flour slurry viscosity was correlated with 1-3), (1-4)-beta-D-glucan concentration in the oats flours. Treatment of oat flour slurries with lichenase largely eliminated the viscosity.