# Properties and Functionality of Cereal Non-Starch Polysaccharides in Breadmaking
## 4 The Role of NSPs in Bread Making
### The Influence of NSPs on Bread Volume  
According to the literature, two kinds of bread's volumes are determined: the volume of bread baked from the same amount of dough and the specific bread volume expressed as bread volume per defined amount (100 g) of flour. The first parameter is commonly used and represents the structural properties of dough. The second one includes the structural properties of dough and also the yield of dough, which is related to the differences in water absorption. It was shown that the addition of AXs (in the range of 1-6%) had a positive effect on the volume of both wheat and rye bread (Table 3). The influence of the molar mass of AXs on the parameter mentioned above depends on the type of dough (wheat, rye) [76; 134; 154; 155; 163; 172; 173]. Moreover, in the case of rye bread, the addition of cross-linked AXs in the amounts of up to 3-6% resulted in an increase in bread volume by up to 18%, however at a higher share of such AX bread volume gradually decreased [83]. In the case of the addition of low molar mass AXs (partially hydrolyzed), the most pronounced effect on bread volume was observed when higher amounts of AXs were applied, and the increase in bread volume was up to 55% [83]. In a previous research study, it was shown that the addition of AXs obtained from other sources, such as flax mucilage, effectively improved the volume of gluten-free bread [174]. The analysis of the available literature shows that AXs are particularly promising NSPs in terms of improving not only the volume but also the overall quality of gluten-free bread.  
Information on the effect of the addition of \(\beta\)-glucans on the volume of bread is ambiguous, and further research is needed to be able to determine their effect on this parameter clearly. It has been shown that \(\beta\)-glucans have a positive effect on the volume of wheat bread, but this is correlated with their content and molar mass, as well as with the quality of the wheat flour used. The addition of 0.6% of high molar mass \(\beta\)-glucans obtained from barley grain resulted in an increase in the specific volume of wheat bread by as much as 37% [164]. In the case of gluten-free bread, the addition of 1% \(\beta\)-glucans increased the bread volume by 22.4%. On the other hand, the addition of \(\beta\)-glucans to gluten-free bread in the amount of 2% increased the bread volume by 8-16.5% [170]. However, based on some studies, the application of barley grain \(\beta\)-glucans at 5% to wheat bread resulted in a 28% reduction in bread volume [175], and the addition of both high and low molar mass \(\beta\)-glucans to wheat bread at the level of 4.5% resulted in a 53% and 44% decrease in bread volume, respectively [176]. It must be noted that in some research works, there is no information regarding compensation of higher water absorption caused by the addition of NSP, by additional amounts of water applied, and in the cases where this was not performed the dough could be too dense, and as a consequence the observed bread volume from the same amount of dough is lower compared to bread without the addition of NSPs.  
In the available literature, there are indications of the potential of other NSPs, such as galactomannans. For example, the addition of galactomannans from locust bean seeds at 2% to wheat bread increased its volume by 12% [169].