# The Clean Label Concept: Novel Approaches in Gluten-Free Breadmaking
## 8 Prospective Gluten Substitutes with Clean Label Status  
### Beta Glucan  
\(\beta\)-glucans are the primary constituents of the cell walls of cereal grains. Oat and barley have been found to contain 70% \(\beta\)-(1\(\rightarrow\)4)-linked and 30% \(\beta\)-(1\(\rightarrow\)3)-linked \(\beta\)-d-glucopyranosyl residues organized in blocks of \(\beta\)-(1\(\rightarrow\)4)-linkage sequences (cellotriosyl and cellottarosyl cellulose-like segments) separated by single \(\beta\)-(1\(\rightarrow\)3)-linkages [57]. Other types of \(\beta\)-glucan [(1\(\rightarrow\)3), (1\(\rightarrow\)6) \(\beta\)-glucan] have been found in fungi. However, due to their different structure, such \(\beta\)-glucan have totally different properties. Physical properties, such as water solubility, water binding capacity, wettability (how easily the powder sinks in water), dispersibility (the ability of the powder to distribute homogeneously in water when stirred), and viscosity, as well as gelation properties result from the molecular and structural features of cereal \(\beta\)-glucans [58]. Usage of the \(\beta\)-d-glucan rich oat and barley fractions at certain concentrations, may lead to loaf volume increase [59]. This can be explained by the increase in dough viscosity, which is itself due to the high water binding capacity of \(\beta\)-d-glucan. In wheat baked goods, (1\(\rightarrow\)3)(1\(\rightarrow\)4) \(\beta\)-d-glucans have a positive effect on crumb grain. They seem to stabilize air cells in the bread dough and prevent coalescence of the cells. This may result in a reduction in the mean cell size [60]. High molecular weight (1\(\rightarrow\)3)(1\(\rightarrow\)4) \(\beta\)-d-glucans have a large surface area per unit of weight. This enables them to improve the extensibility of the dough and to stabilize gas cells. An aspect of gas cell stabilization was analyzed by [PERSON] et al. [61], who suggested that a large quantity of fluid was structured in the dough phase, thereby improving the mechanical strength of the liquid film. This dual film hypothesis was confirmed by [PERSON] et al. [62]. The possible existence of the coalescence and disproportionation of gas cells phenomenon at the end of proofing process, as well as in the early baking stages of breadmaking is limited by liquid lamellae [62]. From a physiological point of view, \(\beta\)-d-glucan forms a viscous gel in the stomach, which traps nutrients and slows the digestion of food by digestive enzymes. This results in slower gastric emptying and steady, more sustained absorption of sugars, reducing the post-prandial glycaemic response. In Europe, EFSA and the European Commission have granted two health claims of oat \(\beta\)-d-glucan (European Commission Regulation, Article 13.1) [63]. [PERSON] et al. explored the impact of replacing part of the hydrocolloids blend with \(\beta\)-d-glucan [64]. They concluded that 0.5-1.0% \(\beta\)-d-glucan had no significant effect on bread quality parameters (mass, volume, yield and total baking loss). Baked goods were highly sensory-rated by consumers (classified as first quality class). The use of 1.5% \(\beta\)-d-glucan did not have a significant effect on most of the qualitative features of the final product, except for reducing the volume. Additionally, these breads were classified the same way although they had a smaller volume. Increasing the \(\beta\)-d-glucan content (up to 2.5%) resulted in a significant deterioration of quality attributes resulting in sensory disqualification by consumers. [PERSON] et al. [65] studied the application of \(\beta\)-d-glucan in gluten-free yeast leavened cake. Experimental samples were prepared with different amounts of \(\beta\)-D-glucan. The reference structuring agent was HPMC. Both \(\beta\)-D-glucan and water had a significant impact on the gluten-free yeast-leavened cake. The oat \(\beta\)-D-glucan not only increased the specific volume and lightness, but also decreased the color and firmness.