Foaming Properties of White Wheat Flour-Yoghurt Mixture as Affected by Fermentation

Effect of fermentation on the foam stability (FS) and overrun (O) of a white wheat flour-yoghurt mixture was investigated using response surface methodology with concentration (0·5–1·5%, w/v) and whipping time (30–120 s) being the independent variables. Regression equations for predicting the FS and O were developed. Results suggest that concentration had the most pronounced effect on the overrun while concentration and whipping time were both effective on foam stability. Response surface plots suggest that fermentation causes a decrease in the overrun, possibly resulting from the change in the structure of protein due to breaking down of molecules into small nitrogenous molecules as a result of fermentation. Fermented sample has a better foam stability (i.e8·0±0·1 min) than unfermented control sample (i.e5·0±0·1 min) at the same concentration and whipping time.