## 3 Results and Discussions
### Final Products Characterization
#### 3.2.6 Rheological Evaluation of Products  
In the present study, the following textural parameters have been analyzed: total work, hardness, cohesiveness, springiness, chewiness, gumminess and adhesiveness, as listed in Table 9.  
The principal mechanical characteristic of solid foods is represented by hardness [70]. This parameter is defined as the force needed to obtain a given deformation of the product [36]. In the present study, hardness 1 and 2 values increased as the percentage of buckwheat flour increased. The same pattern was observed on the final baked products manufactured with different percentages of SF flour. The explanation for the hardness 1 and 2 increased values could be the reduction of gluten content matrix, considering that BW and SF flours are gluten free. This is in line with [PERSON] et al. [43], who reported that the dough reduction in gluten matrix could lead to a harder bread texture. Furthermore, [PERSON] et al. [71] showed that gluten matrix is also involved in the elasticity of the dough and its capacity to retain gases during fermentation process, having a key role in bakery foods manufacture.  
On the other side, the use of guar gum and Magimix improver, lead to significantly different values for hardness 1 and 2 (Table 9). For instance, for hardness 2, the samples manufactured with Magimix registered lower values, than those made with guar gum. This could be due to the chemical composition of Magimix, mainly to alpha-amylase content which could be involved in the improvement of dough properties. In this light, [PERSON] et al. [72] reported that improvers with alpha-amylase could enhanced bread texture and elasticity. Moreover, it is important to mentioned that Magimix contains also xylanase, which positively influenced the bread hardness, as reported by [PERSON] et al., [73]. Likewise, [PERSON] et al. [27] proved that guar gum had no significant influence on the crust of the white bread, therefore, its hardness. The chewiness and gumminess parameters, showed proportional trends with hardness, samples with 0.2% guar registered higher values than samples with 0.2% improver.  
On the other hand, regarding the cohesiveness, a parameter used to describe the internal cohesion of the material [36], the products manufactured with guar gum, showed better results. Cohesiveness value is desirable to reach a high value because it helps to form a bolus during mastication process, instead of disintegration of the product [74]. This is in concordance with [PERSON] et al. [74] who demonstrated that gum improved cohesiveness even in the gluten free products. In the same light, [PERSON] et al. [75] proved that the moisture content of the final baked goods could be involved in lowering cohesiveness and chewiness values. In the present study, the moisture content of the buns manufactured with different percentages of BW changed, reaching higher value when 30% BW was added, meanwhile in SF final baked goods no statistical differences were noticed (Table 6).  
Springiness is a textural parameter linked to freshness and elasticity of the final baked products [75] and therefore is desirable to have high values. Samples with guar gum registered higher values that those with improver (Table 4). [PERSON] et al. [27] demonstrated that guar gum could improve dough stability and could enhance the elasticity of the final baked product.  
Adhesiveness is defined as the necessary force needed to remove the product to the palate with tongue help [76]. In the present study, the adhesiveness of the final baked products made with guar gum were statistically different that those made with improver. This could be explained by the capacity of guar gum to have a positive influence on the dough stickiness, as reported by [PERSON], [77].