## 1 Introduction
In addition, a fishy taste could be used positively to improve the taste of vegan pasta dishes with fish (sauce) alternatives. Many different microalgae (_C. vulgaris_, Spirulina, _Isochrysis galbana_, _Diacronema vlkanum_, _Dunaliella salina_, _Nannochloropsis_ sp.) have already been added to pasta products to enhance the nutritional content or antioxidant potential [18; 19; 20; 21; 22; 23; 24; 25; 26]. However, only a few studies have looked at the changes in the physical properties of pasta with different algae concentrations and their sensory acceptance. [PERSON] et al. [25] showed that although the content in the \(\omega\)-3, poly-unsaturated fatty acid eicosapentaenoic acid (EPA) in pasta increased with increasing concentrations of the green microalgae _Nannochloropsis_ (10-40%), the optimum cooking time, water adsorption, and swelling index decreased, indicating a significant impact of the microalgae on starch swelling and gelatinization. Besides textural changes, the sensory evaluation revealed reduced global acceptability at all microalgae concentrations compared to the control [25]. [PERSON] et al. [26] showed that the addition of 1-3% green _D. salina_ to pasta slightly improved nutritional parameters but resulted in reduced dough stability and, therefore, strength with increasing algae concentrations. Besides color changes, the swelling and cooking loss of the pasta increased, indicating the destabilization of the structure. However, flavor and overall acceptability scores were quite high for all samples (>8 on a 10-point scale) [26]. For spaghetti supplemented with the golden-brown microalgae _I. galbana_ and _D. vlkanum_ (0.5-2.0%), a significant increase in EPA and docosahexaenoic-hexaoic acid (DHA) was reported, but again, the quality parameters of optimal cooking time, cooking loss, swelling index, and water absorption changed. Sensory evaluation revealed a fishy flavor for samples containing 2.0% algae, while all other attributes (color, odor, texture, global appreciation) decreased with increasing algae concentration, especially for spaghetti supplemented with _D. vlkanum_[24]. The same authors reported similar findings for spaghetti containing 0.5-2.0% _C. vulgaris_ (green or orange strains) or Spirulina. In particular, the sensory evaluation indicated lower scores for the attributes of odor and flavor when 2% green (fishy) algae was added, while the orange _C. vulgaris_ strain was most preferred by the panelists [19]. All previous studies show that the use of microalgae in food and pasta is limited to concentrations of 2-3% due to strong sensory changes. However, in order to achieve a measurable added value for the marketing of algae pasta through substitution with microalgae [16], significantly higher concentrations would have to be used. The use of microalgae in food should, therefore, be seen as a nutritional enrichment (introduction of small amounts of macro- and micronutrients), but its use as a source of protein is difficult. In this study, the effect of 3 and 5% addition of four strains of _C. vulgaris_ on pasta was tested. The aim was to determine the most suitable strain in terms of physical stability and sensory evaluation and to develop a marketable product. Three working hypotheses were formulated from the literature above: (1) the physical changes of pasta caused by microalgae are dependent on concentration, species, and/or strain; 2) different algae species and/or strains can introduce different colors and flavors, which have different effects on sensory acceptance; and (3) independent of color, the absence of fishy odors and flavors will positively contribute to pasta acceptability. To test the hypotheses, durum wheat semolina was supplemented with 0.0, 3.0, and 5.0% differently colored (green, yellow, and white) _C. vulgaris_ strains, namely Smooth _C. vulgaris_ (SCV, green), Honey C. _vulgaris_ (HCV, yellow), White _C. vulgaris_ (WCV, white), and New Honey _C.