The results showed significant differences in the bread making performance of commercial oat flours. Overall, it was established that in order to achieve high quality oat bread wholegrain oat flours should present low batter viscosity, low flour water hydration capacity, starch content of above 65%, protein content of about 12%, low starch damage and coarse particle size. In addition, it was assessed whether certain oat varieties yield better quality bread than others by investigating their bread making properties under optimised conditions, which allowed the evaluation of oat constituents affecting oat bread quality.

Considerable differences were observed in the bread crumb structure which could be attributed to protein and fat content, starch properties as well as ?±-amylase activity. Hence, selection of oat varieties in relation to their composition is essential in order to obtain superior oat bread quality.

In addition, the effect of sourdough on oat bread quality was investigated. Oat sourdoughs were produced by spontaneous fermentation and subsequent back-slopping until a stable microbiota was obtained. Identification of the lactic acid bacteria showed dominance of strains which are not commonly found in wheat or rye sourdoughs. Yet, application of these strains as starter cultures for oat sourdoughs used for oat bread production revealed positive effects on loaf volume as a result of gas production by heterofermentative LAB, softening of the doughs and changes in the starch pasting properties.

Furthermore, the impact of HP was investigated on the major oat components, starch and protein which revealed starch gelatinisation and protein network formation at pressures ?‰? 350 MPa while a weakening of protein structures was observed at lower pressures. Addition of HP-treated oat batters to oat bread resulted in improved volume and decreased staling at 200 MPa, while higher pressures did not improve oat bread quality.

Source: VTT Technical Research Centre of Finland