Effect on bread properties of partial substitution of wheat flour with oat flour and flour from oat grain germinated in the light or dark

Native oat flour (NOF), light-germinated oat flour (LOF), and dark-germinated oat flour (DOF) were used to replace a portion of wheat flour to make bread. Adding 10% (w/w) oat flour contributed to a lower specific volume and darker crust and crumb than control, while light treatment during germination, significantly affected these three indices. Adding oat flour increased the hardness and chewiness values of bread crumbs by nearly 1-2-fold compared to the control. Adding oat flour especially germinated oat flour significantly increased the bio-accessible polyphenol content of bread. Compared to the control, the predicted glycaemic index (pGI) value of oat bread was substantially lower. Adding oat flour especially germinated oat flour to bread has the potential to increase bio-accessible phenolic content and decrease pGI value, but the successful application requires further studies to optimise formulation considering the poor textural characteristics.

Automated summary

In this study, native oat flour, light-germinated oat flour, and dark-germinated oat flour were used to partially replace wheat flour in bread making. Addition of 10% oat flour resulted in lower specific volume and darker crust and crumb compared to the control. Light treatment during germination significantly affected these three indices. Oat flour increased the hardness and chewiness values of bread crumbs, and germinated oat flour especially increased the bio-accessible polyphenol content and reduced the predicted glycaemic index value of bread.