Publication no. C-1998-1008-02R |  VIEW ARTICLE

Rheological Changes in Wheat Sourdough During Controlled and Spontaneous Fermentation.

K. Wehrle (1) and E. K. Arendt (1,2). (1) National Food Biotechnology Centre and Department of Food Technology, respectively, University College, Cork, Ireland. (2) Corresponding author. Phone: +353-21-902064. Fax: +353-21-276318. E-mail: <e.arendt@ucc.ie> Cereal Chem. 75(6):882-886. Accepted July 23, 1998. Copyright 1998 American Association of Cereal Chemists, Inc.

The changing rheological characteristics of wheat doughs during fermentation at 30°C for 72 hr were measured using a controlled stress rheometer. Dynamic oscillation tests were performed at frequencies ranging from 0.01 to 10 Hz. Wheat sourdoughs (dough yield 200) were prepared with a mixed starter culture containing typical hetero- and homofermentative sourdough lactic acid bacteria. Results from the controlled fermentation process were compared to results from spontaneous fermentation. Maximum phase angle values, especially at low frequencies, were closely related to total gas production in the doughs. Complex viscosity decreased during fermentation and reached lower final values for doughs without starter culture. Heating characteristics of doughs after various fermentation times were measured at temperatures ranging from 30 to 80°C. The highest values for complex viscosity were found at approximately 65°C. When heated, fermented doughs produced weaker gels than fresh doughs. The temperatures at which these maxima occurred increased significantly with fermentation time for spontaneously fermented dough.