# Evaluation of the Prospects for the Use of Microalgae in Functional Break Production
## 2 Materials and Methods
### Preparation of microalgae Bread Samples  
Microalgae samples were dried in a drying cabinet with natural convection ED 53 (Millab LLC, St. Petersburg, Russia) to a constant mass, ground into powder on a Pulverisette 14 rotary mill (Millab LLC, St. Petersburg, Russia). A 1:1 mixture of chlorella and spirulina was used to add to the bread. For research, bread samples were baked using a straight dough method. Estimated in preliminary tests, the levels of substitution of flour with a dry mixture of microalgae biomass during bread baking varied at 1% (0.5% spirulina and 0.5% chlorella), 3% (1.5% spirulina and 1.5% chlorella), and 5% (2.5% spirulina and 2.5% chlorella) (weight/weight). In a preliminary experiment, it was discovered that adding less than 1% of microalgae had no effect on the change in the properties of bread and that such samples were similar to the control ones (without the addition of microalgae), but adding more than 5% of microalgae caused a deterioration of the properties of bread (a fishy smell, an unattractive greenish color, and increased stickiness). It was difficult to determine the adequate taste of bread due to these defects. A mixture of microalgae was produced by cultivating separate samples of _A. platensis_ and _C. vulgaris_, two microalgae isolated from the Baltic Sea, in a Biostat A MO UniVessel Glass bioreactor (Sartorius Stedim, Gottingen, Germany), then drying them for 12 h at 30-40 \({}^{\circ}\)C to a moisture content of 5-6% in an oven with natural convection E 28 (Millab, Moscow, Russia). Next, the microalgae were ground on a P14 laboratory rotary mill (Millab, Moscow, Russia) into a powder with a size of 10-50 \(\upmu\)m. When baking bread, a mixture of _A. platensis_ and _C. vulgaris_ microalgae (1:1) was used instead of high grade wheat flour. According to the findings of the experiments (not presented in this paper), adding one of the types of microalgae (either chlorella or spirulina) did not result in bread samples with a porous, light texture, optimal organoleptic, physicochemical, structural mechanical properties, and, most importantly, increased antioxidant activity. A significant decrease in the amount of polyphenols responsible for the antioxidant properties of bread was observed in bread samples containing only one type of microalgae. The addition of a mixture of _A. platensis_ and _C. vulgaris_ (1:1) to bread samples resulted in the highest amount of volatile substances (alcohols, aldehydes, ketones, ethers, volatile sulfur compounds, terpen, acids, and hydrocarbons) and polyphenols, resulting in the presence of high antioxidant activity in the samples. With the straight dough method, filtered water, \"Voronezhskie\" yeast (SAF-Neva LLC, Voronezh, Russia) salt and sugar were added to the bowl, according to the formulation for 100 kg of flour (Makfa, St. Petersburg, Russia), presented in Table 4, were mixed, flour and dry biomass of microalgae were added. The mixture was mixed until smooth. The dough was fermented for 30 min, then was formed into loaves. The dough was divided into pieces taking into account the oven loss and drying loss. The formed dough pieces were laid on the trays and sent for proofing. The duration of proofing was 50 min. The rested test pieces were baked for 25 min at a temperature of 210 \({}^{\circ}\)C in the bakery oven EShP-ZKP (LLC \"Klyon\", St. Petersburg, Russia). After baking, the loaves were placed on trays and, if necessary, thrown out.