Seasonal Changes in the Nutritional Composition of Agarophyton vermiculophyllum (Rhodophyta, Gracilariales) from the Center of Portugal

Abstract

Seaweeds exhibit high nutritional value due to a balanced concentration of proteins, vitamins and minerals, a high concentration of low digestibility polysaccharides, and reduced levels of lipids, many of which are n-3 and n-6 fatty acids. The species Agarophyton vermiculophyllum is no exception and, as such, a comprehensive study of the chemical and nutritional profile of this red seaweed was carried out for 1 year. Seasonal variations in moisture, ash, protein and amino acids content, crude fibers, ascorbic acid, agar, lipids, and the corresponding fatty acid profile, were analyzed. We found low levels of fatty acids and a high protein content, but also noticed interesting seasonal change patterns in these compounds. The present study gives insights on the environmental conditions that can lead to changes in the nutritional composition of this species, aiming, therefore, to bring new conclusions about the manipulation of environmental conditions that allow for maximizing the nutritional value of this seaweed.

Seasonal Nutritional Profile of Gelidium corneum (Rhodophyta, Gelidiaceae) from the Center of Portugal

“…It is, however, slightly lower compared to the red algae G. vermiculophylla (% ≈22), Osmundea pinnatifida (% ≈20), Porphyra sp. (% ≈25), and Pterocladiella capillacea (% ≈20), which are traditionally used in the food industry [69,85,89,90]. These data corroborate that those seaweeds are an interesting source of protein.…”

“…Thus, environmental conditions have an impact on the production of different FA, with PUFA being produced mainly during summer and SFA during winter. This seasonal variation has been registered before for red seaweeds [55,69,82], but with an increase in PUFA during summer. The mild temperatures recorded in Portugal, in the central area, may have less impact on PUFA production, and other environmental conditions such as nutrient availability, light intensity during summer, salinity, and the physiological state of the thalli, or the life cycle of the species itself, may influence the production of these primary metabolites [46,83].…”

“…In G. corneum, although ash values were low compared to other Gelidium species such as G. pusillum (21.2% dw), it is still within the expected range for red seaweeds (5.8-46.2%) [68]. In our study, this value reached a maximum of 14.12 ± 0.85%, indicating a relatively low mineral richness when compared to Gracilaria vermiculophylla (formerly Agarophyton vermiculophyllum) and Gelidium pusillum [68,69].…”

“…These values are similar or lower than those presented for Porphyra sp. (1.1-1.3), G. vermiculophylla (0.63-2.02), Gracilaria gracilis (2.1-2.6), and Chondrus crispus (8.4-9.2) [69]. Thus, environmental conditions have an impact on the production of different FA, with PUFA being produced mainly during summer and SFA during winter.…”

In Vitro Evaluation of the Antibacterial and Antioxidant Activities of Extracts of Gracilaria gracilis with a View into Its Potential Use as an Additive in Fish Feed

“…In the laboratory, the biomass was thoroughly washed in seawater and the necrotic parts and epiphytes were removed. Healthy portions were selected, packaged, and stored at −20 • C. Before the extraction procedures, the thalli were dried at 25 • C in a ventilated laboratory oven (Binder, FD115) during the course of 48 h until reaching a constant weight, were reduced into powder in a blender, and then were sieved (particles smaller than 200 µm) [35]. Seaweed powder was stored at −20 • C.…”