Publication no. C-2004-0912-02R |  VIEW ARTICLE

Pasting and Thermal Properties of Flours from Oat Lines with High and Typical Amounts of beta-Glucan.

Mirela Colleoni-Sirghie (1), Jean-Luc Jannink (2), and Pamela J. White (1,3). (1) Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011. (2) Department of Agronomy, Iowa State University, Ames, IA 50011. (3) Corresponding author. Phone: 515-294-5980. Fax: 515-294-8181. E-mail: <pjwhite@iastate.edu> Cereal Chem. 81(6):686-692. Accepted March 19, 2004. Copyright 2004 American Association of Cereal Chemists, Inc.

Experimental oat lines high in beta-glucan (6–7.8%) and traditional lines (3.9–5.7% beta-glucan) were used to evaluate the effect of beta-glucan on pasting (by rapid viscoanalysis) and thermal properties (by differential scanning calorimetry) of oat flours. Significant correlations established between beta-glucan concentration and the pasting parameters after amylolysis demonstrated the role of beta-glucans in oat pasting. The relative decrease of peak viscosity (PV) observed after enzymatic removal of beta-glucans was correlated with beta-glucan concentration (r = 0.880, P < 0.010) and reconfirmed their contribution to pasting. A significant increase of PV with beta-glucan concentration obtained under conditions of either autolysis (deionized water used for dispersion) (r = 0.89, P < 0.010) or inhibition (silver nitrate solution used for dispersion) (r = 0.91, P < 0.001) might be explained by an increase in water retention capacity caused by the beta-glucans. Predictive models of beta-glucan concentration based on the whole pasting profile or selected profile regions were developed using partial least squares (PLS) regression. Prediction of beta-glucan based on the whole profile obtained in the silver nitrate solution was the most effective (r = 0.93, correlation coefficient of predicted vs. analyzed beta-glucans, P < 0.050). No correlations were observed between the thermal properties of oat flours and the beta-glucan concentration.