# Evaluation of the Prospects for the Use of Microalgae in Functional Break Production
## 4 Discussion
Moisture loss during storage was 8.8%, 5.1% and 4.9% for bread with the addition of 1%, 3% and 5% microalgae, respectively. Replacing wheat flour with different amounts of microalgae biomass did not affect the pH and a \({}_{\text{w}}\) of bread with the addition of 1% and 3% (Table 7). However, with the addition of 5% microalgae, the pH shifted towards more acidic values. A decrease in a \({}_{\text{w}}\) was observed in bread samples with the addition of 3% and 5% microalgae during storage, which is probably caused by a higher loss of moisture during storage. Similar values of a \({}_{\text{w}}\) were also observed in bread enriched with biologically active ingredients [25]. A higher density of bread often correlates with increased hardness. However, no statistically significant differences were found in the current study. Similar results were observed after adding freeze-dried broccoli by-products to bread at a concentration of 2% [27]. The observed increase in hardness on the 3 rd day compared to the values obtained on the day of baking may be due to the staling of bread and the loss of moisture. In addition, there were no significant differences in elasticity, cohesivity, stickiness, ease of chewing and stability between bread containing 1% and 3% microalgae, which suggests a comparable sensation in the mouth and similar preservation of textural properties after self-pressing, both on the 1 st and 3 rd day of baking. As for bread with the addition of 5% microalgae, the density and the coefficient of stickiness increased, while the coefficient of elasticity and the coefficient of resistance to crumbling decreased. The results were consistent with the results obtained in [23]. Similar results were observed earlier in other food products, where the addition of microalgae did not affect their functional properties [23, 36]. Currently, polyphenols derived from algae are one of the main ingredients of functional nutrition for the prevention of cardiovascular diseases and diabetes mellitus [37]. The addition of microalgae led to an increase in polyphenols in both samples of bread with microalgae and, as expected, to an increased antioxidant capacity (Table 9). Several studies report high antioxidant activity of microalgae biomass due to the high content of phenols and carotenoids [38]. There was a positive correlation between the amount of phenolic compounds and their antioxidant capacity. The antioxidant capacity of bread with microalgae was 0.894 for bread with the addition of 1% microalgae, 0.998 for bread with the addition of 3% microalgae and 1.000 for bread with the addition of 5% microalgae (FRAP method) and 0.874 for bread with the addition of 1% microalgae, 0.999 for bread with the addition of 3% microalgae and 1.100 for bread with the addition of 5% microalgae (DPPH method). Other studies have also reported an increased content of polyphenols and a higher antioxidant capacity after the addition of microalgae to pasta [36] or broccoli to bread [26]. The amount of polyphenols (Table 9) in enzymatic digestive extracts obtained after imitation of gastrointestinal digestion is higher in bread with the addition of 5% microalgae than in bread with the addition of 1% and 3% microalgae. This is probably caused by a higher release of polyphenols under the action of digestive enzymes. A longer extraction time may also partially explain these results. Not only the content of phenols, but also the antioxidant capacity of enzymatic digestive extracts of bread with the addition of 5% microalgae were higher than the ones of bread with the addition of 1% and 3% microalgae. The observed increase in antioxidant capacity with an increase in the content of microalgae in bread may be associated with a higher content of phenols, as well as with the creation of bioactive peptides with antioxidant capacity, as shown in studies [39; 40], in which microalgae were sources of bioactive peptides. When digesting bread with microalgae, the bioavailability of biologically active substances with beneficial nutritional properties increases [41].