Wheat germ stabilization by heat-treatment or sourdough fermentation: Effects on dough rheology and bread properties

The aim of this work was to evaluate the effects of wheat germ -stabilized by toasting or by sourdough fermentation -on dough and bread properties.Doughs were produced by adding increasing amounts of each type of stabilized germ, starting with the current recommended level of 3g/100g up to 20g/100g.Sourdough fermentation ensured the presence of lactic acid bacteria (LAB) in amounts comparable to those found in conventional sourdough.The acidification induced by LAB inactivates lipase and lipoxygenase, as does the toasting process.These results decreased the phenomena of rancidity, as demonstrated by the low development of hexanal during storage.Fermentation significantly decreased the content of glutathione, responsible for the deterioration of the rheological characteristics and workability of dough containing high levels of germ.Dough enriched with fermented germ exhibited high stability during mixing and development.Positive effects associated with the use in bread-making of germ stabilized by fermentation have been detected both in fresh bread (high specific volume) and in bread samples stored up to 4 days in controlled conditions of humidity and temperature.Finally, the sensory consumers' test confirmed that the addition of fermented germ did not diminish the liking of the sample.