Amino acid composition of algal products and its contribution to RDI.

In this paper, the amino acid profiles of algal products from diverse groups (Cyanophyceae, Chlorophyta, Rhodophyta and Phaeophyta) were established. Contents of essential and non-essential amino acids varied in the range of 22.8-42.3 and 31.0-66.5 (g·16 g(-1)N), respectively. In dependence on daily algal intakes, the highest participation in recommended daily intakes (RDI; related to adult, body weight of 70 kg) of all EAAs was observed in freshwater micro-algal products, especially from Spirulina genus where contribution ranged from 12.6% (Lys, SB) to 38.8% (Thr, S). Generally, Lys was the lowest contributor to RDIs in almost all algal samples except Chlorella pyrenoidosa (C) and Palmaria palmata (D), where Ile and Leu, respectively, were established. Interestingly, the contents of sulfur AAs of both products of the Spirulina genus covered 74.5% (S) and 73.8% (SB) of their RDI. Finally, products from brown seaweeds showed the lowest contributions to the RDIs of all EAAs.

Bioactive phenols in algae: the application of pressurized-liquid and solid-phase extraction techniques.

A new extraction technique based on the off-line combination of pressurized-liquid with solid-phase extraction (PLE-SPE) is described. The method was used for the extraction of bioactive phenolic acids (protocatechuic, p-hydroxybenzoic, 2,3-dihydroxybenzoic, chlorogenic, vanillic, caffeic, p-coumaric, salicylic acid), cinnamic acid and hydroxybenzaldehydes (p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, vanillin) from in vitro culture of two freshwater algae (Anabaena doliolum and Spongiochloris spongiosa) and from food products of marine macroalgae Porphyra tenera (nori) and Undaria pinnatifida (wakame). For the identification and quantification of the compounds the molecular ions [M-H](-) and specific fragments were analyzed by quadrupole mass spectrometry analyzer connected on-line with a reversed-phase HPLC system. Our analysis showed that the freshwater algae and marine algal products contained submicrogram or microgram level of above-mentioned phenols per gram of lyophilized sample. In addition, the total phenol content (Folin-Ciocalteu assay) and antioxidant activity (TEAC assay, Trolox equivalent antioxidant capacity assay) of the PLE-SPE extracts were determined and discussed.