important characteristic is the high viscosity-forming
potential of b-glucans. In addition to the function as dietary
fibre, oat b-glucan has been associated with several other
health benefits. For instance, clinical studies have shown
that oat bran can be used to lower serum cholesterol levels
and to reduce the risk of heart disease [2]. The European
Food Safety Authority (EFSA) and the Food and Drug
Administration (FDA) granted a health claim on the
reduction of coronary heart disease by the ingestion of
whole-oat foods containing at least 0.75 g of soluble fibre
per reference amount customarily consumed (i.e. 50 g for
bread) [3, 4]. Additionally, oat b-glucan has been suggested
to have an important influence on human glycaemic
control by lowering the postprandial blood glucose level
[5–7]. An immune-stimulating effect of cereal b-glucan has
been indicated [8].
Inulin-type fructans are natural components of several
edible fruits and vegetables. The inulin commonly used in
the food industry derives from chicory and consists of oligosaccharides
and polysaccharides, which are composed of
fructose units connected by b (2 ? 1) links [9]. Inulin-type
fructans resist hydrolysis by human small intestinal digestive
enzymes and reach the large intestine virtually intact
where they are fermented by the intestinal microflora,
stimulating selectively the growth and/or activity of intestinal
bacteria associated with health and well-being [10, 11].
The many nutritional benefits of inulin and oat b-glucan
have been shown in several previous publications [7, 11–
15]. This work, however, focuses on the technological
aspects of the addition of these substances to bread. Previous
studies observed a decrease in loaf volume and
height, and firmer crumb structure upon the incorporation
of b-glucan in wheat bread formulas [16–18]. Lazaridou
et al. included oat b-glucan into gluten-free bread formulas
and reported an increase in loaf volume and a lighter crust
colour [19]. The objective of this particular study was to
determine the effect of inulin from chicory and b-glucan
originating from oat on the rheological properties of a
gluten-free batter compared to wheat dough as well as a
range of bread quality characteristics. The molecular
weight distribution of the b-glucan before and after the
addition to bread was determined. In addition, the influence
of inulin and oat b-glucan on the ultrastructural properties
of bread was evaluated.