## 4 Discussion
However, the water absorption for samples with the addition of dG decreased significantly and the firmness increased, which can be explained by the increased protein content (~17% compared with 11%) resulting in a more compact protein network. This is in accordance with the findings from [PERSON] et al. [25] and [PERSON] et al. [26], who reported increased firmness and a denser inner structure above gluten concentrations of 13 and 14%, respectively. However, they also reported an increase in optimal cooking time, indicating reduced starch swelling due to the higher density [25; 26]. Similar findings have been made by [PERSON] and [PERSON] [45] when substituting 40% wheat semolina with mixtures of soy and mung flour, resulting in protein concentrations above 18% and enhanced cooking time [45]. In contrast, substituting durum wheat semolina with lupin flour shortened the cooking time from substitution concentrations above 40%, which corresponded to protein and fiber contents above 25% and 12%, respectively [46]. [PERSON] et al. [30] reported that the addition of 3-5% carob fiber significantly shortened the cooking time of wheat flour pasta. The addition of both components (dG and AF) could therefore cancel out the effect of a more condensed protein network on starch swelling due to interaction. Further analyses, e.g., observation of the structure using scanning electron microscopy, would be necessary to better understand the changes. Mixtures of CV + dG and CV + dG + AF show an even higher firmness than pasta with dG alone, which might be explained by a slight increase in protein content and a more pronounced increase in the fiber content. A fiber type and concentration-dependent increase in hardness of pasta has already been described by [PERSON] et al. [27]. Interestingly, samples containing CV or AF only did not differ in firmness from the control, while the CV + AF samples resulted in a firmness comparable to the CV + dG and CV + dG + AF samples, though the protein content was much lower (11%). Therefore, in this case too, the interaction of the individual components appears to have a decisive influence on firmness due to the altered composition and the associated effects on the protein network density and starch swelling as well as the addition of fibrous structures that mediate additional bite resistance. The regression analysis of sensory acceptance showed no dependence on specific sensory parameters. However, the samples with the highest typical odor and the lowest fishy/off odor and after/off taste had the highest acceptance (control = dG > AF). Only by adding 3 and 5% CV does acceptance decrease dramatically. This is consistent with previous studies showing that the addition of 5% _C. sorokiniana_ and 2% CV already leads to a significant reduction in acceptance due to the fishy odor and taste [17; 23]. The fishy/algae odor and taste, as well as an increased taste intensity, have also been identified as the main differences from commercial pasta by the Spanish panelists. Mixtures of CV + dGand CV + AF showed higher acceptance levels than the CV samples alone, which could be explained by the results of [PERSON] et al. [4], showing that the preservation of the typical pasta odor was more significant for the acceptance of algae pasta than the presence of a fishy/off odor or after/off taste. Nevertheless, besides the taste, CV samples contain chlorophyll and carotenoids, important macro- and microelements (e.g., iron, manganese, copper and zinc), and high contents in B vitamins [5; 8; 47; 48]. Based on former analyses [48], pasta with 3% CV may contains 0.6 ug vitamin B12. This is particularly interesting for a vegan diet, as there are no other plant-based sources of vitamin B12. However, 700 g of 3% CV pasta would have to be consumed to cover the daily requirement of 4 ug [49]. Moreover, in contrast to products containing soybeans and peas, the market for microalgal food is still in its early stages in Europe, which might be explained by higher prices as well as dietary preferences, habits and attitudes [20; 22].