Seasonal variations in the chemical composition of Arctic brown macroalgae

The dynamics of White Sea macroalgae chemical composition during the growing season (June-September) was analysed. The study revealed an increase in the content of polyphenols (from 5.35%dw-6.02%dw to 14.66% dw-16.80%dw), a high level of pigments (chlorophyll a (up to 0.134%dw), carotenoids (up to 0.036%dw)), and saturated fatty acids (up to 3.206%dw (90%rel)), which is most likely due to solar, photosynthetic activity, as well as elevated seawater temperature. The optimal month to collect macroalgae, with the maximum content of valuable chemical compounds of lipophilic fractions, carbohydrates and proteins is August. Priority species have been identified for the selective production of individual fractions of algae biomass components. Fucaceae (Ascophyllum nodosum, Fucus vesiculosus) species are preferable for the isolation of lipophilic components and minerals, Laminariaceae (Laminaria digitata, Saccharina latissima) species are preferable for the isolation of carbohydrates (alginates, mannitol, cellulose). A comparative analysis of the content of the main groups of Arctic brown algae biomass with macroalgae from Europe, the Far East, and Southeast Asia was carried out. It is shown that the White Sea species have high potential as a promising new source of lipophilic substances (polyphenols, pigments, fatty acids), as well as cellulose.