## 3 Results and Discussion
### Textural Behavior of Gluten-Free Matrices  
Figure 5 shows the (a) firmness, (b) adhesiveness, (c) cohesiveness and (d) springiness of the proposed gluten-free gelled matrices enriched with selected extracts (E1-E7). In general, all parameters exhibited higher values for those gelled matrices formulated with hybrid carrageenanan, which is consistent with the results found during thermorheological testing. The firmness of the tested matrices was notably influenced by the presence of the soluble antioxidant extracts for both the hybrid carrageenanan (E4 > E7 > E5 > E6 \(\approx\) E2 > E1 > E3) and starch (E4 > E7 > E5 \(\approx\) E6 \(\approx\) E2 \(\approx\) E1 > E3) matrices (Figure 5a). Anyway, the magnitudes of this parameter were over the range that was reported for other gluten-free matrices using different gelling agents for food purposes [22; 26]. The adhesiveness values varied between 0.43 and 0.35 for the hybrid carrageenanan matrices and between 0.22 and 0.18 for the potato starch ones (Figure 5b). The highest adhesiveness values were identified for E7, E5 and E1 with no significant differences when compared with the control sample (C1). For the starch gels, similar values were observed for all extracts apart from E3, where  
the lowest adhesiveness was found. The magnitudes of the adhesiveness were consistent with previous results for other food matrices [27; 28]. The cohesiveness exhibited similar trends to those observed for firmness, although lower differences between the matrices prepared with both gelled agents were observed in this case (Figure 5c). It should be noted that the matrices incorporated with E7 featured the highest cohesiveness values, even higher than the control for the starch gelled systems (S1). The springiness followed the tendencies aforementioned for the viscoelastic behavior monitored during the mechanical spectra of the developed gelled matrices. Again, the gels in the presence of E7 and E4 led to the highest values of this parameter for enriched systems, whereas those incorporated with E3 featured the lowest springiness values. The magnitudes were in accordance with those previously reported for other biopolymer-based gelled systems proposed for the food field [22], even though a wide range of gelled matrices with suitable characteristics from a food point of view were developed.  
Figure 3: Viscoelastic features of the proposed matrices, prepared with **(a-c)** hybrid carrageenanan or **(d)** potato starch in the presence of extract from _Camellia sinensis_ agricultural wastes and industrial hops (see Table 1 for coding). Note here that C1 and S1 are the controls prepared with hybrid carrageenanan and potato starch, respectively.  
Figure 4: Heating profiles for (**a**) control matrices prepared with the hybrid carrageenan (C1) or potato starch (S1), as well as (**b**) the corresponding melting temperatures \(\mathrm{T_{m}}\) for all formulated matrices. Note than in this and subsequent plots, error bars were not presented whenever they were smaller than the symbol size.  
Figure 5: Texture parameters in terms of (**a**) firmness, (**b**) adhesiveness, (**c**) cohesiveness and (**d**) springiness for the proposed matrices prepared with hybrid carrageenan or potato starch in the presence of selected extracts (E1–E7; see Table 1). The controls prepared with hybrid carrageenan (C1) and potato starch (S1) were also included.