Researchers from the University of Valladolid, Spain, report that the extrusion of wheat bran before its use in high fibre bread could improve the quality and characteristics of both the bread dough and the final loaf.
Published in LWT - Food Science and Technology, the research investigates the effect of bran extrusion on bread quality, reporting that using extruded bran also reduces the loss of dough height during fermentation to a greater extent than untreated bran, and produces a higher volume and better firmness than breads with normal bran.
“Despite of the increased price of extruded bran, it constitutes an interesting alternative in breads with bran compared to normal (non-extruded) bran,” said the researchers, led by Manuel Gómez, from the University of Valladolid.
“There were only minimal differences in acceptability between breads with the different types of bran and, in some cases, the extruded bran showed a clear advantage,” they added.
Bran is often used to enrich breads (notably muffins) and breakfast cereals, especially for the benefit of those wishing to increase their intake of dietary fibre.
In addition to being a rich source of fibre, bran has also been shown to be high in vitamins and minerals, whilst it also has high antioxidant content.
However, the addition of bran can have negative consequences on bread volume and certain sensory properties, noted the authors.
The researchers investigated the effect of bran extrusion on the rheological characteristics of bread dough, behaviour during fermentation, and final bread quality, by adding between 2.5 and 20 per cent bran to bread dough.
Gómez and colleagues reported that extruded bran increased dough development time and tenacity to a greater extent than non-extruded bran, whilst it also minimized the loss of stability if over-mixing occurred.
“Extruded bran, due to its greater gas production, also reduced loss of dough height during fermentation to a greater extent than untreated bran,” said the researchers.
They added that no differences were found in the sensory evaluation.
“Bran extrusion therefore modified dough rheology but did not negatively affect bread quality,” said the researchers.
“It could even improve the quality of breads with bran when improvers are added,” they added.
Source: LWT - Food Science and Technology
Published online ahead of print, doi: 10.1016/j.lwt.2011.06.006
“Effect of extruded wheat bran on dough rheology and bread quality”
Authors: M. Gómez, S. Jiménez, E. Ruiz, B. Oliete